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A novel selective denitrification process, referred as O 3 -ethanol oxidation method, was developed by injecting O 3 and ethanol mixtures into the simulated flue gas duct. The organic radicals, generated through the ethanol oxidation by O 3 , can oxidize NO into NO 2 , and finally into important industrial raw, namely, nitrate organics or aqueous nitrate acids. The residual ethanol in the tail can be recycled. The CO 3 2− , HCO 3 − and SO 2 in the flue gas hardly exhibit any effect on the NO X removal. Compared to the conventional O 3 oxidation method, the present method shows higher selective oxidation of NO, higher NO X removal and less O 3 consumption as well as proves lower initial investment and operating costs with more compact equipment. [ABSTRACT FROM AUTHOR]

A novel, simple, reproducible and low-cost strategy is introduced for the size- and shape-controlled synthesis of iron–aluminum mixed oxide nanoparticles (NIAO( x / y )). The as-synthesized NIAO( x / y ) catalyze decomposition of H 2 O 2 yielding highly reactive hydroxyl radicals ( OH) for NO X and SO 2 removal. 100% SO 2 removal is achieved. NIAO( x / y ) with Fe/Al molar ratio of 7/3 (NIAO(7/3)) shows the highest NO X removal of nearly 80% at >170 °C, whereas much lower NO X removal (<63%) is obtained for NIAO(3/7). The melting of aluminum oxides in NIAO(7/3) promotes the formation of lamellar products, thus improving the specific surface areas and mesoporous distribution, benefiting the production of OH radicals. Furthermore, the NIAO(7/3) leads to the minor increase of points of zero charges (PZC), apparent enhancement of FeOH content and high oxidizing ability of Fe(III), further improving the production of OH radicals. However, the NIAO(3/7) results in the formation of aluminum surface-enriched spherical particles, thus decreasing the surface atomic ratio of iron oxides, decreasing OH radical production. More importantly, the generation of FeOAl causes the decline of active sites. Finally, the catalytic decomposition of H 2 O 2 on NIAO( x / y ) is proposed. And the well catalytic stability of NIAO(7/3) is obtained for evaluation of 30 h. [ABSTRACT FROM AUTHOR]

Abstract: To assess the “bioaccessible” pool of mycelia-bound polycyclic aromatic hydrocarbons (PAHs) and to quantify its biodegradation kinetics in soil, a soil-slurry system containing mycelial pellets of Phanerochaete chrysosporium as a separable biophase was set up. In sterilized and unsterilized soil-slurry, the distribution and dissipation of phenanthrene and pyrene in soil, fungal body of P. chrysosporium and water were independently quantified over the incubation periods. Biosorption and biodegradation contributions to bio-dissipation of dissolved- and sorbed-PAHs were identified. The biodegradation kinetics of PAHs by allochthonous P. chrysosporium and soil wild microorganisms was higher than those predicted by a coupled desorption–biodegradation model, suggesting both allochthonous and wild microorganisms could access sorbed-PAHs. The obvious hysteresis of PAHs in soil reduced their biodegradation, while the biosorbed-PAHs in P. chrysosporium body as an interim pool exhibited reversibly desorption and were almost exhausted via biodegradation. Both biosorption and direct biodegradation of PAHs in soil slurry were stimulated by allochthonous P. chrysosporium. After 90-day incubation, the respective biodegradation percentages for phenanthrene and pyrene were 63.8% and 51.9% in the unsterilized soil without allochthonous microorganisms, and then increased to 94.9% and 90.6% when amended with live P. chrysosporium. These indicate that allochthonous and wild microorganisms may synergistically attack sorbed-PAHs. [Copyright &y& Elsevier]

Polyethylene terephthalate (PET or polyester) is a commonly used plastic and also contributes to the majority of plastic wastes. Mealworms (Tenebrio molitor larvae) are capable of biodegrading major plastic polymers but their degrading ability for PET has not been characterized based on polymer chain size molecular size, gut microbiome, metabolome and transcriptome. We verified biodegradation of commercial PET by T. molitor larvae in a previous report. Here, we reported that biodegradation of commercial PET (M w 29.43 kDa) was further confirmed by using the δ13C signature as an indication of bioreaction, which was increased from − 27.50‰ to − 26.05‰. Under antibiotic suppression of gut microbes, the PET was still depolymerized, indicating that the host digestive enzymes could degrade PET independently. Biodegradation of high purity PET with low, medium, and high molecular weights (MW), i.e. , M w values of 1.10, 27.10, and 63.50 kDa with crystallinity 53.66%, 33.43%, and 4.25%, respectively, showed a mass reduction of > 95%, 86%, and 74% via broad depolymerization. Microbiome analyses indicated that PET diets shifted gut microbiota to three distinct structures, depending on the low, medium, and high MW. Metagenome sequencing, transcriptomic, and metabolic analyses indicated symbiotic biodegradation of PET by the host and gut microbiota. After PET was fed, the host's genes encoding degradation enzymes were upregulated, including genes encoding oxidizing, hydrolyzing, and non-specific CYP450 enzymes. Gut bacterial genes for biodegrading intermediates and nitrogen fixation also upregulated. The multiple-functional metabolic pathways for PET biodegradation ensured rapid biodegradation resulting in a half-life of PET less than 4 h with less negative impact by PET MW and crystallinity. [Display omitted] • High-crystallinity PET biodegradation was confirmed by testing change of δ13C. • Depolymerization is independent of gut microbes. • Polymer molecular size influences degradation rates. • Gut microbiomes synergistically biodegrade intermediates and provide nitrogen sources. • Upregulation of host genes for PET depolymerization and metabolism. [ABSTRACT FROM AUTHOR]

Microplastics (MPs) are a significant component of global pollution and cause widespread concern, particularly in wastewater treatment plants. While understanding the impact of MPs on nutrient removal and potential metabolism in biofilm systems is limited. This work investigated the impact of polystyrene (PS) and polyethylene terephthalate (PET) on the performance of biofilm systems. The results revealed that at concentrations of 100 and 1000 μg/L, both PS and PET had almost no effect on the removal of ammonia nitrogen, phosphorus, and chemical oxygen demand, but reduced the removal of total nitrogen by 7.40–16.6%. PS and PET caused cell and membrane damage, as evidenced by increases in reactive oxygen species and lactate dehydrogenase to 136–355% and 144–207% of the control group. Besides, metagenomic analysis demonstrated both PS and PET changed the microbial structure and caused functional differences. Some important genes in nitrite oxidation (e.g. nxrA), denitrification (e.g. narB , nirABD , norB , and nosZ), and electron production process (e.g. mqo , sdh , and mdh) were restrained, meanwhile, species contribution to nitrogen-conversion genes was altered, therefore disturbing nitrogen-conversion metabolism. This work contributes to evaluating the potential risks of biofilm systems exposed to PS and PET, maintaining high nitrogen removal and system stability. [Display omitted] • PS and PET inhibited TN removal by 7.40–16.6% in biofilm system. • PS and PET enhanced ROS and LDH production and lead to cell and membrane damage. • PS and PET changed the microbial structure and created functional differences. • Some functional genes associated with nitrogen removal were suppressed. • Genes related to electron donor and ATP production in TCA cycle were restrained. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) is a mass-produced fossil-based plastic polymer that contributes to catastrophic levels of plastic pollution. Here we demonstrated that Tenebrio molitor (mealworms) was capable of rapidly biodegrading two commercial PET resins (microplastics) with respective weight-average molecular weight (M w) of 39.33 and 29.43 kDa and crystallinity of 22.8 ± 3.06% and 18 ± 2.25%, resulting in an average mass reduction of 71.03% and 73.28% after passage of their digestive tract, and respective decrease by 9.22% and 11.36% in M w of residual PET polymer in egested frass. Sequencing of 16 S rRNA gene amplicons of gut microbial communities showed that dominant bacterial genera were enriched and associated with PET degradation. Also, PICRUSt prediction exhibited that oxidases (monooxygenases and dioxygenases), hydrolases (cutinase, carboxylesterase and chitinase), and PET metabolic enzymes, and chemotaxis related functions were up-regulated in the PET-fed larvae. Additionally, metabolite analyses revealed that PET uptake caused alterations of stress response and plastic degradation related pathways, and lipid metabolism pathways in the T. molitor larvae could be reprogrammed when the larvae fed on PET. This study provides new insights into gut microbial community adaptation to PET diet under nutritional stress (especially nitrogen deficiency) and its contribution to PET degradation. [Display omitted] • Confirmation of commercial PET biodegradation by Tenebrio molitor. • Minor difference in degradation performance of two PET polymers. • Spiroplasma , Dysgonomonas and Hafnia-Obesumbacterium associated with PET degradation. • Both host and gut microbiota contributed enzyme repertoire to PET degradation. • A plausible mechanism was proposed based on 16 S rRNA and metabolome analyses. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIP) has received considerable attention in recent decades due to its high ecological risk. However, little is known about the potential response of macrophytes and microbes to varying levels of CIP exposure in constructed wetlands. Therefore, lab-scale manganese ore-based tidal flow constructed wetlands (MO-TFCWs) were operated to evaluate the responses of macrophytes and microbes to CIP over the long term. The results indicated that total nitrogen removal improved from 79.93% to 87.06% as CIP rose from 0 to 4 mg L−1. The chlorophyll content and antioxidant enzyme activities in macrophytes were enhanced under CIP exposure, but plant growth was not inhibited. Importantly, CIP exposure caused a marked evolution of the substrate microbial community, with increased microbial diversity, expanded niche breadth and enhanced cooperation among the top 50 genera, compared to the control (no CIP). Co-occurrence network also indicated that microorganisms may be more inclined to co-operate than compete. The abundance of the keystone bacterium (involved in nitrogen transformation) norank_f__A0839 increased from 0.746% to 3.405%. The null model revealed drift processes (83.33%) dominated the community assembly with no CIP and 4 mg L−1 CIP. Functional predictions indicated that microbial carbon metabolism, electron transfer and ATP metabolism activities were enhanced under prolonged CIP exposure, which may contribute to nitrogen removal. This study provides valuable insights that will help achieve stable nitrogen removal from wastewater containing antibiotic in MO-TFCWs. [Display omitted] • Microbial diversity and niche breadth increased under ciprofloxacin (CIP) exposure. • The cooperation among dominant microbes and keystone species was promoted by CIP. • Enhanced electron transport activity of microbes exposed to MO-TFCW by CIP. • Diversity and cooperation of microbes as drivers of improved nitrogen removal. • Macrophytes and microbes showed adaptive response to CIP exposure. [ABSTRACT FROM AUTHOR]

Manganese dioxide decorated graphene oxide (GOM) was prepared via fixation of crystallographic MnO 2 (α, γ) on the surface of graphene oxide (GO) and was explored as an adsorbent material for simultaneous removal of thorium/uranium ions from aqueous solutions. In single component systems (Th(IV) or U(VI)), the α-GOM 2 (the weight ratio of GO/α-MnO 2 of 2) exhibited higher maximum adsorption capacities toward both Th(IV) (497.5 mg/g) and U(VI) (185.2 mg/g) than those of GO. In the binary component system (Th(IV)/U(VI)), the saturated adsorption capacity of Th(IV) (408.8 mg/g)/U(VI) (66.8 mg/g) on α-GOM 2 was also higher than those on GO. Based on the analysis of various data, it was proposed that the adsorption process may involve four types of molecular interactions including coordination, electrostatic interaction, cation-pi interaction, and Lewis acid-base interaction between Th(IV)/U(VI) and α-GOM 2 . Finally, the Th(IV)/U(VI) ions on α-GOM 2 can be separated by a two-stage desorption process with Na 2 CO 3 /EDTA. Those results displayed that the α-GOM 2 may be utilized as an potential adsorbent for removing and separating Th(IV)/U(VI) ions from aqueous solutions. [ABSTRACT FROM AUTHOR]

• The low valent Re complex in the reduction solution was in-situ analysis by EXAFS and UV–vis. • The hourglass crystal of Re was firstly prepared. • The speciation of Re in the hourglass cyrstal was low valent dimeric Re-DTPA by EXAFS and DET calculation. • The low valent Re in the hourglass crystal is stable in the air. This paper studied the fate of Re in the presence of polyaminocarboxy ligand (DTPA, EDTA and NTA) under reducing condition. When SnCl 2 as reducing agent, the results indicated the low valent Re was formed. And batch experiments studied the effect of pH and different ligands on the formation of low valent Re complex, the acid condition was favoured for the formation of low valent Re complex, and the order of complexing toward the low valent Re was the following: DTPA > EDTA > NTA. In the condition of pH = 1, DTPA as ligand, the hourglass crystal was obtained. Using ESI-MS, solid-state UV–Vis–NIR spectra, EXAFS, DFT calculation et al, the darkened patch of the hourglass crystal was demonstrated to be Re, and its speciation was dimeric Re 2 (μ-O) 2 DTPA. [ABSTRACT FROM AUTHOR]

• Chronic oral exposure to microcystin induced learning and memory deficits in mice. • MC-LR induced apoptosis of neurons, reduction of spine density in mice brain. • Prolonged exposure to MC-LR induced accumulation of Aβ and Tau-P in mouse brain. • MC-LR evidently increased the ratio of proBDNF/BDNF by reducing tPA expression. • MC-LR induced p-JNK, C-Jun expression and inhibited p-CREB, p-PKC expression. Previous studies have demonstrated that toxins produced by toxic cyanobacterial blooms are hazardous materials. Although microcystin-LR (MC-LR) has been revealed to inflict damage to the brain, the mechanisms underlying its neurotoxicity as a result of chronic exposure to MC-LR are not fully described. In this study, the mice were exposed to MC-LR dissolved in drinking water at doses of 1, 7.5, 15, or 30 μg/L for 180 days. MC-LR accumulated mostly in the mouse hippocampus (55 ng/g dry weight) followed by cortex (28 ng/g dry weight) after exposure to MC-LR at 30 μg/L. MC-LR exposure at this concentration induced dysfunction of learning and memory, accompanied with apoptosis of neuronal cells (with 10% reduction of the neurons in the CA1 region and 15% in the CA2 region), reduction of spine density, accumulation of β-amyloid plaques 1–42 (Aβ1-42), and enhanced phosphorylation of tau (p-tau) in the brain, which is characteristic of Alzheimer's disease (AD). These data indicate that MC-LR may induce AD-like pathology. Following prolonged exposure, MC-LR significantly upregulated the ratio of proBDNF to BDNF by downregulating the tPA levels, thereby activating downstream signaling pathways to improve the expression of p-JNK, and c-Jun while to inhibit the expression of p-Creb and p-PKC. This study uncovered new molecular mechanisms that account for neurotoxicity after chronic exposure to MC-LR, which has wide-ranging implications for public health. [ABSTRACT FROM AUTHOR]

In recent years, microplastics/nanoplastics (MPs/NPs) have received substantial attention worldwide owing to their wide applications, persistence, and potential risks. Wetland systems are considered to be an important "sink" for MPs/NPs, which can have potential ecological and environmental effects on the ecosystem. This paper provides a comprehensive and systematic review of the sources and characteristics of MPs/NPs in wetland ecosystems, together with a detailed analysis of MP/NP removal and associated mechanisms in wetland systems. In addition, the eco-toxicological effects of MPs/NPs in wetland ecosystems, including plant, animal, and microbial responses, were reviewed with a focus on changes in the microbial community relevant to pollutant removal. The effects of MPs/NPs exposure on conventional pollutant removal by wetland systems and their greenhouse gas emissions are also discussed. Finally, current knowledge gaps and future recommendations are presented, including the ecological impact of exposure to various MPs/NPs on wetland ecosystems and the ecological risks of MPs/NPs associated with the migration of different contaminants and antibiotic resistance genes. This work will facilitate a better understanding of the sources, characteristics, and environmental and ecological impacts of MPs/NPs in wetland ecosystems, and provide a new perspective to promote development in this field. [Display omitted] • Sources and characteristics of MPs/NPs vary in different wetland ecosystems. • Multiple factors determine the removal of MPs/NPs from wetland ecosystems. • MPs/NPs damage the flora and fauna of wetland ecosystems to various degrees. • MPs/NPs impact pollutant conversion and purification in wetland ecosystems. • The risk of MPs/NPs accumulation via the biological chain warrants concern. [ABSTRACT FROM AUTHOR]

A novel porous core-shell magnetic β-cyclodextrin/graphitic carbon nitride photocatalyst (Mβ-CD/GCN) was synthesized and employed in a solar light driven catalytic system for the degradation of polychlorinated biphenyls (PCBs). The Mβ-CD/GCN display superior photocatalytic performance on account of porous structure and ultrathin GCN nanosheets design, the former improves the utilization of visible light by multiple scattering and reflection of incident light, and the latter accelerates electron transfer. The ultrahigh specific surface area (1255 m2 g−1) of Mβ-CD/GCN provided a large number of active sites for adsorption and degradation of the target pollution. The pseudo-first order reaction rate constant (k obs) for the degradation of PCB180 by Mβ-CD/GCN was 0.021 min−1, which improved 3.23 times than the bulk GCN. Additionally, the effects of various reaction parameters and water matrices were studied on the degradation of PCB180. Three possible degradation pathways and mechanism of PCB180 were speculated according to the identification of reaction intermediates and detection of reactive species. The solar light driven Mβ-CD/GCN catalytic technology is a promising method not only for the control of persistent organic pollutants (POPs), but also the catalyst could be recovered and reused through simple magnetic separation. [Display omitted] • Degradation of PCB180 is achieved by porous core-shell Mβ-CD/GCN under solar light. • Ultrahigh specific surface area (1255 m2 g−1) of Mβ-CD/GCN provides great active sites. • PCB180 is gradually transformed into alcohols, ketones and fatty acids. • Chlorine atoms are removed from biphenyl and generate tetrachloroethylene. [ABSTRACT FROM AUTHOR]

As detriments in aquatic environments, microplastics (MPs) have been commonly studied on organisms, but tissue-scale effects of MPs were poorly understood. Discus fish (Symphysodon aequifasciatus), herewith, were exposed to polystyrene MPs (0/20/200 μg/L) for 28 d. We found that MPs significantly inhibited growth performance. MPs were observed in skin, gill and intestine after 14/28-d exposure. MPs bioaccumulation was independent of exposure time, but increased with MPs concentrations. Microbial community diversity of fish gill, but not skin and intestine, in MPs treatments was significantly increased. Bacterial community of MP-treated skin and gill were obviously separated from control. Skin dominant phyla changed from Actinobacteriota to Proteobacteria and Firmicutes. Proteobacteria gradually occupied dominance in gill after exposure. Furthermore, MPs-induced skin oxidative stress was demonstrated by the activation of superoxide dismutase and catalase. Skin malondialdehyde also increased and showed significant correlations with four bacterial phyla, e.g., Proteobacteria. Gill Na+/K+-ATPase activity decreased, strongly correlating to microbial community changes caused by MPs. Intestinal digestive enzymes activity (pepsin, lipase and α-amylase) reduced, revealing correlation with bacterial community especially Fibrobacterota. These results suggest a tissue-specific effect of MPs to microbial community and biomarkers in aquatic organism. [Display omitted] • MPs accumulated more in fish intestine than skin and gill. • MPs changed microbial community of skin and gill more than intestine. • MPs caused skin oxidative stress and intestinal digestive blockage. • Na+/K+-ATPase showed significant correlation with gill community. [ABSTRACT FROM AUTHOR]

A facile one-step pyrolysis method was employed to prepare an iron containing carbonaceous catalyst using coagulation waste (CW) from paper mill. The catalyst (noted as PMCW) was used to activate peroxymonosulfate (PMS) for decomposition of Reactive Red 2 (RR2). The degradation mechanism was analyzed by reactive oxygen species (ROS) scavenging experiments, electron spin resonance spectroscopy, electrochemical measurements, selective deactivation of the functional groups on the catalyst surface, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Results showed that, besides ROS (•OH, SO 4 •- and 1O 2), electron transfer pathways induced by −OH functional groups and the π-π* system are involved in the degradation mechanism of RR2. Concerning different decomposition pathways, seven intermediates were identified, and three important steps, including attack on the azo group, cleaving the N9−C10 bond, and opening the naphthalene ring, were deduced via application and analysis of quadrupole time-of-flight liquid chromatography/mass spectrometry (QTOF LC/MS) and density functional theory (DFT) calculations based on Fukui indices and electrostatic potential (ESP) distributions. This work not only provides a novel facile recycling strategy of industrial waste from paper manufacturing to good carbonaceous catalysts but also deepens the understanding of the mechanisms of PMS activation with carbonaceous materials. [Display omitted] • A novel Fe-containing carbonaceous catalyst (PMCW) was prepared using hazardous CW • Over 98% of RR2 removal was achieved in the PMCW/PMS system within 10 min reaction. • Both radical and non-radical take effect on RR2 degradation in PMCW/PMS system • Electron transfer induced by −OH and π-π* played a vital role in RR2 degradation • Analyses of QTOF LC/MS and DFT successfully reveal RR2 degradation pathway by PMCW [ABSTRACT FROM AUTHOR]

Methane emission has contributed greatly to the global warming and climate change, and the pollution of heavy metals is an important concern due to their toxicity and environmental persistence. Recently, multiple heavy metals have been demonstrated to be electron acceptors for methane oxidation, which offers a potential for simultaneous methane emission mitigation and heavy metal detoxification. This review provides a comprehensive discussion of heavy metals reduction coupled to methane oxidation, and identifies knowledge gaps and opportunities for future research. The functional microorganisms and possible mechanisms are detailed in groups under aerobic, hypoxic and anaerobic conditions. The potential application and major environmental significances for global methane mitigation, the elements cycle and heavy metals detoxification are also discussed. The future research opportunities are also discussed to provide insights for further research and efficient practical application. ga1 • Methane oxidation provides electrons for heavy metals reduction. • Microorganisms and responsible mechanisms are identified. • Potential application and key discussions are provided. • The environmental significances for methane and elements cycle are described. • The perspectives for mechanism, bioremediation and application are discussed. [ABSTRACT FROM AUTHOR]

• 4 μm and 10 μm PS-MPs could accumulate in testis of mice. • Sperm quality and testosterone level of mice were declined after exposure to 0.5 μm, 4 μm, and 10 μm PS-MPs. • PS-MPs induced testicular inflammation and the disruption of blood-testis barrier. Microplastics (MPs) have become hazardous materials, which have aroused widespread concern about their potential toxicity. However, the effects of MPs on reproductive systems in mammals are still ambiguous. In this study, the toxic effects of polystyrene MPs (PS-MPs) in male reproduction of mice were investigated. The results indicated that after exposure for 24 h, 4 μm and 10 μm PS-MPs accumulated in the testis of mice. Meanwhile, 0.5 μm, 4 μm, and 10 μm PS-MPs could enter into three kinds of testicular cells in vitro. In addition, sperm quality and testosterone level of mice were declined after exposure to 0.5 μm, 4 μm, and 10 μm PS-MPs for 28 days. H&E staining showed that spermatogenic cells abscissed and arranged disorderly, and multinucleated gonocytes occurred in the seminiferous tubule. Moreover, PS-MPs induced testicular inflammation and the disruption of blood-testis barrier. In summary, this study demonstrated that PS-MPs induced male reproductive dysfunctions in mice, which provided new insights into the toxicity of MPs in mammals. [ABSTRACT FROM AUTHOR]