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Evidence linking O 3 exposure and human semen quality is limited and conflicting and the mechanism underlying the association remains unclear. Therefore, we investigated the associations between ambient O 3 exposure and sperm quality parameters and explored the mediating role of sperm mitochondrial DNA copy number (mtDNAcn) and sperm telomere length (STL) among 1068 potential sperm donors who provided 5002 repeated semen samples over approximately 90 days. We found that every 10 μg/m3 increase in O 3 exposure was associated with a decrease in STL, sperm concentration, total count, total motile sperm number, and semen volume. However, O 3 exposure was associated with increased total motility and progressive motility. The association for sperm quality parameters was stronger when exposure was measured at spermatogenesis stages I and II. For STL, the strongest association was observed when exposure was measured at spermatogenesis stage II. Additionally, we found that approximately 9% and 8% of the association between O 3 exposure and sperm concentration and count was mediated by STL, respectively. In summary, our findings suggest that O 3 pollution may affect sperm telomere length, eventually leading to reduced semen quality. [Display omitted] • O 3 exposure affects sperm count, concentration and total motile sperm count. • O 3 exposure affects the mechanism-based indicator, sperm telomere length. • Spermatogenesis stages I and II are the sensitive windows of ozone exposure. • Sperm telomere length mediates the association of ozone exposure with sperm quality. [ABSTRACT FROM AUTHOR]

In the present study, the degradation mechanisms of beta-cypermethrin and its metabolites in soil were explored through the quantitative response relationships between the degradation rates and related functional genes. We found that the degradation rate of beta-cypermethrin was rapid in unsterilized soil but not in sterilized soil, which indicated that the degradation process is microbially based. Moreover, three metabolites (3-phenoxybenzoic acid, phenol and protocatechuic acid) were detected during the degradation process and used to identify the degradation pathway and functional genes related to the degradation process. The key rate-limiting functional genes were pytH and pobA, and the relative contributions of these genes to the degradation process were examined with a path analysis. The path analysis revealed that the genes pobA and pytH had the greatest direct effects on the degradation of beta-cypermethrin (pobA), alpha-cypermethrin (pobA), theta-cypermethrin (pytH) and 3-phenoxybenzoic acid (pytH). [ABSTRACT FROM AUTHOR]

The effects of low-concentration monorhamnolipid (monoRL) on the adsorption of Pseudomonas aeruginosa ATCC 9027 grown on glucose or hexadecane to glass beads with hydrophobic or hydrophilic surfaces was investigated using batch adsorption experiments. Results showed that adsorption isotherms of the cells on both types of glass beads fitted the Freundlich equation better than the Langmuir equation. The K f of the Freundlich equation for adsorption of hexadecane-grown cell to glass beads with hydrophobic surface was remarkably higher than that for adsorption of hexadecane-grown cell to glass beads with hydrophilic surface, or glucose-grown cell to glass beads with either hydrophilic or hydrophobic surface. Furthermore, it decreased with the increasing monoRL concentration. For both groups of cells, the zeta potential was close to each other and stable with the increase of monoRL concentration. The surface hydrophobicity of hexadecane-grown cells, however, was significantly higher than that of the glucose-grown cells and it decreased with the increase of monoRL concentration. The results indicate the importance of hydrophobic interaction on adsorption of bacterial cells to surfaces and monoRL plays a role in reducing the bacterial adsorption by affecting cell surface hydrophobicity. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, reactive brilliant X-3B was used as a model compound to study the photocatalytic activity of TiO2. Experimental results showed that the adulteration of iron and silver on TiO2 could greatly improve the activity of TiO2, and the optimum adulteration amount of iron and silver was 0.1wt.% (Fe/TiO2) and 0.05wt.% (Ag/TiO2), respectively, at the adulteration range of experiments. The photocatalytic degradation kinetics of X-3B on TiO2, Fe/TiO2 and Ag/TiO2 were also studied. The results showed that the degradation of X-3B on all of them were in accordance with the Langmiur–Hinshelwood kinetics model well, and the sequence of apparent reaction rate constants k of X-3B degradation catalyzed by TiO2, Fe/TiO2 and Ag/TiO2 was Ag/TiO2>Fe/TiO2>TiO2, while adsorption equilibrium constants KA of X-3B on Fe/TiO2 and Ag/TiO2 were approximately the same, and both were greater than that of TiO2. [Copyright &y& Elsevier]

In this study, liquid culture systems containing rhamnolipid-solubilized, separate-phase, and multi-state hexadecane as the carbon source were employed for examining the effect of rhamnolipid solubilization on the bioavailability of hexadecane. Experimental results showed that the uptake of rhamnolipid-solubilized hexadecane by Pseudomonas aeruginosa ATCC 9027, a rhamnolipid producing strain, was enhanced compared to the uptake of mass hexadecane as a separate phase, indicating rhamnolipid solubilization increased the bioavailability of hexadecane for this bacterium. For Pseudomonas putida CICC 20575 which does not produce but degrade rhamnolipid, the uptake of either rhamnolipid-solubilized hexadecane or multi-state hexadecane was inhibited. The reduction of bioavailability was assumed to be the consequence of the blocking effect caused by the partition of rhamnolipid molecules at the hexadecane-water interface. The results show that how rhamnolipid solubilization changes the bioavailability of hexadecane depends on the bacterial compatibility to rhamnolipid. The study adds insight into the knowledge of biosurfactant-associated bioavailability of hydrophobic organic compounds (HOCs), and is of importance for application of biosurfactants in bioremediation of HOCs. [ABSTRACT FROM AUTHOR]

Thermal treatment can be an effective method for soil remediation, and numerical models play a crucial role in elucidating the underlying processes that affect efficacy. In this study, experiments were conducted to examine the low-temperature thermal treatment for removing n-hexane and n-octane from soil. The results showed that the removal of two alkanes followed the pseudo-first-order kinetics. Additionally, a quantitative relationship between kinetics constant and temperature was established. Based on experimental results, a simple mathematical model was presented via COMSOL Multiphysics 6.0. The processes considered in the model incorporated conductive and convective heat transfer, the vaporization latent heat, and the removal of organic contaminants which was quantified using an advection-dispersion equation combined with a pseudo-first-order kinetic. The developed model was first validated by a thermal treatment in a soil column, demonstrating conformity with the measured temperature and concentration values. Subsequently, the temporal and spatial changes in soil temperature and contaminant levels were evaluated for different heating temperatures. It was found that thermal conduction dominated heat transfer, whereas thermal convection caused by the migration of liquid water intensified when the temperature was higher than the boiling point. The completion time exhibited a correlation with the heating temperature. It was predicted that the time required to achieve a 90% removal efficiency could be shortened from 14 h to 9.5 h by elevating the heating temperature from 80 ℃ to 120 ℃. The study also investigated the impact of the initial water content on heat transfer. It was observed that the saturated soil showed the slowest heating rate and the longest boiling stage. [Display omitted] • N-hexane and n-octane can be efficiently removed by low-temperature thermal treatment. • The relationship between kinetics constant and temperature was quantified by an exponential. • A mathematic model coupled incorporating heat and mass transfer was developed and validated. • Temporal and spatial changes of multiple physical fields were effectively simulated. [ABSTRACT FROM AUTHOR]

Aniline antioxidants (ANs) are widely used as industrial chemicals in products composed of rubber. ANs originate mainly from vehicles, where tire wear particles end up in dust and soil after being deposited on roads. Nowadays, limited information is available on the fate and seasonal variation of ANs in the road environment. In this study, we investigated the occurrence of 32 ANs in dust and soil from different road environments, including road dust, garage dust, parking lot dust, and green-belt soil. The total concentrations of ANs were 369 ng g−1 in road dust, 712 ng g−1 in garage dust, and 687 ng g−1 in parking lot dust. These concentrations are several times higher than that in green-belt soil (128 ng g−1). The highest concentrations of N-(1,3-dimethylbutyl)-N′-phenyl-1,4-phenylenediamine (6PPD) were found in dust and soil. Furthermore, notable seasonal differences were observed, with significantly higher concentrations of ANs in autumn than those in spring. In the main urban area, roads with high traffic volume exhibited higher concentrations of ANs than those with low traffic volume, indicating that ANs were produced by vehicle-related sources. [Display omitted] • ANs detected in road dust, parking lot dust, garage dust and green-belt soil. • 6PPD had the highest concentration among the ANs detected in dust and soil. • Dust samples showed higher concentrations of ANs than soil. • Concentrations of ANs are closely related to traffic volumes. [ABSTRACT FROM AUTHOR]

Abstract: Sulfide present in wastewaters and waste gases should be removed due to its toxicity, corrosivity, and malodorous property. Development of effective, stable, and feasible methods for sulfur recovery from sulfide attains a double objective of waste minimization and resource recovery. Here we report a novel fuel-cell-assisted iron redox (FC-IR) process for simultaneously recovering sulfur and electricity from synthetic sulfide wastewater. The FC-IR system consists of an oxidizing reactor where sulfide is oxidized to elemental sulfur by Fe(III), and a fuel cell where Fe(III) is regenerated from Fe(II) concomitantly with electricity producing. The oxidation of sulfide by Fe(III) is significantly dependent on solution pH. Increasing the pH from 0.88 to 1.96 accelerates the oxidation of sulfide, however, lowers the purity of the produced elemental sulfur. The performance of fuel cell is also a strong function of solution pH. Fe(II) is completely oxidized to Fe(III) when the fuel cell is operated at a pH above 6.0, whereas only partially oxidized below pH 6.0. At pH 6.0, the highest columbic efficiency of 75.7% is achieved and electricity production maintains for the longest time of 106h. Coupling operation of the FC-IR system obtains sulfide removal efficiency of 99.90%, sulfur recovery efficiency of 78.6±8.3%, and columbic efficiency of 58.6±1.6%, respectively. These results suggest that the FC-IR process is a promising tool to recover sulfur and energy from sulfide. [Copyright &y& Elsevier]

Abstract: A toxicity test was performed to investigate the possible harmful effects of tributyltin (TBT) on abalone (Haliotis diversicolor supertexta). Animals were exposed to TBT in a range of environmentally relevant concentrations (2, 10 and 50ng/L) for 30 days under laboratory conditions. TBT-free conditions were used as control treatments. The activity of antioxidant enzymes superoxide dismutase (SOD) and peroxidase (POD), and malondialdehyde (MDA), along with levels of haemolymph metabolites, and hepatopancreas histopathology were analyzed. The results showed that TBT decreased SOD activity, and increased POD level and MDA production in a dose-dependent way, indicating that oxidative injury was induced by TBT. Haemolymph metabolite measurements showed that TBT increased alanine and glutamate levels, and decreased glucose content, which suggested perturbation of energy metabolism. Elevated levels of acetate and pyruvate in the haemolymph indicated partial alteration of lipid metabolism. A decrease in lactate and an increase in succinate, an intermediate of the tricarboxylic acid (TCA) cycle, indicated disturbance of amino acid metabolism. Hepatopancreas tissues also exhibited inflammatory responses characterized by histopathological changes such as cell swelling, granular degeneration, and inflammation. Taken together, these results demonstrated that TBT was a potential toxin with a variety of deleterious effects on abalone. [Copyright &y& Elsevier]

Constructed wetlands for antibiotics and heavy metals removal have become important reservoirs of antibiotic resistance genes (ARGs) and heavy metal resistance genes (MRGs), especially in the substrates. Here, substrate-free hydroponic microcosms of Myriophyllum aquaticum were established; tetracyclines (TCs) and Cu(II) were added to evaluate the behaviours of ARGs and MRGs in the microcosms. Several ARGs, MRGs, and mobile genetic elements (MGE) were detected in the biofilms attached to the plants, ranging from 0.5 to 2.3 × 108 copies/g dry weight. ARGs and MRGs exhibited higher relative abundances in the effluent suspended solids (SS); however, their absolute amounts were much lower than those in conventionally constructed wetlands. Microcosms with TCs and Cu(II) exhibited a higher level of resistant genes than those with compound added singularly owing to co-selection pressure. The existence of TCs and copper significantly changed the microbial communities in the microcosms. The exogenous input of TC/Cu(II) and microbial community structure were the factors driving the occurrence of ARGs, whereas MRGs were more correlated with the copper addition. Thus, reducing the exogenous inputs of antibiotics /heavy metals and SS of the effluent is suggested for the mitigation of resistant genes in phytoremediation technologies working in the absence of conventional substrates. [Display omitted] • Tetracyclines and Cu(II) were efficiently removed by the substrate-free systems. • Resistant genes emerged despite the lack of any substrate material. • The absolute amounts of resistant genes were much lower in the hydroponic system. • Gene abundances related to biofilm formation were significantly higher than control. • Reducing solids in effluents may minimise the introduction of these genes. [ABSTRACT FROM AUTHOR]

The microbial colonization profiles on microplastics (MPs) in marine environments have recently sparked global interest. However, many studies have characterized plastisphere microbiomes without considering the ecological processes that underly microbiome assembly. Here, we carried out a three-timepoint exposure experiment at 1-, 4-, and 8-week and investigated the colonization dynamics for polyethylene, polypropylene, polystyrene, polyvinyl chloride, and acrylonitrile-butadiene-styrene MP pellets in natural coastal water. Using high-throughput sequencing of 16S rRNA, we found diversity and evenness were higher (p < 0.05) in the plastisphere communities than those in seawater, and microorganisms colonizing were co-influenced by environmental factors, polymer types, and exposure duration. Functional potential and co-occurrence network analysis revealed that MP exposure enriched the xenobiotic biodegradation potential and reduced the complexity of the MP microbial network. Simultaneously, null-model analyses indicated that stochastic processes contributed a bigger role than deterministic processes in shaping plastisphere microbial community structure with dispersal limitations contributing to a greater extent to microbial succession trajectories. These results implied the plastic surface had a more important role as a raft onto which microbes attach rather than selectively recruiting plastic-specific microbial colonizers. Our work strengthened the understanding of the ecological mechanisms by which microbial community patterns are controlled during colonization by plastic-associated microbes. [Display omitted] • Microorganisms colonizing microplastics (MPS) were co-influenced by multiply factors. • MPs exposure enriched the microbial xenobiotic biodegradation potential. • MPs exposure reduced the complexity of the plastisphere microbial community network. • Plastisphere microbial trajectory was mainly governed by stochastic process. • MPs had limit role to selectively recruiting plastic-specific microbial colonizers. [ABSTRACT FROM AUTHOR]

In order to investigate the explosion process of calcium carbide (CaC 2) dust in the acetylene (C 2 H 2) atmosphere, the explosion characteristics of C 2 H 2 gas and C 2 H 2 /CaC 2 dust gas-solid two-phase mixture were studied using a 20-L spherical vessel, and the chemical composition of solid residues after explosion were also analyzed. Experimental results showed that the P ex values of C 2 H 2 gas explosion rose first and then remained stable with the increasing stoichiometric ratio values (φ) of C 2 H 2 /air, while the (d P /d t) ex values tended to increase at early stage and then decrease, the inflection point of (d P /d t) ex values was φ = 1.78. The explosion severity and risk of C 2 H 2 gas were enhanced by adding CaC 2 dust, and the optimum additive concentration of CaC 2 dust was 100 g/m3. In the oxygen atmosphere, the C 2 H 2 /CaC 2 hybrid explosion was divided into two stages when the concentration of CaC 2 dust was over 300 g/m3. The explosion risk of the first stage (Stage Ⅰ) was much more serious, while the explosion severity of the second stage (Stage Ⅱ) was much more fierce. The solid residues of hybrid explosion only contained CaO in the oxygen atmosphere, however, Ca(OH) 2 and CaO were detected in the solid residues in the air atmosphere, owing to the combustion heat of C 2 H 2 gas in oxygen was higher than that in air. The hydrolysis reaction time of CaC 2 particle with large particle size was prolonged, and the diffusion of solid product layer and surface chemical reaction both influenced the hydrolysis process according to the shrinking core model. Based on the explosion and chemical analysis experiments, the explosion mechanism of C 2 H 2 /CaC 2 dust gas-solid two-phase mixture was analyzed systematically. [Display omitted] • Explosion severity and risk of hybrid C 2 H 2 /CaC 2 dust were systematically studied. • Participation process of CaC 2 dust in the secondary explosion was investigated. • Shrinking core model was used to describe the hydrolysis process of CaC 2 particle. • Positive feedback of C 2 H 2 combustion was proposed in the explosion mechanism. [ABSTRACT FROM AUTHOR]

Metalloids such as boron and silicon are key elements for plant growth and crop productivity. However, toxic metalloids such as arsenic are increasing in the environment due to inputs from natural sources and human activities. These hazardous metalloids can cause serious health risks to humans and animals if they enter the food chain. Plants have developed highly regulated mechanisms to alleviate the toxicity of metalloids during their 500 million years of evolution. A better understanding the molecular mechanisms underlying the transport and detoxification of toxic metalloids in plants will shed light on developing mitigation strategies. Key transporters and regulatory proteins responsive to toxic metalloids have been identified through evolutionary and molecular analyses. Moreover, knowledge of the regulatory proteins and their pathways can be used in the breeding of crops with lower accumulation of metalloids. These findings can also assist phytoremediation by the exploration of plants such as fern species that hyperaccumulate metalloids from soils and water, and can be used to engineer plants with elevated uptake and storage capacity of toxic metalloids. In summary, there are solutions to remediate contamination due to toxic metalloids by combining the research advances and industrial technologies with agricultural and environmental practices. ga1 • Evolutionary analysis identifies the origin and functional domains of candidate proteins for plant metalloid tolerance. • Genetic engineering of key genes from early-divergent plant lineages to food crops can improve tolerance to metalloids. • Discovery of novel compounds for plants and food crops can remove toxic metalloids from contaminated soil and water. • Integrated management of toxic metalloids in soil-plant system will benefit human health and food safety. [ABSTRACT FROM AUTHOR]

• Transcriptome profiling reveals key genes in Al-tolerant barley genotypes. • A novel tonoplast transporter HvABCB25 is identified for barley Al tolerance. • ABCB25 is evolved from the Order of Zygnematales in streptophyte algae. • HvABCB25 is expressed predominately in root tips for vacuolar sequestration of Al. Aluminum (Al) stress in acid soils is one of the major factors limiting crop productivity. ATP binding cassette (ABC) transporters have numerous roles in plants, but the link between ABCB protein subfamily and plant Al tolerance is still elusive. Here, we identified and characterized a novel tonoplast HvABCB25 in barley root cells. HvABCB25 was up-regulated in the transcriptome of Al-tolerant wild barley XZ16 under Al treatment and was highly Al-inducible in root tips. ABCB25 is originated from Streptophyte algae and evolutionarily conserved in land plants. Moreover, silencing HvABCB25 in Al-tolerant XZ16 led to significant suppression of Al tolerance as indicated by significantly reduced root growth and enhanced Al accumulation in root cells. Conversely, HvABCB25 -overexpressed plants and Golden Promise showed similar Al content in whole roots and in cell sap, but the overexpression lines exhibited significantly higher Al-induced relative root growth and dry weight. Al florescence in cytosol of root cells were significantly less in overexpression lines than that in GP. These results indicated that overexpressing HvABCB25 may be responsible for Al detoxification via vacuolar Al sequestration in barley roots, providing useful insight into the genetic basis for a new Al detoxification mechanism towards plant Al tolerance in acid soils. [ABSTRACT FROM AUTHOR]

• MSWI fly ash treated by plasma was chemically inert and mechanically improved. • Impacts on eco-toxicity and human toxicity for plasma vitrification were lowest. • Highest climate change impacts was observed in rotary kiln co-treatment scenario. • Efficient pollution abatement system should be combined with vitrification. • Implications and opportunities to sustainable materials management were discussed. Fly ash from municipal solid waste incineration is considered as a hazardous waste, which would raise great threats on environmental safety due to the inherent toxic heavy metals and organic pollutants. In this study, we applied the life cycle assessment to evaluate the thermal plasma vitrification process for stabilization of fly ash from municipal solid waste incineration. We established four scenarios: (i) plasma vitrification, including centralized and off-site plasma treatment, (ii) fuel-based vitrification, (iii) water-washing treatment followed by a rotary kiln, and (iv) conventional solidification and landfill. We found that the environmental impacts, especially toxicity to ecosystem quality and human health, could be significantly reduced by deploying plasma vitrification technology. We also found that centralized plasma vitrification facilities possessing larger treatment capabilities with clean electricity could further reduce the environmental impacts. In contrast, the water-washing treatment exhibited the highest environmental impacts due to the emissions of vaporized heavy metals. Based on the LCA and sensitivity analysis, we confirmed that the thermal plasma vitrification should be considered as an environmentally-friendly solution to sustainable treatment of fly ash from municipal solid waste incineration. Lastly, we provided several perspectives and prospects of plasma vitrification for realizing the sustainable materials management. [ABSTRACT FROM AUTHOR]

• The potential risks of paclobutrazol on pickling food was investigated. • Enantioselective degradation and conversion of paclobutrazol was observed. • Enantiomeric bioactivities were found in the influence of microbial composition. • Paclobutrazol showed enantiomeric bioactivity in inhibiting microbial metabolism. For decades, pesticides have been widely used for controlling pests and protecting crops around the world, and the food safety issues caused by these compounds have raised widespread concern. However, the different enantioselective behaviors and biological activities of chiral pesticide enantiomers are often ignored. In this work, a novel method was put forward to investigate the enantioselective effects and potential risks of two paclobutrazol enantiomers during cucumber pickling process. The degradation kinetics indicated that when paclobutrazol reside in cucumber and was introduced into the pickling process, the half-time of paclobutrazol isomers were significantly different (9.24 d and 16.6 d), and the conversion phenomenon between the two enantiomers could also be observed. In addition, results from 16S rRNA and ITS sequencing shown that (2R, 3R)-paclobutrazol and (2S, 3S)-paclobutrazol have an obviously enantiomeric effects on microbial community of pickling system and the degradation of paclobutrazol was probably attributed to the presence of Pseudomonas and Serratia. Finally, the microorganisms functions were found to be disrupted under the exposure of (2R, 3R)-paclobutrazol and metabolic function of microorganisms to xenobiotic was inhibited, which might cause potential risks to the quality of preserved foods. In summary, we have devised a method and provided a novel insight into the potential risks of chiral pesticide residues on food safety and human health. [ABSTRACT FROM AUTHOR]

• Chlorate-reducing Ochrobactrum anthropi XM-1 was isolated and first reported. • XM-1 can tolerate a wide range of pH, and withstand more acidic conditions. • XM-1 reduced chlorate up to 200 mM promising for high-strength chlorate reduction. • Clr and Cld activities were detected in XM-1 grown aerobically and anaerobically. A Gram-negative chlorate-reducing bacterial strain XM-1 was isolated. The 16S rRNA gene sequence identified the isolate as Ochrobactrum anthropi XM-1, which was the first strain of genus Ochrobactrum reported having the ability to reduce chlorate. The optimum growth temperature and pH for strain XM-1 to reduce chlorate was found to be 30 °C and 5.0–7.5, respectively, under anaerobic condition. Strain XM-1 could tolerate high chlorate concentration (200 mM), and utilize a variety of carbohydrates (glucose, L-arabinose, D-fructose, sucrose), glycerin and sodium citrate as electron donors. In addition, oxygen and nitrate could be used as electron acceptors, but perchlorate could not be reduced. Enzyme activities related to chlorate reducing were characterized in cell extracts. Activities of chlorate reductase and chlorite dismutase could be detected in XM-1 cells grown under both aerobic and anaerobic conditions, implying the two enzymes were constitutively expressed. This work suggests a high potential of applying Ochrobactrum anthropi XM-1 for remediation of chlorate contamination. [ABSTRACT FROM AUTHOR]