138 results on '"Qixing Zhou"'
Search Results
2. Integrating FTIR 2D correlation analyses, regular and omics analyses studies on the interaction and algal toxicity mechanisms between graphene oxide and cadmium
- Author
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Kangying Wu, Yuhao Li, Qixing Zhou, Xiangang Hu, and Shaohu Ouyang
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Spectroscopy, Fourier Transform Infrared ,Environmental Chemistry ,Graphite ,Chlorella vulgaris ,Pollution ,Waste Management and Disposal ,Ecosystem ,Cadmium - Abstract
Graphene oxide (GO, a popular 2D graphene-based nanomaterial) has developed quickly and has received considerable attention for its applications in environmental protection and pollutant removal. However, significant knowledge gaps still exist about the interaction characteristic and joint toxicity mechanism of GO and cadmium (Cd) on aquatic organisms. In this study, GO showed a high adsorption capacity (120. 6 mg/g) and strong adsorption affinity (K
- Published
- 2022
3. Regulation of rhizospheric microbial network to enhance plant growth and resist pollutants: Unignorable weak electric field
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Xiaolin Zhang, Jintong Song, Wenqing Yan, Tian Li, Ruixiang Li, Jinning Wang, Xin Wang, and Qixing Zhou
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Environmental Engineering ,Bacteria ,Plant Development ,Plants ,Pollution ,Plant Roots ,Hydrocarbons ,Biodegradation, Environmental ,Rhizosphere ,Endophytes ,Environmental Chemistry ,Soil Pollutants ,Environmental Pollutants ,Waste Management and Disposal ,Soil Microbiology - Abstract
The union of Plant Growth-Promoting Bacteria (PGPB) and rhizosphere confers a series of functions beneficial to plant. However, the lack of an opearable in situ method limits the further understanding on the mechanism. In this study, a weak electric field was designed to regulate rhizospheric microflora in a constructed root-splitting reactor. Compared with the control, the aboveground and underground biomass of rice seedling increased by 17 % and 18 % (p0.05) respectively under the exist of weak electric field of 0.14 V/cm. The joint action of rhizosphere and PGPB displayed the detoxification ability in the condition of soluble petroleum hydrocarbons, where the height, stem diameter, biomass and root vigor of the plant was increased by 58 %, 32 %, 43 % and 48 % respectively than the control. The selective reproduction of endophytes and ectophytes (denitrifying, auxin-producing, hydrocarbon-degrading and electroactive bacteria) was observed under applied weak electric field, which enhanced the nitrogen utilization, cellular metabolic activity and resistance to toxic organics of plant. This was further confirmed by the up-regulated OTUs related to the hydrocarbon degradation function, tryptophan metabolism and metabolism of nicotinate and nicotinamide. Moreover, the weak electric field also enhanced the transfer ability of partial endophytes grown in the root to improve plant stress resistance. The results in this work inspired an exercisable method for in situ enrichment of PGPB in the rhizosphere to cope with food crisis and provided a new way to deal with sudden environmental events.
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- 2022
4. Effect of natural soil nanocolloids on the fate and toxicity of cadmium to rice (Oryza sativa L.) roots
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Shaohu Ouyang, Qixing Zhou, Zhicheng Bi, Jing Sun, and Xiangang Hu
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Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
5. Natural nanocolloids regulate the fate and phytotoxicity of hematite particles in water
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Shaohu Ouyang, Qixing Zhou, Peng Yuan, Yang Gao, Jing Sun, Wei Zou, and Xiangang Hu
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Environmental Engineering ,Ecological Modeling ,Pollution ,Waste Management and Disposal ,Water Science and Technology ,Civil and Structural Engineering - Published
- 2023
6. Improving the uptake of PAHs by the ornamental plant Sedum spectabile using nano-SiO2 and nano-CeO2
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jianv liu, Yaping Wang, Mingzhu Wang, Rongrong Liu, Xiaoting Feng, Zijin Xue, and Qixing Zhou
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History ,Environmental Engineering ,Polymers and Plastics ,Environmental Chemistry ,Business and International Management ,Pollution ,Waste Management and Disposal ,Industrial and Manufacturing Engineering - Published
- 2023
7. Energy efficient portable air cathode electrochlorinator for point-of-use disinfection of toilet wastewater
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Zhihui Ma, Haitao Wang, Qixing Zhou, Bolong Liang, Mingmei Li, Pengfei Wang, and Sihui Zhan
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
8. Enhanced carbon emission driven by the interaction between functional microbial community and hydrocarbons: An enlightenment for carbon cycle
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Zelin Hou, Qixing Zhou, Fan Mo, Weilu Kang, and Shaohu Ouyang
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Environmental Engineering ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2023
9. Effects of co-modified biochar immobilized laccase on remediation and bacterial community of PAHs-contaminated soil
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Zeqi Zheng, Weitao Liu, Qixing Zhou, Jiantao Li, Aurang Zeb, Qi Wang, Yuhang Lian, Ruiying Shi, and Jianlin Wang
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Soil ,Environmental Engineering ,Bacteria ,Steel ,Health, Toxicology and Mutagenesis ,Laccase ,Environmental Chemistry ,Polycyclic Aromatic Hydrocarbons ,Pollution ,Waste Management and Disposal - Abstract
Considering the stability and economy of immobilized enzymes, this study prepared co-modified biochar immobilized laccase product named Fe
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- 2023
10. Polycyclic musks in the environment: A review of their concentrations and distribution, ecological effects and behavior, current concerns and future prospects
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Qixing Zhou, Qingqin Zhou, Yu Zhang, Linfang Zhu, Jianv Liu, and Wenying Zhang
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Pollution ,Environmental Engineering ,business.industry ,media_common.quotation_subject ,0208 environmental biotechnology ,Distribution (economics) ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,020801 environmental engineering ,Environmental protection ,Chemical products ,Environmental science ,Current (fluid) ,business ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,media_common - Abstract
Polycyclic musks (PCMs) are widely used in daily chemical products, so their mass production and wide use enable them to enter the environment in various ways. Their lipophilicity and persi...
- Published
- 2020
11. Nano-Ag: Environmental applications and perspectives
- Author
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Fan Mo, Qixing Zhou, and Yuqing He
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Environmental Engineering ,Silver ,Environmental Chemistry ,Metal Nanoparticles ,Surface Plasmon Resonance ,Reactive Oxygen Species ,Pollution ,Waste Management and Disposal ,Anti-Bacterial Agents ,Nanostructures - Abstract
Silver nanoparticles (AgNPs) are promising bactericidal agents and plasmonic NPs for environmental applications, owing to their various favorable properties. For example, AgNPs enables reactive oxygen species (ROS) generation, surface plasmon resonance (SPR), and specific reaction selectivities. In fact, AgNPs-based materials and their antimicrobial, optical, and electrical effects are at the forefront of nanotechnology, having applications in environmental disinfection, elimination of environmental pollutants, environmental detection, and energy conversions. This review aims to comprehensively summarize the advanced applications and fundamental mechanisms to provide the guidelines for future work in the field of AgNPs implanted functional materials. The state-of-art terms including (photo)(electro)catalytic reactions, heterojunction formation, the generation and attacking of ROS, genetic damage, hot electron generation and transfer, localized surface plasmon resonance (LSPR), plasmon resonance energy transfer (PERT), near field electromagnetic enhancement, structure-function relationship, and reaction selectivities have been covered in this review. It is expected that this review may provide insights into the rational development in the next generation of AgNPs-based nanomaterials with excellent performances.
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- 2021
12. Derived regional soil-environmental quality criteria of metals based on Anhui soil-crop systems at the regulated level
- Author
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Yong Teng, Yuanyuan Ke, Qixing Zhou, Riqiang Tao, and Youbao Wang
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China ,Soil ,Environmental Engineering ,Metals, Heavy ,Environmental Chemistry ,Soil Pollutants ,Pollution ,Waste Management and Disposal ,Risk Assessment ,Triticum ,Cadmium ,Environmental Monitoring - Abstract
Anhui province is a big agricultural province in China with regional heterogeneity, but there is still a lack of its regional soil-environmental quality standard for food safety and agricultural land protection. Herein, we collected 42 typical soil samples and 125 crop samples (roots, shoots and grains of wheat and rape) in the typical regions of northern, middle and southern Anhui province, and derived the regional criteria based on the current levels of eight metals (Cd, Cr, As, Pb, Hg, Cu, Zn, and Ni) as the basic items. Results showed that the metal concentrations in soil and crop samples varied with different Anhui regions and soil-crop systems. It was observed that there exists slight or moderate soil pollution (0.77-2.67), significantly higher concentrations (P0.05) in rape soils, generally higher concentrations (P0.05) in wheats, highest bioconcentration factor (BCF) in roots (0-9.570), and higher (P0.05) metal concentrations in the crops of southern and middle areas. The calculated regional soil-environmental quality criteria for Anhui province provided a new insight on developing regional soil-environmental quality criteria, which varied with different Anhui regions, and were ≥0.13-times lower than the screening values, except for Cd in the southern rape soil (0.351 mg/kg), but were generally higher for rape soils, except for Zn and As.
- Published
- 2021
13. Machine learning in the identification, prediction and exploration of environmental toxicology: Challenges and perspectives
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Xiaotong Wu, Qixing Zhou, Li Mu, and Xiangang Hu
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Machine Learning ,Environmental Engineering ,Databases, Factual ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Ecotoxicology ,Pollution ,Waste Management and Disposal ,Algorithms ,Hazardous Substances - Abstract
Over the past few decades, data-driven machine learning (ML) has distinguished itself from hypothesis-driven studies and has recently received much attention in environmental toxicology. However, the use of ML in environmental toxicology remains in the early stages, with knowledge gaps, technical bottlenecks in data quality, high-dimensional/heterogeneous/small-sample data analysis and model interpretability, and a lack of an in-depth understanding of environmental toxicology. Given the above problems, we review the recent progress in the literature and highlight state-of-the-art toxicological studies using ML (such as learning and predicting toxicity in complicated biosystems and multiple-factor environmental scenarios of long-term and large-scale pollution). Beyond predicting simple biological endpoints by integrating untargeted omics and adverse outcome pathways, ML development should focus on revealing toxicological mechanisms. The integration of data-driven ML with other methods (e.g., omics analysis and adverse outcome pathway frameworks) endows ML with widely promising application in revealing toxicological mechanisms. High-quality databases and interpretable algorithms are urgently needed for toxicology and environmental science. Addressing the core issues and future challenges for ML in this review may narrow the knowledge gap between environmental toxicity and computational science and facilitate the control of environmental risk in the future.
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- 2022
14. Impact of sulfhydryl ligands on the transformation of silver ions by molybdenum disulfide and their combined toxicity to freshwater algae
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Wei, Zou, Zhenzhen, Liu, Jiayi, Chen, Xingli, Zhang, Caixia, Jin, Guoqing, Zhang, Zhiguo, Cao, Kai, Jiang, and Qixing, Zhou
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Ions ,Molybdenum ,Silver ,Environmental Engineering ,Health, Toxicology and Mutagenesis ,Metal Nanoparticles ,Fresh Water ,Ligands ,Pollution ,Environmental Chemistry ,Disulfides ,Sulfhydryl Compounds ,Waste Management and Disposal ,Ecosystem - Abstract
The transformation of silver ions (Ag
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- 2022
15. Efficient decolorization of azo dye wastewater with polyaniline/graphene modified anode in microbial electrochemical systems
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Xin Wang, Qixing Zhou, Yuxuan Wan, Tong Gao, Ruixiang Li, Hangming Pu, Tian Li, Runtong Li, Xiaolin Zhang, and Xueyi Liu
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Environmental Engineering ,Aniline Compounds ,Health, Toxicology and Mutagenesis ,Wastewater ,Electrochemistry ,Pollution ,Redox ,Anode ,Congo red ,chemistry.chemical_compound ,Electron transfer ,chemistry ,Polyaniline ,Electrode ,Environmental Chemistry ,Graphite ,Coloring Agents ,Waste Management and Disposal ,Azo Compounds ,Electrodes ,Nuclear chemistry - Abstract
Azo dye pollution has become a worldwide issue, and the current treatment methods can hardly meet the expected emission standards. Microbial electrochemical systems (MESs) show promising applications for decolorization, but their performance critically depends on the microorganisms. Electrode modification is an interesting method of improving decolorization performance. However, the mechanisms of how the modification can affect microbial communities and the decolorization process remain unclear. Here, a modified anode with polyaniline (PANI) and graphene was fabricated via electro-deposition. Consequently, the highest decolorization efficiency was obtained. The Congo red (CR) decolorization rate of the MESs with the PANI/graphene-modified electrode (PG) reached 90% at 54 h. By contrast, the CR decolorization rates of the MESs with the PANI-modified electrode (P) and those of the MESs with the unmodified electrode (C) only reached 68% and 79%, respectively. Results of the microbial community analysis showed abundant Methanobrevibacter arboriphilus in PG (11%), which was 5.5 times that in C (2%) at 18 h. This phenomenon may be related to the rapid decolorization. The upregulated metabolism pathways, including arginine and proline metabolism, purine metabolism, arginine biosynthesis, and riboflavin metabolism, provided more electron shuttles and redox mediators that facilitated the extracellular electron transfer. Therefore, the PG-modified electrode facilitated the decolorization by altering certain metabolic pathways. This study can help to improve the guideline on the potential application of MESs for wastewater treatment.
- Published
- 2021
16. Applications and challenges of elemental sulfur, nanosulfur, polymeric sulfur, sulfur composites, and plasmonic nanostructures
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Yong Teng, Qixing Zhou, and Peng Gao
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Environmental Engineering ,Materials science ,0208 environmental biotechnology ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Pollution ,Sulfur ,020801 environmental engineering ,chemistry ,Ecological risk ,Plasmonic nanostructures ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
As an abundant and biologically active element, sulfur has been applied in various fields. Through the nanotechnology method, nanosulfur is synthesized with the merits of size effects. Differentiat...
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- 2019
17. Anthropogenic impacts on the biodiversity and anti-interference ability of microbial communities in lakes
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Jiwei Luo, Hui Zeng, Qixing Zhou, Xiangang Hu, Qian Qu, Shaohu Ouyang, and Yingying Wang
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Lakes ,Environmental Engineering ,Bacteria ,Anthropogenic Effects ,Microbiota ,Fungi ,Environmental Chemistry ,Biodiversity ,Pollution ,Waste Management and Disposal - Abstract
Lakes are critical for biogeochemical and ecological processes and are sensitive and vulnerable to anthropogenic disturbances, but how and to what extent human activities disturb the biodiversity in lakes remain unknown. Here, we showed the microbial diversity in 46 lakes and assessed the influence of 27 anthropogenic factors. We found that the economic level (e.g., per capita gross domestic product) was strongly negatively correlated (r = -0.97) with bacterial diversity but positively correlated (r = 0.17) with fungal diversity in lakes. The composition of the microbial community significantly changed with increasing economic level. Bacteria are more sensitive than fungi to anthropogenic impacts. Expanding the population size and increasing the economic level may promote the development of fungal diversity but inhibit bacterial diversity. Air quality, urbanization and ozone were negatively correlated with bacterial diversity, and fisheries had a negative correlation with fungal diversity. The anti-interference ability of lake microorganisms in the middle economic level zones (45,000-90,000 yuan/person) was stronger than that in high-level (90,000 yuan/person) and low-level (45,000 yuan/person) economic zones. Overall, our investigation provides national-scale evidence that changes in the microbial diversity in lakes were related to economic levels.
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- 2022
18. Extracellular polymeric substances mediate defect generation and phytotoxicity of single-layer MoS2
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Hui Zeng, Xiangang Hu, Qixing Zhou, Jiwei Luo, and Xuan Hou
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,Environmental Chemistry ,Pollution ,Waste Management and Disposal - Published
- 2022
19. Response of soil enzyme activity and soil bacterial community to PCB dissipation across different soils
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Qixing Zhou, Fen Hou, and Junjie Du
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Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Soil ,Soil pH ,Cation-exchange capacity ,Environmental Chemistry ,Soil Pollutants ,Soil Microbiology ,0105 earth and related environmental sciences ,Bacteria ,Chemistry ,Soil organic matter ,Public Health, Environmental and Occupational Health ,food and beverages ,Soil classification ,General Medicine ,General Chemistry ,Contamination ,Soil type ,Pollution ,Polychlorinated Biphenyls ,020801 environmental engineering ,Environmental chemistry ,Soil water ,Composition (visual arts) - Abstract
Soils are a repository for polychlorinated biphenyls (PCBs). A pot incubation experiment was performed with four soils (black soil, paddy soil, oasis soil, and fluvo-aquic soil) treated with Aroclor 1242 to achieve PCB concentrations of 5 mg kg−1. The soil enzyme activities of protease, phosphatase, catalase, dehydrogenase, and laccase were determined by spectrophotometry. The soil bacterial communities were investigated using Illumina sequencing analysis. The results showed that the characteristics of the test soils varied among the soil types. The fluvo-aquic soil had the greatest PCB dissipation rate (86.41%), followed by the oasis (79.31%), paddy (56.09%), and black (50.65%) soils. The soil pH, cation exchange capacity, soil organic matter content, and particle diameter played significant roles in PCB dissipation from soils. The soil type had a greater influence than PCB contamination on the soil enzyme activities and bacterial communities (alpha diversity, community structure, and composition). Among the four soils, the bacterial communities of the fluvo-aquic soil were the most susceptible to PCB contamination. However, the bacterial communities of the black soil were not changed by PCB contamination.
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- 2021
20. Nanotoxicological effects and transcriptome mechanisms of wheat (Triticum aestivum L.) under stress of polystyrene nanoplastics
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Yuebing Sun, Shuzhen Men, Tianzhi Yang, Qixing Zhou, Jiapan Lian, Jiani Wu, Weitao Liu, Aurang Zeb, and Lena Q. Ma
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Environmental Engineering ,Metal ion transport ,Microplastics ,Health, Toxicology and Mutagenesis ,Genes, Plant ,Transcriptome ,Gene Expression Regulation, Plant ,Gene expression ,Environmental Chemistry ,KEGG ,Waste Management and Disposal ,Gene ,Triticum ,Amino acid synthesis ,chemistry.chemical_classification ,biology ,Gene Expression Profiling ,food and beverages ,biology.organism_classification ,Pollution ,Cell biology ,chemistry ,Polystyrenes ,Plant hormone ,Signal transduction - Abstract
At present, the uptake and accumulation of nanoplastics by plants have raised particular concerns. However, molecular mechanisms underlying nanoplastic phytotoxicity are still vague and insufficient. To address this scientific gap, we analyzed the transcriptome response of hydroponically grown wheat (Triticum aestivum L.) to polystyrene nanoplastics (PSNPs) (100 nm) by integrating the differentially expressed gene analysis (DEGA) and the weighted gene correlation network analysis (WGCNA). PSNPs could significantly shape the gene expression patterns of wheat in a tissue-specific manner. Four candidate modules and corresponding hub genes associated with plant traits were identified using WGCNA. PSNPs significantly altered carbon metabolism, amino acid biosynthesis, mitogen-activated protein kinase (MAPK) signaling pathway-plant, plant hormone signal transduction, and plant-pathogen interaction Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. In addition, some Gene Ontology (GO) terms associated with the metal ion transport were further screened. These findings shed new light on the phytotoxic mechanism and environmental implication behind the interaction of nanoplastics and crop plants, and advance our understanding of the potential adverse effect induced by the presence of nanoplastics in agricultural systems.
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- 2022
21. Environmental decomposition and remodeled phytotoxicity of framework-based nanomaterials
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Xiangang Hu, Qixing Zhou, Dandan Li, Jiwei Luo, Hui Zeng, and Li Mu
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Environmental Engineering ,Chemistry ,Health, Toxicology and Mutagenesis ,Oxides ,Cobalt ,Pollution ,Nanostructures ,Adsorption ,Chemical engineering ,Nanotoxicology ,Zeolites ,Photocatalysis ,Environmental Chemistry ,Water treatment ,Metal-organic framework ,Photodegradation ,Waste Management and Disposal ,Dissolution ,Metal-Organic Frameworks ,Zeolitic imidazolate framework - Abstract
Zeolitic imidazole frameworks (ZIFs) have attracted a considerable amount of attention for use in environmental applications (e.g., pollutant adsorption and photocatalysis in water treatments). The environmental stability and toxicity of ZIFs are key prerequisites for their practical applications, but information about these factors is largely lacking. The present work finds that pristine ZIFs (ZIF-8 and ZIF-67) photodegrade from frame structures into two-dimensional nanosheets and are oxidized to zinc carbonate (ZIF-8) and Co3O4 (ZIF-67) under visible-light irradiation. The photoinduced electrons, holes and free radicals promote dissolution of the metal cores and organic ligands, leading to collapse of the frame structure. The photodegradation of ZIF-8 alleviates developmental inhibition, oxidative stress, plasmolysis, and photosynthetic toxicity, while the photodegradation of ZIF-67 aggravates nanotoxicity. The integration of metabolomics and transcriptomics analysis reveals that unsaturated fatty acid biosynthesis and metal ion-binding transcription contribute to the altered toxicity of ZIF photodegradation. These findings highlight the roles of photodegradation in structural transformation and alteration of the toxicity of ZIFs, alarming the study of pristine metal-organic frameworks (MOFs).
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- 2022
22. A highly sensitive bioelectrochemical toxicity sensor and its evaluation using immediate current attenuation
- Author
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Jingkun An, Tian Li, Lean Zhou, Qixing Zhou, Chengmei Liao, Lili Tian, Nan Li, and Xin Wang
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Environmental Engineering ,010504 meteorology & atmospheric sciences ,Attenuation ,Microbiota ,Formaldehyde ,Analytical chemistry ,Substrate (chemistry) ,Water ,010501 environmental sciences ,Acetates ,Electrochemistry ,01 natural sciences ,Pollution ,Highly sensitive ,chemistry.chemical_compound ,chemistry ,Biofilms ,Toxicity ,Environmental Chemistry ,Current (fluid) ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Toxicant - Abstract
Electroactive biofilm (EAB) sensor had shown great potential in the field of early warning of toxicants in water because of the low-cost and broad-spectrum. However, the traditional calculation of sensitivity strongly relied on the time and concentration gradient which weakened time-efficiency of the sensor. Moreover, the sensitivity could be further improved to respond trace concentrations. Here EAB sensors with different substrate concentrations were formed to respond different concentrations formaldehyde ranging from 1 ppm to 50 ppm and immediate current attenuation (ICA) was induced to evaluate the sensitivity. The ICA (~70 s) exhibited a shorter time than that calculated by calculable sensitivity (CS) and current attenuation (CA), which not only achieved the response of trace concentration but also improved the time-efficiency of the sensor. The EAB formed with 0.1 g/L acetate (EAB-0.1) had a 380% higher sensitivity than that formed with 1.0 g/L acetate (EAB-1.0), leading to a significant electrochemical toxicity response to 1 ppm of formaldehyde. The results of electrochemical response coefficient confirmed that EAB-0.1 was 1.5–6.3 times of that formed with acetate from 0.2 to 1.0 g/L, which was related with microbial community and component of EAB as described in our previous study. Our findings demonstrated that calculation of sensitivity could be optimized to reflect time-efficiency and EAB with limit acetate could be applied in trace toxicant detection.
- Published
- 2020
23. Simultaneous removal and high tolerance of norfloxacin with electricity generation in microbial fuel cell and its antibiotic resistance genes quantification
- Author
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Shengnan Li, Fengxiang Li, Qixing Zhou, and Brim Stevy Ondon
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0106 biological sciences ,Environmental Engineering ,Microbial fuel cell ,Bioelectric Energy Sources ,Bioengineering ,010501 environmental sciences ,Wastewater ,01 natural sciences ,Electricity ,010608 biotechnology ,medicine ,Waste Management and Disposal ,Electrodes ,Norfloxacin ,0105 earth and related environmental sciences ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Drug Resistance, Microbial ,General Medicine ,biology.organism_classification ,Pulp and paper industry ,Anti-Bacterial Agents ,Electricity generation ,Degradation (geology) ,Sewage treatment ,Bacteria ,Antibiotic resistance genes ,medicine.drug - Abstract
Norfloxacin (NFLX) is a synthetic antibiotic widely used in the treatment of infectious diseases. In this work, the performance of microbial fuel cells (MFCs) toward NFLX degradation, electricity production and the antibiotics resistances genes (ARGs) generation was investigated. NFLX degradation efficiency and COD removal reached 65.5% and 94.5% respectively. The increase in NFLX concentration (128 mg/L) had no significant influence on NFLX degradation efficiency, COD removal and MFCs voltage output while the electricity was successfully generated. The quantitative polymerase chain reaction (qPCR) indicated low absolute abundances of ARGs (mdtk, mdtm, and pmra) compared with the traditional wastewater treatment plants (WWTPs). Anodic bacteria can survive in the presence of high NFLX concentration and sustain its degradation and electricity production. In terms of NFLX degradation, COD removal, diminished ARGs generation and simultaneous energy production, MFC seems to be a promising technology for antibiotics wastewater treatment with a potential to overcome the ARGs challenge.
- Published
- 2019
24. Transesterification of para-hydroxybenzoic acid esters (parabens) in the activated sludge
- Author
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Qixing Zhou, Tianzhen Liu, Lei Wang, and Hongwen Sun
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021110 strategic, defence & security studies ,Hydroxybenzoic acid ,Environmental Engineering ,Ethanol ,biology ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,02 engineering and technology ,Transesterification ,010501 environmental sciences ,01 natural sciences ,Pollution ,Paraben ,chemistry.chemical_compound ,Hydrolysis ,Activated sludge ,chemistry ,biology.protein ,Environmental Chemistry ,Organic chemistry ,Methanol ,Lipase ,Waste Management and Disposal ,0105 earth and related environmental sciences - Abstract
Hydrolysis is generally considered as the main pathway for the degradation of ester-type pollutants in aquatic environments. In this study, we found that when methanol or ethanol presented as the external carbon in the activated sludge, transesterification is very important for the degradation of para-hydroxybenzoic acid esters (parabens). In the activated sludge solutions with 1% methanol added, contribution of transesterification to the degradation of the propyl substituted paraben (PrP) and ethyl substituted paraben (EtP) accounted for 46% and 83%, respectively, in the early stage of the reaction. This indicates that in aquatic environments with alcohols presence, parabens prefer to form small molecule homologues than hydrolysis to acid. The predominant transesterification in the activated sludge is related to enzyme preference. Amano lipase from Pseudomonas fluorescens was verified to catalyze hydrolysis and transesterification of parabens, while the latter was dominant in water solution with 1% methanol or ethanol. Considering the common application of small molecular alcohols as the external carbon sources in wastewater treatment plants, transesterification might be an important pathway for the degradation of parabens pollutants in these engineering aquatic environments.
- Published
- 2018
25. Characterization and toxicity of nanoscale fragments in wastewater treatment plant effluent
- Author
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Xiaowei Liu, Qixing Zhou, Chaoxiu Ren, Weilu Kang, Tong Wang, Xiaokang Li, Xiangang Hu, and Li Mu
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Environmental Engineering ,chemistry.chemical_element ,02 engineering and technology ,Wastewater ,010501 environmental sciences ,Waste Disposal, Fluid ,01 natural sciences ,Environmental Chemistry ,Waste Management and Disposal ,Effluent ,0105 earth and related environmental sciences ,Nanosheet ,Contamination ,021001 nanoscience & nanotechnology ,Pollution ,chemistry ,Nanotoxicology ,Environmental chemistry ,Nanoparticles ,Sewage treatment ,Phytotoxicity ,0210 nano-technology ,Carbon ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Much attention has been paid to extracting and isolating specific and well-known nanoparticles (especially for engineered nanomaterials) from complex environmental matrices. However, such research may not provide global information on actual contamination because nanoscale fragments exist as mixtures of various elements and matrices in the real environment. The present work first isolated and characterized nanoscale fragments in effluents from municipal wastewater treatment plants (WWTPs). The nanoscale fragments were found to be composed of 70–85% carbon and low amounts of oxygen, heavy metals and other elements and exhibited nanosheet topographies (approximately 0.87–1.31 nm thickness and 68–187 nm lateral length). Because the isolated nanoscale fragments were mixtures rather than one specific type of nanoparticle, they were present at high concentrations ranging from 0.07 to 0.55 mg/L. It was also found that the accumulation of nanoscale fragments in rice reached 0.59 mg/g under exposure to environmentally relevant concentrations, leading to marked phytotoxicity (e.g., ultrastructural damage to chloroplasts and mitochondria). Metabolic analysis revealed the toxicological mechanisms to be related to disorders of carbohydrate, amino acid and fatty acid metabolism. This study is the first to characterize the properties and analyze the toxicity of nanoscale fragments in the effluents of WWTPs. Given that WWTP effluents containing nanoscale fragments are continuously discharged to the soil, surface water and seas, nanoscale fragment materials deserve considerable attention in future work compared with the few widely studied engineered nanoparticles.
- Published
- 2018
26. Surfactants selectively reallocated the bacterial distribution in soil bioelectrochemical remediation of petroleum hydrocarbons
- Author
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Xiaojing Li, Xin Wang, Qian Zhao, Yongtao Li, and Qixing Zhou
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DNA, Bacterial ,Environmental Engineering ,Microbial fuel cell ,Bioelectric Energy Sources ,Firmicutes ,Environmental remediation ,Health, Toxicology and Mutagenesis ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Microbiology ,Actinobacteria ,Clostridia ,Surface-Active Agents ,Bioremediation ,Soil Pollutants ,Environmental Chemistry ,Waste Management and Disposal ,Soil Microbiology ,0105 earth and related environmental sciences ,Bacteria ,biology ,Electrochemical Techniques ,021001 nanoscience & nanotechnology ,biology.organism_classification ,Pollution ,Hydrocarbons ,Biodegradation, Environmental ,Petroleum ,Environmental chemistry ,Proteobacteria ,Alcaligenes ,0210 nano-technology - Abstract
Soil contaminated by aged petroleum hydrocarbons is faced with scarcity of electron acceptors, low activity of functional microbes and inefficient electron transfer, which hinder the bioremediation application. The soil microbial fuel cell (MFC) simultaneously solves these problems with bioelectricity production. In this study, five types of surfactants were introduced to enhance the bioavailability of aged petroleum hydrocarbon in soils. The ampholytic surfactant (lecithos) was optimal due to the highest bioelectricity generation (0.321C d −1 g −1 ) and promoted hydrocarbon degradation (328%), while the nonionic (glyceryl monostearate) and cationic (cetyltrimethylammonium bromide) surfactants were inefficient. The surfactants induced a special microbial enrichment affiliated with Proteobacteria , Firmicutes , Bacteroidetes , Actinobacteria , Chloroflexi , Planctomycetes and Acidobacteria (93%–99% of total) in soil MFCs. The anionic surfactant (sodium dodecyl sulfate) exhibited the strongest selectivity, and α- proteobacteria and γ - proteobacteria abundances decreased while Clostridia increased, much like the result obtained with the biosurfactant β -cyclodextrin. Furthermore, Bacillus abundance was increased in connected soil MFCs, except addition of lecithos in which Clostridium increased to 14.88% from 3.61% in the control. The high correlations among Bacillus , Phenylobacterium , Solibacillus (0.9162–0.9577) and among Alcaligenes , Dysgonomonas , Sedimentibacter (0.9538–0.9966) indicated a metabolic network of microorganisms in the soil bioelectrochemical remediation system.
- Published
- 2018
27. Impact of algal extracellular polymeric substances on the environmental fate and risk of molybdenum disulfide in aqueous media
- Author
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Zepeng Wan, Wei Zou, Chenxu Zhao, Xingli Zhang, Guoqing Zhang, and Qixing Zhou
- Subjects
Molybdenum ,chemistry.chemical_classification ,Environmental Engineering ,Aqueous solution ,Extracellular Polymeric Substance Matrix ,Ecological Modeling ,Reactive intermediate ,Polysaccharide ,Pollution ,chemistry.chemical_compound ,Extracellular polymeric substance ,chemistry ,Toxicity ,Biophysics ,Animals ,Water treatment ,Disulfides ,Waste Management and Disposal ,Molybdenum disulfide ,Dissolution ,Zebrafish ,Water Science and Technology ,Civil and Structural Engineering - Abstract
Molybdenum disulfide (MoS2) poses great potential in water treatment as a popular transition metal dichalcogenide, arousing considerable concern regarding its fates and risk in aquatic environments. This study revealed that the interplay with extracellular polymeric substances (EPS) of freshwater algae significantly changed the properties and toxicity of MoS2 to aquatic fish. The predominant binding of aromatic compounds, polysaccharides, and carboxyl-rich proteins in EPS on the 1T polymorph of MoS2 via hydrophilic effects and the preferential adsorption of carboxylic groups contributed to morphological alterations, structural disorders (band gap and phase alterations), and the attenuated aggregation of MoS2 in aqueous solutions. Electron charge transfer and n-π* interactions with EPS decreased the catalytic activity of MoS2 by inhibiting its capability of generating reactive intermediates. The dissolution of MoS2 slowed down after interacting with EPS (from 0.089 to 0.045 mg/L per day) owing to rapid initial oxidation (i.e., forming Mo-O bond) and carbon grafting. Notably, the morphological and structural alterations after EPS binding alleviated the toxicity (e.g., malformation and oxidative stress) of MoS2 to infantile zebrafish. Our findings provide insights into the environmental fate and risk of MoS2 by ubiquitous EPS in natural waters, serving as valuable information while developing water treatment processes accordingly.
- Published
- 2021
28. Microbial Fuel Cells for Organic-Contaminated Soil Remedial Applications: A Review
- Author
-
Liping Weng, Xiaojing Li, Yongtao Li, Qixing Zhou, and Xin Wang
- Subjects
Bodemscheikunde en Chemische Bodemkwaliteit ,microbial fuel cells ,Microbial fuel cell ,biocatalysis ,Environmental remediation ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Soil conductivity ,environmental chemistry ,0105 earth and related environmental sciences ,Electrode material ,WIMEK ,Waste management ,Environmental engineering ,soil remediation ,021001 nanoscience & nanotechnology ,Soil remediation ,Soil contamination ,General Energy ,electrochemistry ,Wastewater ,Soil water ,Environmental science ,0210 nano-technology ,Soil Chemistry and Chemical Soil Quality - Abstract
Efficient noninvasive techniques are desired for repairing organic-contaminated soils. Bioelectrochemical technology, especially microbial fuel cells (MFCs), has been widely used to promote a polluted environmental remediation approach, and applications include wastewater, sludge, sediment, and soil remediation. Soil MFC remediation has been of significant concern in recent years, and thus, several aspects, including reactor configuration, electrode materials, soil conductivity, mass transfer, and microbial activity, are reviewed. Recent studies and key issues of soil MFCs and perspectives of organic-contamination remedial application are summarized, with the aim of assisting environmental scholars and engineers to gain a comprehensive understanding of MFC remediation. Insights are also offered on how to extend applications to help soil MFC remediation technology to advance and be applied in the future on a large scale.
- Published
- 2017
29. Adsorption behavior of Sudan I-IV on a coastal soil and their forecasted biogeochemical cycles
- Author
-
Yong Teng and Qixing Zhou
- Subjects
Sudan I ,Biogeochemical cycle ,Health, Toxicology and Mutagenesis ,Environmental engineering ,Naphthols ,02 engineering and technology ,General Medicine ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,01 natural sciences ,Pollution ,Sudan III ,Soil ,chemistry.chemical_compound ,Adsorption ,chemistry ,Environmental chemistry ,Soil water ,Sudan II ,Environmental Chemistry ,Environmental science ,0210 nano-technology ,Azo Compounds ,0105 earth and related environmental sciences - Abstract
Sudan I-IV as synthetic azo dyes have been concerned worldwide and ever caused a panic on food safety because of illegal addition into foodstuffs. In the past decades, various methods are being developed to identify and determine Sudan dyes in foodstuffs. However, relevant studies about their biogeochemical behaviors and potential environmental effects are rarely reported, although it is of great importance and necessity accounting for their potential environmental contamination from various sources. In this work, the experimental studies on adsorption behavior of Sudan I-IV acting on soil (10, 25, 50, 75, and 100 mg/L) were carried out, and their transport in soil compartments and between soil-water, and air-soil interfaces were discussed. Results showed that the amount of Sudan I-IV adsorbed on soil increased accordingly with the increasing concentration of Sudan dyes in aqueous solution, and Sudan II and IV were more likely adsorbed on the tested soils than Sudan I and III based on their maximum adsorption amount. However, for Sudan I, III, and IV, in some high concentrations (under the treatment of 75 mg/L for Sudan III, 100 mg/L for Sudan I and IV), the adsorption was significantly increased, and then came back to the "normal" level (under the treatment of 100 mg/L for Sudan III). It is expected that relevant researches on their biogeochemical behaviors in soil compartments, and between soil-water and air-soil interfaces would be concerned and addressed.
- Published
- 2017
30. Vegetation alleviate the negative effects of graphene oxide on benzo[a]pyrene dissipation and the associated soil bacterial community
- Author
-
Qixing Zhou, Yongning Wu, Guifeng Li, Jianhu Wu, Guoqin Li, and Junjie Du
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,0208 environmental biotechnology ,Oxide ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Soil ,medicine ,Benzo(a)pyrene ,Environmental Chemistry ,Soil Pollutants ,Polycyclic Aromatic Hydrocarbons ,Soil Microbiology ,0105 earth and related environmental sciences ,Pollutant ,Bacteria ,Public Health, Environmental and Occupational Health ,General Medicine ,General Chemistry ,Pollution ,Soil contamination ,020801 environmental engineering ,Phytoremediation ,Biodegradation, Environmental ,chemistry ,Environmental chemistry ,Pyrene ,Graphite ,Species richness ,medicine.symptom ,Vegetation (pathology) - Abstract
Graphene oxide (GO) will enter the soil environment in increasing amounts. The effects of GO on the dissipation of benzo[a]pyrene (B[a]P) from contaminated soil and their phytoremediation system have been explored in this study. B[a]P is a ubiquitous soil pollutant used as a representative indicator of polycyclic aromatic hydrocarbons. A pot experiment was performed to investigate the effects of GO or/and vegetation (Tagetes patula) on B[a]P dissipation and the associated bacterial communities in soil. The bacterial communities in soil were investigated by Illumina sequencing analysis. The presence of vegetation significantly enhanced the dissipation of B[a]P from soil. The addition of GO (100 mg/kg) significantly decreased the B[a]P dissipation. When vegetation and GO coexisted, the inhibition effects of GO on B[a]P dissipation were alleviated by vegetation. Compared with the control treatment, the presence of GO or vegetation had no significant effects on the richness and diversity of bacterial communities in B[a]P-contaminated soil. Compared with the presence of only vegetation, the richness and diversity all significantly decreased when vegetation and GO coexisted. And, vegetation had a greater influence on the bacterial community composition than GO. Vegetation alleviated the inhibition effects of GO on B[a]P dissipation and had a greater influence on the associated bacterial communities than GO. This work helps to understand the interactive effects of GO and vegetation on B[a]P dissipation and the associated bacterial communities in contaminated soil.
- Published
- 2019
31. Widely distributed nanocolloids in water regulate the fate and risk of graphene oxide
- Author
-
Qixing Zhou, Kaiwen Li, Shaohu Ouyang, and Xiangang Hu
- Subjects
Environmental Engineering ,0208 environmental biotechnology ,Engineered nanomaterials ,Oxide ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,law.invention ,Nanomaterials ,chemistry.chemical_compound ,Environmental risk ,law ,Animals ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,Chemistry ,Graphene ,Ecological Modeling ,Natural water ,Water ,Oxides ,Pollution ,020801 environmental engineering ,Nanostructures ,Biophysics ,Zebrafish embryo ,Graphite ,Adsorption - Abstract
The environmental behaviors and risks associated with graphene oxide (GO, a popular 2D nanomaterial) have attracted considerable attention. GO released to aquatic systems will most likely interact with ubiquitous nanocolloids (Nc) in surface water. However, the effects of Nc on the fate and risk of GO remain largely unknown in water. Herein, the binding of Nc onto GO was investigated via electron microscopy, electron paramagnetic resonance, 2D correlation spectroscopy and biolayer interferometry. The results revealed that electron charge transfers, hydrophilic effects and π-π stacking contributed to a strong affinity (KD = 5.6 nM) and high adsorption capacity (159.8 mg/g) of Nc onto the GO surface. Moreover, GO nanosheets transformed to a scroll morphology or multiple GO particles bridging by Nc, which remarkably reduced the aggregation and sedimentation rates after binding with Nc. Interestingly, co-exposure with Nc greatly alleviated the toxicity (e.g., tail malformation, yolk sac edema and oxidative stress) of GO to zebrafish embryos. Morphological and structural alterations of GO after binding to Nc contributed to the mechanisms for the antagonistic effects on the zebrafish embryos toxicity. The present work provides insights into the environmental fate and risk of GO by ubiquitous Nc in natural water.
- Published
- 2019
32. Graphene oxide quantum dots stimulate indigenous bacteria to remove oil contamination
- Author
-
Li Mu, Yujie Zhao, Xiangang Hu, Qixing Zhou, and Xiaowei Liu
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,0211 other engineering and technologies ,Bacillus cereus ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,chemistry.chemical_compound ,Bioremediation ,Extracellular polymeric substance ,Quantum Dots ,Environmental Chemistry ,Petroleum Pollution ,Waste Management and Disposal ,Environmental Restoration and Remediation ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,021110 strategic, defence & security studies ,biology ,Bacteria ,Biofilm ,Contamination ,biology.organism_classification ,Pollution ,chemistry ,Biochemistry ,Graphite ,Aromatic hydrocarbon ,Xenobiotic - Abstract
Oil spills occur frequently worldwide, resulting in severe damage to water and to human health. Polycyclic aromatic hydrocarbons (PAHs) are the primary toxic components in oil contamination. PAH-degrading microbes have attracted significant attention, but difficulty in their selection and proliferation limits their applications. Graphene oxide quantum dots (GOQDs) improve the proliferation of an indigenous PAH-degrading strain, Bacillus cereus, more effectively than large graphene oxide flakes. Bacillus cereus can metabolize a variety of xenobiotic aromatic compounds as carbon sources and is used in bioremediation. GOQDs contain a variety of aromatic hydrocarbon structures, explaining why the bacteria achieve strong tolerance to PAHs. GOQD-activated cytokinesis increases the secretion of substances important for biofilm formation (extracellular polymeric substances), which further accelerates PAH removal. Proteomic analysis reveals the molecular mechanisms underlying GOQD-induced microbial proliferation. GOQDs induce the overexpression of microbial divisomal proteins associated with division initiation, DNA replication and peptidoglycan hydrolysis/synthesis. Importantly, PAH removal mediated by GOQD-treated Bacillus cereus does not require the addition of GOQDs. The effects of GOQDs on a strain persist for at least 20 generations, suggesting their possible use in low-cost applications. This work proposes a strategy to remove oil contamination using an indigenous bacterial system enhanced by nanomaterials.
- Published
- 2018
33. Leaching of graphene oxide nanosheets in simulated soil and their influences on microbial communities
- Author
-
Xiangang Hu, Tong Wang, Qixing Zhou, and Dandan Li
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,Soil biology ,0211 other engineering and technologies ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Soil ,chemistry.chemical_compound ,Adsorption ,Environmental Chemistry ,Leachate ,Leaching (agriculture) ,Waste Management and Disposal ,Soil Microbiology ,0105 earth and related environmental sciences ,Nanosheet ,021110 strategic, defence & security studies ,Chemistry ,Microbiota ,Pollution ,Environmental chemistry ,Soil horizon ,Graphite ,Carbon - Abstract
With the wide use of graphene-like nanosheets, especially in agriculture, their release into the environment, it is crucial to grasp the fate of nanosheets in soil and minimum ecological risks. The present work discovered that leaching and migration of nanosheets (rGO) in soil is affected by soil porosity and adsorption processes. And the contents of rGO−Pd in soil layers and leachate increased and then decreased with the decreased of soil porosity. Moreover, physicochemical properties of rGO−Pd nanosheets changed by leaching processes, especially the changes of morphology, thickness and oxygen functional groups. Leaching of rGO−Pd also interfered the soil microbial homeostasis accompanied by the increase of microbial species richness and community diversity. In addition, rGO−Pd altered the usage of carbon sources by edaphon. The utilization of carbon sources by soil microbes, such as polymers, sugars, phenolic acids, carboxylic acids, amino acids, and amines, was also reduced by nanosheets. These findings provide new insights into environmental behaviors of nanomaterials and nanogeochemistry.
- Published
- 2021
34. Widespread Occurrence of Benzotriazoles and Benzothiazoles in Tap Water: Influencing Factors and Contribution to Human Exposure
- Author
-
Junjie Zhang, Qixing Zhou, Lei Wang, and Hongwen Sun
- Subjects
China ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Tap water ,Humans ,Environmental Chemistry ,Benzothiazoles ,Cities ,Groundwater ,Effluent ,0105 earth and related environmental sciences ,Drinking Water ,010401 analytical chemistry ,Environmental engineering ,Environmental Exposure ,General Chemistry ,Environmental exposure ,Contamination ,0104 chemical sciences ,Human exposure ,Environmental chemistry ,Environmental science ,Sewage treatment ,Surface water ,Water Pollutants, Chemical - Abstract
Despite the frequent detection of benzotriazoles (BTRs) and benzothiazoles (BTHs) in groundwater and surface-water environments, knowledge on their occurrence and profile in tap water is still scarce. This study demonstrates widespread occurrence of these compounds in tap water from 51 major cities in China, which have ranges of
- Published
- 2016
35. Sand amendment enhances bioelectrochemical remediation of petroleum hydrocarbon contaminated soil
- Author
-
Nan Li, Xin Wang, Yueyong Zhang, Zhiyong Jason Ren, Xiaojing Li, and Qixing Zhou
- Subjects
Environmental Engineering ,Environmental remediation ,Health, Toxicology and Mutagenesis ,Amendment ,Alcanivoraceae ,complex mixtures ,Soil ,Soil Pollutants ,Environmental Chemistry ,Polycyclic Aromatic Hydrocarbons ,Electrodes ,Soil Microbiology ,chemistry.chemical_classification ,biology ,Denaturing Gradient Gel Electrophoresis ,Chemistry ,Public Health, Environmental and Occupational Health ,Electrochemical Techniques ,General Medicine ,General Chemistry ,Silicon Dioxide ,biology.organism_classification ,Pollution ,Soil contamination ,Biodegradation, Environmental ,Petroleum ,Hydrocarbon ,Environmental chemistry ,Soil water ,Alcanivorax ,Soil microbiology - Abstract
Bioelectrochemical system is an emerging technology for the remediation of soils contaminated by petroleum hydrocarbons. However, performance of such systems can be limited by the inefficient mass transport in soil. Here we report a new method of sand amendment, which significantly increases both oxygen and proton transports, resulting to increased soil porosity (from 44.5% to 51.3%), decreased Ohmic resistance (by 46%), and increased charge output (from 2.5 to 3.5Cg(-1)soil). The degradation rates of petroleum hydrocarbons increased by up to 268% in 135d. The degradation of n-alkanes and polycyclic aromatic hydrocarbons with high molecular weight was accelerated, and denaturing gradient gel electrophoresis showed that the microbial community close to the air-cathode was substantially stimulated by the induced current, especially the hydrocarbon degrading bacteria Alcanivorax. The bioelectrochemical stimulation imposed a selective pressure on the microbial community of anodes, including that far from the cathode. These results suggested that sand amendment can be an effective approach for soil conditioning that will enhances the bioelectrochemical removal of hydrocarbons in contaminated soils.
- Published
- 2015
36. Graphene oxide nanosheets mitigate the developmental toxicity of TDCIPP in zebrafish via activating the mitochondrial respiratory chain and energy metabolism
- Author
-
Wei Zou, Shaohu Ouyang, Qixing Zhou, Xingli Zhang, and Xiangang Hu
- Subjects
Environmental Engineering ,010504 meteorology & atmospheric sciences ,Developmental toxicity ,010501 environmental sciences ,Carbohydrate metabolism ,01 natural sciences ,Electron Transport ,Organophosphorus Compounds ,Metabolomics ,Water environment ,Animals ,Environmental Chemistry ,Waste Management and Disposal ,Zebrafish ,Ecosystem ,Flame Retardants ,0105 earth and related environmental sciences ,biology ,Chemistry ,biology.organism_classification ,Pollution ,Organophosphates ,Cell biology ,Citric acid cycle ,Mitochondrial respiratory chain ,Nanotoxicology ,Graphite - Abstract
Graphene oxide (GO), a novel two-dimension carbon nanomaterial, has showed tremendous potential for utilization in intelligent manufacturing and environmental protection. In parallel, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) is widely distributed in the water environment and represents a great threat to ecosystem health. However, the related knowledge remained absent regarding the impact of GO on the biological risks of TDCIPP. Herein, GO significantly reduced the mortality and malformation rates of zebrafish induced by TDCIPP maximumly by 28.6% and 41.8%, respectively. Decreased mitochondrial respiratory chain (MRC) enzyme and ATP activity induced by TDCIPP were mitigated by GO. Integrating proteomics and metabolomics revealed TDCIPP obviously induced the downregulation of the proteins and metabolites involved in the cytoskeleton, mitochondrial function, carbohydrate and amino acid metabolism, and the TCA cycle, but the alterations were attenuated by GO. GO primarily promoted MRC activity, carbohydrate metabolism, and fatty acid β-oxidation, thus activating the energy metabolism of zebrafish and leading to antagonistic effects on the developmental toxicity of TDCIPP. These results provide a novel view on the co-exposure of GO with other pollutants and promote the reconsideration of the environmental risks of GO.
- Published
- 2020
37. Acetate limitation selects Geobacter from mixed inoculum and reduces polysaccharide in electroactive biofilm
- Author
-
Yuqing Yan, Jingkun An, Chengmei Liao, Lili Wan, Lean Zhou, Nan Li, Qixing Zhou, Xin Wang, and Tian Li
- Subjects
Environmental Engineering ,Bioelectric Energy Sources ,Microorganism ,0208 environmental biotechnology ,Biomass ,02 engineering and technology ,Acetates ,010501 environmental sciences ,Polysaccharide ,01 natural sciences ,Polysaccharides ,Bioenergy ,Electrodes ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Civil and Structural Engineering ,chemistry.chemical_classification ,biology ,Chemistry ,Ecological Modeling ,Biofilm ,biology.organism_classification ,Pollution ,Substrate concentration ,020801 environmental engineering ,Chemical engineering ,Microbial population biology ,Biofilms ,Geobacter - Abstract
Bioelectrochemical systems (BESs) are widely investigated as a promising technology to recover bioenergy or synthesize value-added products from wastewaters. The performance of BES depends on the activity of electroactive biofilm (EAB). As the core of BES, it is still unclear how the EAB is formed from mixed inoculum, and how exoelectrogens compete with non-exoelectrogens. Here we confirmed that microbial community composition and the morphology of EAB on the electrode including the thickness and porosity of the biofilm are critical for the performance of BES, and these properties can be simply controlled by the substrate concentration during EAB formation. The EAB formed with 0.1 g/L of acetate (EAB-0.1) exhibited a 90% higher current density than that formed with 1.0 g/L acetate (EAB-1.0). EAB-0.1 had a 50% higher electroactivity per biomass and a 20% thinner thickness than EAB-1.0, which was partly due to the 54% decrease of insulative polysaccharide in biofilm. Limited acetate also imposed a selective pressure to enrich Geobacter up to 88% compared to 72% when acetate was abundant. Our findings demonstrate that a highly active EAB can be formed by limiting substrate concentration, providing a broader understanding of the EAB formation process, the ecology of interspecies competitions and potential applications for bioenergy recovery and trace toxicant detection in the future.
- Published
- 2020
38. Microbial electro-Fenton: A promising system for antibiotics resistance genes degradation and energy generation
- Author
-
Shengnan Li, Runlei Ge, Yanwanjing Liu, Brim Stevy Ondon, Song Yang, Qixing Zhou, Fengxiang Li, Tao Hua, and Yanxia Zhai
- Subjects
Environmental Engineering ,Microbial fuel cell ,010504 meteorology & atmospheric sciences ,Bioelectric Energy Sources ,medicine.drug_class ,Antibiotics ,Erythromycin ,010501 environmental sciences ,01 natural sciences ,Antibiotic resistance ,medicine ,Environmental Chemistry ,Food science ,Waste Management and Disposal ,Gene ,0105 earth and related environmental sciences ,Chemistry ,Chemical oxygen demand ,Drug Resistance, Microbial ,Contamination ,Pollution ,Biodegradation, Environmental ,Genes, Bacterial ,Degradation (geology) ,medicine.drug - Abstract
The widespread use of antibiotics has accelerated the development of antibiotic resistance genes (ARGs), which are now recognized as emerging environmental contaminants that pose a high risk to public health. In this study, simultaneous antibiotic and ARGs removal and bioelectricity generation was explored in a microbial electro-Fenton system using erythromycin (ERY) as a model antibiotic compound. The results showed that ERY could be degraded, with an average removal efficiency of 88.73% in 48 h, and the average removal efficiency of chemical oxygen demand in the microbial electro-Fenton with 50 μg L−1 ERY reached 86.84% in 48 h, which was lower than that in the control group (89.11%). The produced ARGs were analyzed and degraded in a cathode chamber. The quantity of ermB was significantly reduced, with log removal reaching a value of 1.96. More importantly, all erm genes (ermB, ermC, ermG) showed a tendency to be degraded. Furthermore, the maximum power density obtained with respect to the electrode area was 0.193 W m−2 when ERY was added, corresponding to a current density of 0.583 A m−2 (external resistor = 1000 Ω), which was 14% larger than that of the control group (0.169 W m−2). The results of this study demonstrate the potential of microbial electro-Fenton for ERY and ARGs removal.
- Published
- 2020
39. Role of extracellular polymeric substances on the behavior and toxicity of silver nanoparticles and ions to green algae Chlorella vulgaris
- Author
-
Cuihong Chen, Qijin Geng, Huiqin Wang, Dan Li, Yimin Feng, Shimei Zheng, Zhang Cai, Qixing Zhou, and Fengxia Yang
- Subjects
Chlorophyll ,Environmental Engineering ,Silver ,010504 meteorology & atmospheric sciences ,Chlorella vulgaris ,Nanoparticle ,Metal Nanoparticles ,010501 environmental sciences ,01 natural sciences ,Silver nanoparticle ,chemistry.chemical_compound ,Extracellular polymeric substance ,Algae ,Aquatic plant ,Spectroscopy, Fourier Transform Infrared ,Environmental Chemistry ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Ions ,biology ,Extracellular Polymeric Substance Matrix ,Chlorophyll A ,fungi ,biology.organism_classification ,Pollution ,chemistry ,Green algae ,Environmental Pollutants ,Oxidation-Reduction ,Nuclear chemistry - Abstract
The effect of extracellular polymeric substances (EPS), vital organic matters and nutrient elements in the natural environment, on the behavior and toxicology of silver nanoparticles (AgNPs) and ions remains ambiguous. In this study, the role of EPS on the toxicity of AgNPs and dissolved silver ions (from AgNO3) to a green algae Chlorella vulgaris was investigated. After the removal of EPS, algae accumulated more silver, about 7.41- and 1.25-fold of those in the algae with EPS for AgNPs and AgNO3 treatments, respectively. The large amount of accumulated silver was bound to the algal cell surface for AgNPs treatment and was internalized in the algae for AgNO3 treatment, irrespective of the presence of EPS in algae. After exposure to AgNPs, the ruffles in the surfaces of algal cells were filled by AgNPs, and almost invisible. FTIR showed that for both AgNPs and AgNO3, the aldehyde groups on the cell surface were oxidized to carboxyl groups by silver ions, irrespective of the presence of EPS in algal cells, indicating that silver ions were released from the oxidization of AgNPs and reacted with algal cells. The content of chlorophyll showed that AgNPs depressed algal growth more remarkably than did AgNO3, independent of the presence of EPS in algae, suggesting that AgNPs had greater toxic effects on algae than did silver ions. The findings suggest that the barrier effect of EPS gave nanoparticles an extraordinary edge over ions, but EPS had no discerning effect on the interaction of algal cells with the silver ions released from AgNPs and AgNO3, and also on the effect of AgNPs and AgNO3 on algal growth.
- Published
- 2018
40. Sewage sludge derived biochars provoke negative effects on wheat growth related to the PTEs
- Author
-
Zhongwei Sun, Lulu Kong, Zichuan Ma, Jingze Liu, and Qixing Zhou
- Subjects
0106 biological sciences ,0303 health sciences ,Environmental Engineering ,Chemistry ,Biomedical Engineering ,Bioengineering ,01 natural sciences ,03 medical and health sciences ,Root length ,Germination ,010608 biotechnology ,Environmental chemistry ,Heating temperature ,Shoot ,Phytotoxicity ,Pyrolysis ,Incubation ,Sludge ,030304 developmental biology ,Biotechnology - Abstract
Sewage sludge biochars (SSBCs) pyrolyzed at 300, 500, and 700 °C (denoted as SS300, SS500 and SS700) were applied for 5-day incubation with wheat to investigate the phytotoxicity of biochars and the specific mechanisms. The properties of the biochars, including the contents of 6 typical potential toxic elements (PTEs) and 16 priority polycyclic aromatic hydrocarbons (PAHs), were carefully examined. SS500 had the highest concentrations of 16 PAHs, while the total content of each PTE increased with increasing heating temperature. Wheat growth was suppressed substantially when the extract of SSBCs was applied at a concentration of 2 g/35 mL, with SS700 being the most toxic. In addition, increasing the concentration of SS700 extract led to increased toxicity. Both principal component analysis (PCA) and linear correlation analysis revealed that PTEs played an important role in determining the phytotoxicity of SSBCs. For the growth of wheat, the root length was the most sensitive to SSBC, followed by the shoot length and the seed germination. This study demonstrated that the growth of plants might be inhibited in the biochar-amended soil that highly leached throughout the years. This inhibition could be alleviated by using biochars produced at lower temperatures and by reducing the amount of biochars.
- Published
- 2019
41. Bacterial community changes and antibiotic resistance gene quantification in microbial electrolysis cells during long-term sulfamethoxazole treatment
- Author
-
Fengxiang Li, Wendan Xue, and Qixing Zhou
- Subjects
0106 biological sciences ,Environmental Engineering ,Sulfamethoxazole ,medicine.drug_class ,Microorganism ,Antibiotics ,Bioengineering ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Electrolysis ,law.invention ,Microbiology ,law ,010608 biotechnology ,Microbial electrolysis cell ,medicine ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Bacteria ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Biofilm ,Drug Resistance, Microbial ,General Medicine ,biology.organism_classification ,Anti-Bacterial Agents ,Proteobacteria ,Synergistetes ,medicine.drug - Abstract
In this study, sulfamethoxazole served as the electron donor for microbial electrolysis cells. After 6 months of operation, the removal efficiencies of sulfamethoxazole in three microbial electrolysis cells were 77.60%, 87.55%, and 92.53% for a 3-day period and were directly proportional to the initial added concentrations. However, the removal efficiencies in the microbial electrolysis cells with open circuits and without microorganisms were only 51% and 8%, respectively. Higher sulfamethoxazole concentrations and sustained electrical stimulation caused faster bioelectrochemical reactions, thereby enhancing sulfamethoxazole degradation. Bacterial community analysis revealed that Proteobacteria and Synergistetes, which are the main functional phyla, proliferated with increased antibiotic concentrations. The qPCR results indicated that the copy numbers of antibiotic resistance genes and integrons in microbial electrolysis cell biofilms and effluents were distinctly lower than those in traditional biological treatment systems. Thus, the generation and dissemination of antibiotic resistance genes might be a diminished challenge in microbial electrolysis cells.
- Published
- 2019
42. Degradation mechanisms of sulfamethoxazole and its induction of bacterial community changes and antibiotic resistance genes in a microbial fuel cell
- Author
-
Qixing Zhou, Wendan Xue, and Fengxiang Li
- Subjects
0106 biological sciences ,Environmental Engineering ,Achromobacter ,Microbial fuel cell ,Sulfamethoxazole ,Bioelectric Energy Sources ,medicine.drug_class ,Antibiotics ,Bioengineering ,Portable water purification ,Wastewater ,010501 environmental sciences ,01 natural sciences ,Microbiology ,010608 biotechnology ,medicine ,Waste Management and Disposal ,0105 earth and related environmental sciences ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Pseudomonas ,Drug Resistance, Microbial ,General Medicine ,bacterial infections and mycoses ,biology.organism_classification ,Anti-Bacterial Agents ,Sewage treatment ,Alcaligenes ,medicine.drug - Abstract
In this study, more than 85.1% of sulfamethoxazole (SMX) could be degraded within 60 h. The strengthening of microbial metabolisms and the sustainment of electrical stimulation contributed to the rapid removal of SMX in microbial fuel cells (MFCs). High-performance liquid chromatography identified that SMX could be thoroughly degraded into less harmful alcohols and methane after the MFC processing. In addition, the major role of Shewanella sp. and Geobacteria sp. in power generation, and the promotion of Alcaligenes, Pseudomonas and Achromobacter in SMX degradation have been demonstrated. Moreover, this study further proved that the copy numbers of targeted antibiotic resistance genes and integrons produced in MFCs were much lower than those found in conventional wastewater treatment plants; MFCs seem to be a promising alternative to reduce antibiotics in wastewater treatment and water purification.
- Published
- 2019
43. Effect of different initial low pH conditions on biogas production, composition, and shift in the aceticlastic methanogenic population
- Author
-
Binbin Hua, Lu Chen, Qixing Zhou, Weixin Zhao, Jinhui Jeanne Huang, Salman Ali, and Ronald L. Droste
- Subjects
0106 biological sciences ,Environmental Engineering ,Population ,Bioengineering ,010501 environmental sciences ,01 natural sciences ,Acclimatization ,Methanosaeta ,Bioreactors ,Biogas ,010608 biotechnology ,Anaerobiosis ,Food science ,education ,Waste Management and Disposal ,Acetic Acid ,0105 earth and related environmental sciences ,education.field_of_study ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,General Medicine ,Methanosarcina ,Hydrogen-Ion Concentration ,biology.organism_classification ,Methanogen ,Anaerobic digestion ,Biofuels ,Composition (visual arts) ,Methane - Abstract
Anaerobic digestion (AD) reactors often encounter low pH inhibition during startup and high organic loading periods. The use of a large amount of NaOH in order to raise and buffer the low pH, is reported to be inhibitory to methanogens. In order to address this problem, we acclimatized aceticlastic methanogens to low pH. Methanogens were successfully acclimatized to initial low pH down to 3.5 in a lengthy, five months, acclimatization period. The aceticlastic methanogen, Methanothrix soehngenii which was 96.3% of the total methanogenic population at pH 4.5 and 86.75% at pH 3.5, demonstrated that they were the most tolerant aceticlastic methanogens to low pH. After acclimatization, methane yield at pH 4.5 was comparable to neutral pH. Methanosaeta maintained its dominance over Methanosarcina at an elevated level of acetate (66 mM), and a negative correlation was observed between them. There was a positive correlation between the CH4 content and pH.
- Published
- 2019
44. Assessment of soil organic contamination in a typical petrochemical industry park in China
- Author
-
Yong Teng, Yuming Chen, Xinyu Miao, and Qixing Zhou
- Subjects
China ,Soil test ,Health, Toxicology and Mutagenesis ,Soil ,chemistry.chemical_compound ,Soil Pollutants ,Environmental Chemistry ,Polycyclic Aromatic Hydrocarbons ,Environmental engineering ,Soil classification ,General Medicine ,Contamination ,Pollution ,Soil contamination ,Hydrocarbons ,Petroleum ,Petrochemical ,chemistry ,Chemical Industry ,Environmental chemistry ,Soil water ,Environmental science ,Polycyclic Hydrocarbons ,Environmental Pollution ,Environmental Monitoring - Abstract
The concentrations of total petroleum hydrocarbons (TPH), n-alkanes (n-C8 through n-C40), and 16 polycyclic aromatic hydrocarbons (PAHs) in soils were determined to assess the level of organic contamination in soils from the Da-gang Petrochemical Industry Park with several big state-run enterprises, a recent rapid flourishing park in China. The results showed that the concentration of TPH in soil was high, up to 20 ng/g-12.8478%; in particular, the content in most sites ranged from 1 to 2%. Thus, it is clear that soil environment in the Da-gang Petrochemical Industry Park has been seriously polluted by TPH according to the Nemerow pollution index method. Furthermore, the average concentration of Σ(n-C>16 through n-C34) in 30 sampling sites was above the maximum limit set for F3 under all the conditions in the Canada-wide standards for petroleum hydrocarbons (PHC CWS) with 43.33-93.33% soil samples exceeding F3 standards, and n-alkanes possessing higher concentrations were proved much abundant alkanes in this study. Besides, the predominance of even n-alkanes and lower carbon preference index (CPI) demonstrated that n-alkanes in surface soils were mainly caused by anthropogenic inputs, while the concentration of Σ16-PAHs was in the range of 1652.5-8217.3 ng/g and the BaA/(BaA + Chr) and Flu/(Flu + Pyr) ratios indicated that pyrogenic PAHs may be the dominant PAHs in most soils with the contribution of petrogenic hydrocarbons in some sites.
- Published
- 2015
45. Enhanced biodegradation of aged petroleum hydrocarbons in soils by glucose addition in microbial fuel cells
- Author
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Yueyong Zhang, Xin Wang, Xiaojing Li, Qixing Zhou, Lili Wan, Desheng Li, and Nan Li
- Subjects
Microbial fuel cell ,Environmental remediation ,General Chemical Engineering ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,complex mixtures ,01 natural sciences ,Inorganic Chemistry ,chemistry.chemical_compound ,Waste Management and Disposal ,0105 earth and related environmental sciences ,021110 strategic, defence & security studies ,biology ,Renewable Energy, Sustainability and the Environment ,Chemistry ,Organic Chemistry ,Environmental engineering ,Soil classification ,Biodegradation ,biology.organism_classification ,Pollution ,Soil contamination ,Fuel Technology ,Environmental chemistry ,Soil water ,Total petroleum hydrocarbon ,Alcanivorax ,Biotechnology - Abstract
BACKGROUND: Bioelectrochemical remediation of soils contaminated by petroleum hydrocarbons has received increasing attention as an effective approach to remove pollution with simultaneous electricity generation. RESULTS: Here, glucose was added as a co-substrate in this system. The charge output of soil microbial fuel cells (MFCs) was enhanced by 262%, and the total petroleum hydrocarbon degradation rate increased by 200%. According to the increased dehydrogenase and polyphenol oxidase activities, the exogenetic glucose substantially activated hydrocarbon degradation bacteria (such as Alcanivorax). The Shannon–Wiener Index and richness of soil microbial community decreased after glucose addition, indicating that a selective enrichment of specific communities was imposed by glucose. Correlation analysis showed the biodiversity in soil far from the cathode was mainly determined by the concentration of petroleum hydrocarbons, while that in soil close to the cathode was dominated by the current. CONCLUSION: This study demonstrated that an exogenetic carbon source enhanced the bioelectrochemically assisted degradation of aged petroleum hydrocarbons in saline soils, providing an effective approach to remove contaminations from soil in barren areas or extreme environments. © 2015 Society of Chemical Industry Supporting information may be found in the online version of this article.
- Published
- 2015
46. Biochar accelerates PAHs biodegradation in petroleum-polluted soil by biostimulation strategy
- Author
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Zhongwei Sun, Yuanyuan Gao, Lulu Kong, Qixing Zhou, and Xuyang Zhao
- Subjects
Environmental Engineering ,Health, Toxicology and Mutagenesis ,010501 environmental sciences ,01 natural sciences ,Biostimulation ,RNA, Ribosomal, 16S ,Biochar ,polycyclic compounds ,Environmental Chemistry ,Soil Pollutants ,Microbial biodegradation ,Polycyclic Aromatic Hydrocarbons ,Charcoal ,Waste Management and Disposal ,Soil Microbiology ,Triticum ,0105 earth and related environmental sciences ,Bacteria ,Chemistry ,Environmental engineering ,04 agricultural and veterinary sciences ,Biodegradation ,Pollution ,Molecular Weight ,Biodegradation, Environmental ,Petroleum ,Genes, Bacterial ,visual_art ,Environmental chemistry ,Soil water ,040103 agronomy & agriculture ,visual_art.visual_art_medium ,0401 agriculture, forestry, and fisheries ,Sawdust - Abstract
Sawdust and wheat straw biochars prepared at 300°C and 500°C were applied to petroleum-polluted soil for an 84-day incubation to estimate their effectiveness on polycyclic aromatic hydrocarbons (PAHs) removal. Biochars alone were most effective at reducing PAHs contents. However, adding biochar to soils in company with NaN3 solution resulted in a decreasing trend in terms of PAHs removal, which was even lower than treatment CK without biochar. Moreover, it was discovered by PCR-DGGE files and sequencing analysis that the predominant bacterial diversity slightly decreased but the abundance of some specific taxa, including PAHs degraders, was promoted with biochar input. These results highlighted the potential of biochar application on accelerating PAHs biodegradation, which could be attributed to the properties of biochars that benefit for making the amended soil a better habitat for microbes. The impacts of biochar preparation and pollutants nature on PAHs removal were also determined. Significant reduction in the PAHs contents was detected when adding biochar prepared at a high temperature (500°C), while the feedstocks of biochar showed little effect on PAHs removal. Due to the high hydrophobicity of aromatic rings, high-molecular weight PAHs were found much more resistant to microbial degradation in comparison with low-molecular weight PAHs.
- Published
- 2017
47. Horizontal arrangement of anodes of microbial fuel cells enhances remediation of petroleum hydrocarbon-contaminated soil
- Author
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Xiaojing Li, Yueyong Zhang, Cheng Lijuan, Lili Wan, Qixing Zhou, and Xin Wang
- Subjects
Microbial fuel cell ,Bioelectric Energy Sources ,Environmental remediation ,Health, Toxicology and Mutagenesis ,Soil ,chemistry.chemical_compound ,Soil pH ,Alkanes ,Soil Pollutants ,Environmental Chemistry ,Petroleum Pollution ,Polycyclic Aromatic Hydrocarbons ,Electrodes ,chemistry.chemical_classification ,Environmental engineering ,Soil classification ,General Medicine ,Biodegradation ,Pollution ,Soil contamination ,Hydrocarbons ,Biodegradation, Environmental ,Petroleum ,Hydrocarbon ,chemistry ,Environmental chemistry ,Total petroleum hydrocarbon ,Environmental Pollution - Abstract
With the aim of in situ bioremediation of soil contaminated by hydrocarbons, anodes arranged with two different ways (horizontal or vertical) were compared in microbial fuel cells (MFCs). Charge outputs as high as 833 and 762C were achieved in reactors with anodes horizontally arranged (HA) and vertically arranged (VA). Up to 12.5 % of the total petroleum hydrocarbon (TPH) was removed in HA after 135 days, which was 50.6 % higher than that in VA (8.3 %) and 95.3 % higher than that in the disconnected control (6.4 %). Hydrocarbon fingerprint analysis showed that the degradation rates of both alkanes and polycyclic aromatic hydrocarbons (PAHs) in HA were higher than those in VA. Lower mass transport resistance in the HA than that of the VA seems to result in more power and more TPH degradation. Soil pH was increased from 8.26 to 9.12 in HA and from 8.26 to 8.64 in VA, whereas the conductivity was decreased from 1.99 to 1.54 mS/cm in HA and from 1.99 to 1.46 mS/cm in VA accompanied with the removal of TPH. Considering both enhanced biodegradation of hydrocarbon and generation of charge in HA, the MFC with anodes horizontally arranged is a promising configuration for future applications.
- Published
- 2014
48. Engineering chlorpyrifos-degrading Stenotrophomonas sp. YC-1 for heavy metal accumulation and enhanced chlorpyrifos degradation
- Author
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Qixing Zhou, Chao Yang, Chuanling Qiao, Hong Jiang, Ping Xu, and Ruihua Liu
- Subjects
inorganic chemicals ,Environmental Engineering ,chemistry.chemical_element ,Bioengineering ,Microbiology ,chemistry.chemical_compound ,Western blot ,Metals, Heavy ,medicine ,Environmental Chemistry ,Cadmium ,biology ,medicine.diagnostic_test ,biology.organism_classification ,Pollution ,Stenotrophomonas ,Biodegradation, Environmental ,Biochemistry ,chemistry ,Environmental chemistry ,Chlorpyrifos ,Toxicity ,Degradation (geology) ,Cell fractionation ,Bacteria - Abstract
Many ecosystems are currently co-contaminated with pesticides and heavy metals, such as chlorpyrifos and cadmium. A promising strategy to remediate mixed chlorpyrifos-cadmium-contaminated sites is the use of chlorpyrifos-degrading bacteria endowed with cadmium removal capabilities. In this work, a gene coding for synthetic phytochelatins (EC20) with high cadmium-binding capacity was introduced into a chlorpyrifos-degrading bacterium, Stenotrophomonas sp. YC-1, resulting in an engineered strain with both cadmium accumulation and chlorpyrifos degradation capabilities. To improve the cadmium-binding efficiency of whole cells, EC20 was displayed on the cell surface of Stenotrophomonas sp. YC-1 using the truncated ice nucleation protein (INPNC) anchor. The surface localization of the INPNC-EC20 fusion protein was demonstrated by cell fractionation, Western blot analysis, and immunofluorescence microscopy. Expression of EC20 on the cell surface not only improved cadmium binding, but also alleviated the cellular toxicity of cadmium. As expected, the chlorpyrifos degradation rate was reduced in the presence of cadmium for cells without EC20 expression. However, expression of EC20 (higher cadmium accumulation) completely restored the level of chlorpyrifos degradation. These results demonstrated that EC20 expression not only enhanced cadmium accumulation, but also reduced the toxic effect of cadmium on chlorpyrifos degradation.
- Published
- 2014
49. Variations of mercury in the inflow and outflow of a constructed treatment wetland in south Florida, USA
- Author
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Binhe Gu, Shimei Zheng, Qixing Zhou, and Yuncong Li
- Subjects
Total organic carbon ,Environmental Engineering ,chemistry.chemical_element ,Inflow ,Management, Monitoring, Policy and Law ,Mercury (element) ,chemistry.chemical_compound ,chemistry ,Environmental chemistry ,Dissolved organic carbon ,Outflow ,Water quality ,Sulfate ,Methylmercury ,Nature and Landscape Conservation - Abstract
Variations of total mercury (THg) and methylmercury (MeHg) concentrations at the inflow and outflow of a constructed treatment wetland, Stormwater Treatment Area 2 (STA-2) in south Florida were investigated from 2000 to 2011. The linkages between inflow water quality parameters and outflow THg and MeHg concentrations were assessed. THg and MeHg concentrations at the outflow in 2001 (2.88 and 0.95 ng L −1 ) and 2002 (2.33 and 0.87 ng L −1 ) were significantly greater than those (1.14 and 0.14 ng L −1 , 1.16 and 0.12 ng L −1 , respectively) at the inflow during the same time period. This was due to dryout and rewetting which may lead to Hg release from soil and promote Hg methylation. The average concentrations (0.75 and 0.11 ng L −1 ) of THg and MeHg at the outflow from 2005 to 2011 (except 2007) were lower than those (1.00 and 0.13 ng L −1 ) at the inflow, indicating that net THg and MeHg retention occurred in STA-2 during those years, which ranged from 0.35% to 49% for THg and from 3.5% to 37% for MeHg, respectively. Stepwise regression identified several inflow water quality parameters which explained 68% and 58% of the variances in the outflow THg and MeHg concentrations from 2000 to 2011. Certain inflow quality parameters were strong predictors of the variations in outflow THg and MeHg concentrations. These parameters included sulfate, chloride, dissolved organic carbon (DOC), dissolved oxygen (DO), pH, and temperature for outflow THg; and sulfate, chloride, DOC, and DO for outflow MeHg. Inflow sulfate and DO concentrations separately exhibited significant correlations with outflow THg and MeHg concentrations only prior to 2004. The results indicate that STA-2 was a source of THg and MeHg during early years of operation and a sink for THg and MeHg when the wetland passed the initial operation period and especially as water management improved to prevent dryout from occurring. Findings from this study also underscore the important role of inflow water quality to the variations of the outflow THg and MeHg concentrations.
- Published
- 2013
50. Application of Nanoscale Zero Valent Iron Combined with Impatiens Balsamina to Remediation of E-Waste Contaminated Soils
- Author
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Yuan Yuan Gao and Qixing Zhou
- Subjects
Pollutant ,Pollution ,Zerovalent iron ,Materials science ,Environmental remediation ,media_common.quotation_subject ,General Engineering ,Environmental engineering ,Soil contamination ,Phytoremediation ,Phytotechnology ,Environmental chemistry ,Soil pH ,media_common - Abstract
E-waste contamination is of major environmental concern on a world scale, with the rapid development of electric industry. The recycling and disposal methods of e-wastes remain rudimentary, and pose a serious environmental threat and have adverse influences on human health, because toxic pollutants such as polychlorinated biphenyls (PCBs), and heavy metals are released into the environment during crude recycling. nanophytoremediation is a combined technology between nanotechnology and phytotechnology for remediation of contaminated environments. This work was aimed to investigate the tolerance and accumulation characteristics of e-waste pollution, as well as the effect of nanoscale zero valent iron (nZVI) on their phytoremediation capacity. Results showed that nZVI could facilitate the growth of plants both under clean soil and the high pollution, with increased by 30.3% and 53.5% respectively. This may be attributed to the improvement of soil quality and adjustment of soil pH by nZVI. Especially, all the nZVI adding treatments had significantly higher PCBs accumulation efficiency compared with that without addition of nZVI, thus indicating nZVI-phytroremediation would be a very promising method in the future.
- Published
- 2013
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