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Microplastics are plastic particles with particle size less than 5 mm in the environment. As an emerging organic pollutant, the presence of microplastics in the soil environment has been widely noticed. Also, due to the overuse of antibiotics, a large amount of antibiotics that cannot be fully absorbed by humans and livestock enter the soil environment in the form of urine or manure, making the soils suffer from serious antibiotic contamination problems. To address the environmental problems of microplastics and antibiotic contamination in soils, this study was conducted to investigate the effects of PE microplastics on antibiotic degradation, microbial community characteristics and ARGs in tetracycline-contaminated soils. The results showed that the addition of PE microplastics inhibited the degradation of tetracycline, and significantly increased the organic carbon content and decreased the neutral phosphatase activity. The addition of PE microplastics significantly reduced the alpha diversity of soil microbial community. Compared to the single tetracycline contamination. In addition, combined contamination with PE microplastics and tetracycline significantly affected bacterial genera such as Aeromicrobium , Rhodococcus , Mycobacterium and Intrasporangium. Metagenome sequencing studies revealed that the addition of PE microplastics inhibited the dissipation of ARGs in tetracycline-contaminated soils. There were strong positive correlations between Multidrug, Aminoglycoside and Clycopeptide resistance genes and Chloroflexi and Proteobacteria in tetracycline contaminated soils, and there was a strong positive correlation between Aminoglycoside resistance genes and Actinobacteria in combined contamination of PE microplastics and tetracycline. This study will provide some data support for the current environmental risk assessment of the coexistence of multiple contaminants in soil. [Display omitted] • The addition of PE MPs inhibits the degradation of TC. • PE MPs significantly increased the content of SOC in TC contaminated soil. • Co-existence of PE MPs and TC significantly affected neutral phosphatase activity. • Co-existence of PE MPs and TC significantly decreased soil microbial diversity. • PE MPs inhibited the dissipation of ARGs in TC-contaminated soils. [ABSTRACT FROM AUTHOR]

Microplastics are plastic particles less than 5 mm in diameter and are widely present in water environments. Their unique surface structures can adsorb coexisting pollutants in the surrounding environment, such as antibiotics and metal ions, leading to compound pollution. The adsorption of ciprofloxacin on polyethylene microplastics under different environmental conditions (pH and salinity) was investigated. The Freundlich model fitted well at 25 °C, indicating that the adsorption of ciprofloxacin by polyethylene microplastics was multilayered, and Fourier Transform infrared spectroscopy (FTIR) analysis indicated that the adsorption of ciprofloxacin by polyethylene microplastics was physical. The kinetic adsorption of ciprofloxacin on polyethylene microplastics followed a pseudo-second-order mode. Heavy metals (Cu2+, Cr3+, Cr6+, Cd2+, and Pb2+) affected the adsorption of ciprofloxacin by microplastics, which was related to the type and concentration of metal ions and the valence state of the ions. The acute toxicity of microplastics and the microplastic-ciprofloxacin-Cu2+ complex were evaluated using luminescent Photobacterium phosphoreum , demonstrating the polyethylene toxicity microplastic-ciprofloxacin-Cu2+ complex was mainly caused by Cu2+ and ciprofloxacin rather than microplastics. This study provides theoretical support for the environmental behavior and ecological effects of microplastics in aqueous environments. [Display omitted] • Ciprofloxacin adsorption on polyethylene microplastics is multilayered. • Adsorption kinetic shows a pseudo-second order pattern. • The concentration and valence of heavy metals influence the adsorption process. • Toxicity of complex pollutants are mainly caused by metal ions and ciprofloxacin. [ABSTRACT FROM AUTHOR]

Combining pre-oxidation with activated carbon adsorption was explored as an ideal approach for removing iodine from water source to eliminate the formation of Iodinated trihalomethanes (I-THMs). Compared with permanganate and monochloramine, chlorine is more suitable as pre-oxidant to obtain higher active iodine species (HOI/I 2). Active iodine species adsorption using both powdered activated carbon (PAC) and granular activated carbon (GAC) can be well fitted the pseudo-second-order kinetic model indicating that chemical adsorption was the dominant mechanism for HOI/I 2 adsorption. The average pore size of activated carbons was the most strongly correlated with the adsorption capacity (R2 > 0.98), followed by methylene blue (R2 > 0.76), pore volume (R2 > 0.70) and iodine number (R2 > 0.67). Moreover, three models, including intraparticle diffusion, Byod kinetic, and diffusion-chemisorption were used to illustrate the mechanisms of HOI/I 2 adsorption. Chemical adsorption was the dominant mechanism for HOI/I 2 adsorption. In summary, at the molar ratio of [NaClO] and [I−] as 1.2, pre-chloriantion time of 5 min, subsequently dosage of 15 mg/L of PAC E with 20 min adsorption can remove 79.8% iodine. In addition, the combined process can eliminate 61%–87.2% of I-THMs in the subsequent chlor(am)ination. The results indicate that pre-chlorination combined with PAC can effectively removed HOI/I 2 and attenuate I-THMs formation in the subsequent disinfection process. [Display omitted] • Optimizing prechlorination can enhance HOI/I 2 formation, facilitating subsequent adsorption. • Active iodine species (HOI/I 2) were chemically adsorpted by PACs and GACs. • HOI/I 2 adsorption followed pseudo-second-order kinetics. • Film diffusion was the rate-limiting process for HOI/I 2 adsorption on activated carbon. • Pre-chlorination with PAC adsorption can effectively remove HOI/I 2 and attenuate I-THM formation. [ABSTRACT FROM AUTHOR]

Organic chloramines (OCs) have become one of the research focuses in the field of drinking water treatment due to its limited oxidation and sterilization ability as well as potential cytotoxicity and genetic toxicity to the public. Among widespread OCs, produced by chlorinating cytosine are a typical one exists during chlorine disinfection. OCs degradation during UV, chlorination and UV/chlorine processes were systematically investigated. UV irradiation at 254 nm could effectively degrade OCs by 96.6% after 60 min, mainly because N–Cl bond had significant UV absorption at 250–280 nm leading to the generation of Cl• and HO•. Direct chlorination had poor removal of OCs with the OCs concentration increased first and then decreased as time went by. On the other hand, the removal of OCs during UV/chlorination was much higher than that during chlorination, but was worse than that during UV alone. pH had a minor effect on OCs decomposition via UV irradiation, whereas the effect was pronounced in the chlorination and UV chlorine processes. UV wavelength can affect the degradation of OCs with efficiency decreased in the order of UV 254 > UV 265 > UV 275. The total yields of disinfection by-products (DBPs) during the degradation of OCs followed UV/chlorine > UV > chlorination. CH and DCAA were the two dominant types of DBPs among detected 7 DBPs. DBPs yield followed the order of UV254 > UV265 > UV275 at pH 6.0 and 7.0. After UV 265 irradiation, DBPs yield slightly decreased by 2.4%, 3.0% and 6.6% with the pH increased from 6.0 to 9.0. The results can provide theoretical basis for effective control of OCs in drinking water. [Display omitted] • Stable organic chloramines were produced during cytosine chlorination. • UV irradiation can effectively degrade the generated organic chloramine. • The concentrations of DOC and TN in the solution were negligibly changed during chlorination. • OCs photodecay efficiency decreased in the order of 254 nm > 265 nm > 275 nm. • DBPs yield from OCs followed the order of UV/chlorine > UV > chlorination. [ABSTRACT FROM AUTHOR]

The low cost and non-toxic of magnesium oxides make it a potential eco-friendly material for arsenic removal. Polysaccharide is a kind of green modifier to obtain nanoscale MgO particles with a higher adsorption affinity. In this study, the impact of chain structures of polysaccharides on the morphology features and arsenate removal efficiency of MgO-NPs were investigated. Pullulan and starch facilitated the synthesis of flower-like MgO-NPs, and pectin facilitated the synthesis of plate-like ones. Although the two kinds of flower-like MgO-NPs undergone similar time to reach equilibrium, the one obtained from the starch-synthesis route showed a higher arsenate adsorption capacity (98 mg g−1), due to that their bushy and smaller petals on the surface provide more active sites for arsenic adsorption. The pectin-synthesis route also produced MgO-NPs with higher arsenate adsorption capacity (101 mg g−1), ascribed to stacking of nano-plates on their surfaces facilitated to form defect surfaces. However, due to their lower BET area, the plate-like MgO-NPs took twice times to reach equilibrium for arsenic adsorption compared with the others. In the stage for the hydrolysis of MgO, hydroxyl groups on the polymer chain provide active sites to physically trap or bond with MgO particles and then to produce hydrolyzed precursors. The poly chain containing inter- and intra-hydroxyl groups directed MgO molecular growing into hydroxide crystals with 3D frameworks during their nucleation and growth. However, pectin only provides inter-hydroxyl groups and directs to form hydroxides with 2D frameworks. Furthermore, the rapid-nucleation vs. slow-growth model in the stage of pyrolysis of hydroxide crystals successfully interprets the thinner petals and complex chemical phases of the final nanoparticles obtained from the pullulan-synthesis route. This work may provide direction and perspectives for the rational design of well-performing MgO materials for arsenate removal. [Display omitted] • Ploymorphous MgO-NPs for efficient arsenate removal were synthesized. • Pullulan and starch facilitated to synthesize MgO nano-flowers. • Pectin helped to synthesize MgO nano-plates. • Polysaccharide's structure controls the formation of 2D or 3D nanoparticles. • Small flower-like and plate-like structures are benefit to arsenate removal. [ABSTRACT FROM AUTHOR]

The fastest-growing microbe Vibrio natriegens is an excellent platform for bioproduction processes. Until now, this marine bacterium has not been examined for bioremediation applications, where the production of substantial amounts of biomass would be beneficial. V. natriegens can perform extracellular electron transfer (EET) to Fe(III) via a single porin-cytochrome circuit conserved in Vibrionaceae. Electroactive microbes capable of EET to Fe(III) usually also reduce toxic metals such as carcinogenic Cr(VI), which is converted to Cr(III), thus decreasing its toxicity and mobility. Here, the performance of V. natriegens was explored for the bioremediation of Cr(VI). At a density of 100 mg/mL, V. natriegens removed 5–20 mg/L Cr(VI) within 30 s and 100 mg/L Cr(VI) within 10 min. In comparison, the model bacterium Escherichia coli grown to a comparable cell density removed Cr(VI) 36 times slower. To eliminate Cr(VI), V. natriegens had to be metabolically active, and functional outer-membrane c -type cytochromes were required. At the end of the Cr(VI) removal process, V. natriegens had reduced all of it into Cr(III) while adsorbing more than half of the metallic ions. These results demonstrate that V. natriegens , with its fast metabolism, is a viable option for the rapid treatment of aqueous pollution with Cr. [Display omitted] • The fast-growing microbe Vibrio natriegens can reduce and adsorb toxic chromium. • High-density V. natriegens removed 5–20 mg/L Cr(VI) within 30 s. • V. natriegens at the same density also removed 100 mg/L Cr(VI) within minutes. • Cr(VI) was reduced extracellularly and Cr(III) was adsorbed by the microbes. • A porin-cytochrome complex is likely involved in Cr(VI) conversion. [ABSTRACT FROM AUTHOR]

Coronary atherosclerotic disease (CAD) is often accompanied by peripheral atherosclerosis, resulting in a higher risk of ischemia and cardiovascular death. Exposure to metals is associated with atherosclerotic plaques at specific sites. However, less is known about the effects of mixed metals on systemic atherosclerotic burden in CAD patients. To investigate the association of metal mixtures with systemic atherosclerotic burden in a CAD population. A cross-sectional study including 1562 CAD patients from Southwest China was conducted. The levels of 10 blood metals were measured via inductively coupled plasma spectrometry. More than one vessel with a stenosis ≥50% vessel diameter was defined as CAD. Carotid and lower limb atherosclerosis was assessed by using ultrasound, and coronary atherosclerosis was quantified via arterial angiography. Systemic atherosclerosis was scored according to the presence or absence of lesions at the three sites and the total number of lesions. To investigate the combined impacts and interaction effects of metals, Bayesian kernel machine regression was used. Weighted quantile regression was used to identify the contributions of the metals. Significant overall associations of mixed metals with systemic atherosclerotic burden were found. These positive overall associations were mainly driven by Cd, Cu and Pb in systemic atherosclerosis. The main contributing factors were As and Cu for coronary atherosclerosis as well as Cd, Cu and Pb for carotid and lower limb atherosclerosis. Cd and Pb or Cr can interact, and Pb interacts with age, sex and alcohol. In CAD patients, exposure to combinations of metals was highly positively associated with systemic atherosclerotic burden. These significant trends were more pronounced in the peripheral arteries and carotid arteries. Controlling environmental metal exposure can contribute to reducing systemic atherosclerosis in CAD patients. [Display omitted] • Mixed metal exposure is associated with systemic atherosclerosis（AS）in CAD patients. • Association of mixed metals with systemic AS is drived by peripheral arteries. • Cd, Cu and Pb are the driven metals of peripheral AS, As and Cu for coronary AS. • Metal-metal interactions are apparent between Cd and Pb or Cr. • Metal-traditional factor interactions between Pb and age, sex or alcohol are obvious. [ABSTRACT FROM AUTHOR]

Effective strategies to improve charge separation in semiconductor particles are critical for improving the photodegradation of organic pollutants at levels sufficient for environmental applications. Herein, Bi 2 MoO 6 (BMO MOF), comprising both nanoparticles (NPs) and quantum dots (QDs), was synthesized from a bismuth-based metal-organic framework (Bi-MOF) precursor. Surface defects on BMO MOF , the combination of NPs and QDs, and modified energy band edges improved photogenerated charge separation and facilitated redox reactions. When compared to BMO derived from uncoordinated Bi, the BMO MOF photocatalyst (PC) was more efficient at photodegrading tetracycline hydrochloride (TCH) and ciprofloxacin (CIP), two widely-used antibiotics ubiquitous in wastewater, as well as the carcinogenic pollutant rhodamine B (RhB). BMO MOF was then loaded on the biopolymer bacterial cellulose (BC) to further enhance photocatalytic performance and facilitate the recovery of the PC after water treatment processes. The novel BMO MOF /BC photocatalytic flakes were significantly larger than pure BMO MOF , and thus easier to recuperate. Furthermore, anchoring BMO MOF on BC flakes augmented significantly the photodegradation of TCH, CIP, and RhB, mainly because hydroxyl groups in BC act as hole traps facilitating photogenerated electron-hole separation. Results obtained with BMO MOF /BC highlight promising approaches to develop optimal PCs for aqueous pollutants degradation. [Display omitted] • Bi 2 MoO 6 (BMO) was synthesized from a bismuth metal-organic framework precursor. • BMO MOF comprised nanoparticles with defects and quantum dots. • BMO MOF was anchored on large bacterial cellulose flakes easy to recover from water. • Versatile BMO MOF /BC photodegrades efficiently both persistent antibiotics and dyes. • BMO MOF /BC was stable under visible light with most pollutants. [ABSTRACT FROM AUTHOR]

Volatile fatty acids (VFAs) are the building blocks of the chemical industry, and they are the primary contributors to the planet's organic carbon cycle. VFA production from fossil fuels (mostly petroleum) is unsustainable, pollutes the environment, and generates greenhouse gases. As a result of these issues, there is a pressing need to develop alternate sources for the long-term generation of VFAs via anaerobic digestion. The accessible feedstocks for its sustainable production, as well as the influencing parameters, are discussed in this review. The use of VFAs as a raw material to make a variety of consumer products is reviewed in order to find a solution. It also bridges the gap between traditional and advanced VFA production and utilization methods from a variety of solid and liquid waste sources for economical stability. [Display omitted] • VFA production from different solid and liquid wastes are reviewed. • Influential parameters for VFAs production are evaluated. • Economical approaches are discussed for VFA production on scaleup. • VFAs applications to produce various consumers' products are presented. [ABSTRACT FROM AUTHOR]

Volatile fatty acids (VFAs) are the building blocks of the chemical industry, and they are the primary contributors to the planet's organic carbon cycle. VFA production from fossil fuels (mostly petroleum) is unsustainable, pollutes the environment, and generates greenhouse gases. As a result of these issues, there is a pressing need to develop alternate sources for the long-term generation of VFAs via anaerobic digestion. The accessible feedstocks for its sustainable production, as well as the influencing parameters, are discussed in this review. The use of VFAs as a raw material to make a variety of consumer products is reviewed in order to find a solution. It also bridges the gap between traditional and advanced VFA production and utilization methods from a variety of solid and liquid waste sources for economical stability. [Display omitted] • VFA production from different solid and liquid wastes are reviewed. • Influential parameters for VFAs production are evaluated. • Economical approaches are discussed for VFA production on scaleup. • VFAs applications to produce various consumers' products are presented. [ABSTRACT FROM AUTHOR]

Nanoscale zero-valent iron (nZVI) has been extensively used to remove various pollutants. However, the rapid deactivation due to aggregation and surface passivation severely limits its practical application. In this study, a novel composite with nZVI supported by pinecone biochar (nZVI-PBC) was successfully synthesized and used for the removal of high concentration Cr(VI) from aqueous solution in the presence of Shewanella oneidensis MR-1 (MR-1). The results showed that the nZVI-PBC coupling with MR-1 (nZVI-PBC/MR-1) exhibited an excellent removal performance for high concentration Cr(VI) compared to the nZVI-PBC alone. Under optimal conditions, 100 mg/L Cr(VI) could be removed completely by nZVI-PBC/MR-1 within 48 h, while only 39.50% of Cr(VI) was removed by nZVI-PBC alone. The improvement of Cr(VI) removal is due to the dissolution of the surface passivation layer of nZVI-PBC, formation of sorbed Fe(II) in the presence of MR-1, and an important role of extracellular polymeric substance (EPS) derived from MR-1. X-ray photoelectron spectroscopy (XPS) and Cr K-edge X-ray absorption near-edge structure spectra (XANES) confirmed that most Cr(VI) was reduced to insoluble Cr(III) and formed Cr 2 O 3 , Cr x Fe 1-x (OH) 3 and FeCr 2 O 4 precipitates, and a small amount of unreduced Cr(VI) was immobilized through adsorption and complexation. The results suggest that nZVI-PBC/MR-1 can effectively overcome the limitations of nZVI and achieve highly efficient removal of high concentration Cr(VI). [Display omitted] • nZVI-PBC coupling with MR-1 exhibited an excellent capacity for Cr(VI) removal. • Sorbed Fe(II) could act as a strong reductant to reduce Cr(VI) to Cr(III). • The EPS derived from MR-1 play an important role in Cr(VI) removal. • nZVI-PBC coupling with MR-1 overcomes the aggregation and passivation of nZVI. • The mechanism of Cr(VI) removal by nZVI-PBC coupling with MR-1 was proposed. [ABSTRACT FROM AUTHOR]

Pyrimidine and purine bases (adenine, cytosine, guanine and thymine) are important precursors of organic chloramines (OC) and disinfection by-products (DBPs) during chlor(am)ination. In this study, OC and DBP formation derived from pyrimidine and purine bases during chlor(am)ination, post-chlor(am)ination after pretreated by UV alone and UV/chlorination were systematically investigated with ultraviolet light-emitting diodes (UV-LEDs, 265 and 275 nm) and low pressure mercury lamp (LPUV, 254 nm). The results revealed that higher OC formation was observed during chlorination than that during chloramination of pyrimidine and purine bases. The degradation of pyrimidine and purine bases followed the pseudo-first-order kinetics. Both solution pH and UV wavelength played vital influence on the degradation of pyrimidine and purine bases. In terms of fluence-based rate constants (k obs), the degradation rates of pyrimidine and purine bases decreased in the order of 275 nm > 265 nm > 254 nm in alkaline conditions. The synergistic effects of k obs, chlorine, k obs, •OH and k obs, RCS contributed to the differences of pyrimidine and purine bases degradation at different pH values and UV wavelengths. A vital suppression of OC formation was observed during post-chlorination after pretreated by 275 nm UV-LED/chlorination. In addition, compared with LPUV (254 nm), less DBP formation was observed at UV-LED (275 nm), especially during the UV/chlorine process. The phenomena obtained in this study indicated that 275 nm UV-LED combined with chlorine could be a preferred method to promote pyrimidine and purine bases degradation and control OC and DBP formation in practical water treatment. [Display omitted] • Higher levels of OC were observed during chlorination of pyrimidine and purine bases. • k obs of pyrimidine and purine bases during UV/chlorine process decreased in the order of 275 > 265 > 254 nm at pH > 7.0. • k obs, chlorine, k obs, •OH and k obs, RCS presented synergistic effects of on the removal of pyrimidine and purine bases. • UV/chlorine pretreatment significantly suppressed OC formation, but also enhanced the DBP formation. [ABSTRACT FROM AUTHOR]