Search

[Display omitted] • Schwertmannite and sulfated polysaccharides are selectively recovered from AMD. • This method involves pH-controlled Fe biomineralization and sulfate bioreduction. • Solution equilibrium calculation characterizes the Fe biomineralization behavior. • The key factor that determines the pH required for Fe biomineralization is revealed. • The recovered sulfated polysaccharides show the obvious antiangiogenic bioactivity. Acid mine drainage (AMD) poses an environmental challenge to the global mining industry. However, it is also a potential source of iron and sulfate for recovery. In this work, we proposed an integrated process of pH-controlled biomineralization of iron and biological sulfate reduction to facilitate the concurrent purification of AMD and selective recovery of iron and sulfate as valuable products. Compared with the biomineralization controlling pH at 2.8, the modified biomineralization controlling pH at 3.2 improved the iron precipitation efficiency from 9.7 % to 95.3 %, leading to a 53–fold increase in pure-grade schwertmannite Fe 8 O 8 (OH) 4.08 (SO 4) 1.96 production in AMD. This improvement may be related to the relatively low Gibbs free energy value of the Fe3+ mineralization reaction at pH 3.2. The solution equilibrium calculation using Visual MINTEQ indicated that keeping the system pH at an appropriate level is crucial for the spontaneous and effective biomineralization of Fe to schwertmannite at room temperature. The specific pH required for Fe biomineralization is slightly affected by the content of metal cations (e.g., Al3+, Ca2+, Mg2+, Cu2+, and Mn2+) and oxoanion (AsO 3 3−/AsO 4 3−) in AMD but greatly affected by sulfate content (mM) (pH = 0.149 ln c(SO 4 2−) + 2.551). For the effluent resulting from AMD biomineralization, sulfate reduction at pH 5.0 removed residual Zn2+ (99.9 %), Mn2+ (97 %), Cu2+ (100 %), and sulfate (87.1 %) while recovering sulfated polysaccharides with antiangiogenic bioactivity (as confirmed by the chorioallantoic membrane tests). The pilot-scale continuous flow operation experiments demonstrated that this integrated method has the potential to recover valuable iron/sulfate products from AMD. [ABSTRACT FROM AUTHOR]

[Display omitted] • Double-jacketed agitated crystallizer is an emerging technique of zero-liquid discharge. • ∼90 % of sulphate has been removed and recovered as gypsum from tannery RO reject. • XRD results of recovered CaSO 4 are 95 % identical to commercial gypsum. • Process temperature favors the irreversible reaction. • Nucleation and growth rate occur at room temperature as an inverse trend. This present study has assessed the resource recovery of tannery RO reject wastewater using crystallization in a double-jacketed agitated crystallization reactor under batch performance. The main objectives of this process were to remove sulphate from tannery RO reject wastewater and to recover the product as gypsum crystals. In the primary stage of initiator in crystallization, the CaCl 2 initiator has better results in recovering the gypsum crystals involving chemical reactions. SEM, XRD, FTIR, and optical microscope characterize the product gypsum crystals. XRD results revealed that the uninformative size of gypsum crystals ranged between 54.61 and 61.86 nm, respectively. The experimental investigation on pH (4–12), temperature (30–180 °C), and reaction time (30–150 min) was performed. The maximum removal of sulphates from tannery RO reject wastewater was found to be 90–94 % under ideal pH 7, 30 °C for 30 min of reaction time, and 85–90 % gypsum crystal recovery, respectively. Moreover, gypsum cum Plaster of Paris was also investigated since interlocking structure and intercrystallite interactions can improve mechanical strength. It can be utilized for construction materials and ceramic mouldings for real-time applications. It could be concluded that the crystallization study helps in combating the harmful effects caused by occupying landfill sites and environmental damages. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sulfate anions and calcination successfully introduced Vo into Co-SLDO/CN; • LDOs and CN composites were first used in the photo-assisted PMS catalytic system; • Carbamazepine was completely eliminated within 10 min; • Singlet oxygen was the primary active species in the PMS + visible light system. Improving the utilization rate of active sites through rational design of material structure is considered to be an effective way to enhance the activation efficiency and degradation performance of peroxymonosulfate (PMS). Co-sulfate anions-induced layered double oxide/carbon nitride (Co-SLDO/CN) was prepared by sulfate anion induction for the rapid degradation of carbamazepine in the photo assisted persulfate system. Graphitic carbon nitride (CN) provided nucleation sites for Co-SLDH to inhibit its aggregation. Sulfate anions induced the material to transform into three-dimensional flower balls, promoting the formation of oxygen defects, which is beneficial for charge separation and thus promotes more electrons to participate in the catalytic reaction. The synergistic effect of visible light/PMS system and oxygen vacancies (Vo) enabled 100 % degradation efficiency of 10 mg/L carbamazepine (CBZ) to be achieved within 10 min. Among them, the electron transfer of Co (III)/Co (II) promoted the decomposition of PMS to generate SO 4 -•, visible light activated Co-SLDO/CN to produce e CB - and h VB +, and the O 2 in the micro area around the oxygen vacancy captured electrons to generate O 2 •− and 1O 2. Seventeen intermediates, such as 10, 11-dihydroxy-carbamazepine, and possible CBZ degradation pathways were proposed, and the overall toxicity was found reduced through experiments, which was consistent with eco-SAR software prediction. After four cycles, the degradation rate of CBZ remained at 100 %, and the system showed good efficiency while degrading various PPCPs, indicating practical application potential. [ABSTRACT FROM AUTHOR]

• The thermal stability of HA-based systems was investigated through calorimetry. • Damköhler (Da) and dimensionless heat of reaction (B) were assessed for all mixtures. • Reactor stability diagram Da-B was formulated, distinguishing the safe operating zone. • Mixtures containing salts could stabilize hazardous molecules. • At the initial temperature of 300 K, the inherently safe zone is achieved for B < 10. The thermal instability of hydroxylamine (HA) poses severe concerns in the process industry, while preventive and mitigative strategies are required to reduce the frequency and magnitude of associated decomposition phenomena. From this perspective, formulating an aqueous solution or using derived salts could be a solution for risk reduction. Nevertheless, the effect of HA-derived salt addition on HA/water solutions has yet to be reported in the literature. For this reason, the scope of the present work is to examine experimentally whether salt addition can reduce the occurrence and severity of HA thermal degradation. Samples containing HA and hydroxylamine sulphate (HAS) or hydroxylamine hydrochloride (HH) were analysed. During the experimental campaign, a calorimeter was used for the assessment of reaction kinetic, thermodynamic, and onset features. The determined parameters were used for safety purposes to understand the related thermal hazards and to provide stability diagrams. The results show, under certain conditions, that the type and amount of HA-derived salt determines an attenuation of the decomposition of HA/water solutions. Moreover, increasing the amount of salt enhances the susceptibility to decomposition of the HA/water solution, while lower salts content could help stabilise the HA mixtures. According to the developed stability diagram, an inherently safe zone for reaction or storage has been established. Eventually, the proposed structured approach can be intended as a strategic procedure to involve the reaction parameters gathered, which is helpful for drawing general guidelines for establishing safer processes and reaction conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Characterization of phosphogypsum and optimization of sulfate leaching. • Selection and evaluation of sulfate-reducing-bacterial consortia under challenging conditions. • High reduction of sulfate leached from PG in batch bioreactor with the isolated consortium. Phosphogypsum (PG) is generated annually from phosphoric acid production. This by-product contains 50% of sulfate (SO 4 2−), which can be recycled biologically. Biorecovery of elemental sulfur (S 0) involves firstly converting SO 4 2− into biogenic sulfide using sulfate-reducing bacteria under anaerobic conditions, then oxidizing the sulfide produced into S 0 using sulfur-oxidizing bacteria. This study focused on selecting and evaluating natural microbial consortia from SO 4 2− rich biotopes for their application in the initial first step of S 0 biorecovery. The PG sample was first comprehensively characterized using ICP-MS/OES, XRD, FTIR, and TGA analyses. Subsequently, SO 4 2− leaching optimization was performed through a design of experiments approach. The analysis revealed that CaSO 4 was the major component of the PG (78%), and the optimal parameters for leaching of SO 4 2− from PG were at a NaOH concentration of 7.4% and PG concentration of 158 g.L−1. Furthermore, the MYC-consortium isolated from a hydrothermal niche demonstrated the highest reduction capacity among the studied consortia. It also exhibited the highest performance under SO 4 2− concentrations up to 3.5 g.L−1, salinity levels up to 30 g.L−1, and in the presence of 60 ppm of Zn(II), 3 ppm of Cd(II), and 6 ppm of Pb(II). Moreover, this consortium showed a high capacity for reducing SO 4 2− in the bioreactor (90% after 6 weeks) when utilizing SO 4 2− from the PG-leached solution, as attested by the chemical analyses of the precipitate formed in the bioreactor. This research offers a comprehensive insight into the potential of MYC-consortium to convert leached SO 4 2− from PG into sulfide, which is the most critical step in the S 0 -biorecovery. [ABSTRACT FROM AUTHOR]

[Display omitted] • The increase of SO 4 2– loading enhanced the Sb(V)- and total Sb- removal. • 90% Sb(V) removal flux (0.76 g/m2·day) was achieved due to the input of sulfate. • The exposure of nitrate led to Sb 2 S 3 oxidation coupled to NO 3 – reduction. • Sulfide was produced microbially as the reductant for Sb(V) removal. • The mechanisms of biofilm action exposed to oxidized Sb, S, and N were summarized. Sb is classified as a priority pollutant, to control the pollution in aquatic environments of Sb, enhance the understanding of Sb biogeochemical cycle, the effects of sulfate and nitrate on antimonate (Sb(V)) removal in a Hydrogen-Based Membrane Biofilm Reactor (H 2 -MBfR) were investigated. With the input of sulfate, the MBfR achieved 90% Sb removal and a removal flux up to 0.76 g Sb/m2·day. The Sb(V) was reduced to Sb(III), which was primarily Sb 2 S 3 solids retained in the biofilm. Furthermore, the mechanism of antimonate reduction shifted from enzymatic reduction with no sulfate input to abiotic reduction based on sulfide produced microbially being the reductant. The subsequent input of nitrate suppressed Sb(V) reduction and removal, along with suppressing sulfate reduction. Nitrate became the dominant electron acceptor, which led to Sb 2 S 3 oxidation and the net release of Sb(V) and SO 4 2-. This work reinforces that the H 2 -MBfR is a promising bioremediation strategy for antimonate removal, and it provides mechanistic insights regarding the impacts of sulfate and nitrate on antimonate reduction and removal. [ABSTRACT FROM AUTHOR]

[Display omitted] • rSBR improve sulfate removal by upregulating dissimilated sulfate reductase. • Bioaugmentation with immobilized rSBR accelerates the metabolism of sulfate. • rSBR remove heavy metals via coprecipitation. • Bio-AnMBR removes approximately 99.4% of sulfate and 95.6% of metal removal. Sulfate-rich metal-laden wastewater (SRMLW) shows a significant threat on the ecological environment and human health. Sulfate-reducing bacteria (SRB) can remove sulfate from wastewater in anaerobic membrane bioreactor (AnMBR). This study constructed recombinant genetic engineered SRB (rSRB) and investigated the sulfate and heavy metals removal efficiency for treating SRMLW by immobilized-microbial bioaugmentation using rSRB (IMrSRB) coupled with AnMBR (Bio-AnMBR). The results show that Bio-AnMBR removed sulfate (99.4%) from SRMLW by upregulating key genes (Sat , DsrAB , AprAB , QmoABC , DsrC and DsrMKJOP) and enzymes (APS reductase, Dissimilatory sulfite reductase, Trithionate reductase and Thiosulfate reductase) in dissimilatory sulfite and sulfate respiration processes. Bio-AnMBR achieved synergistic biodegradation of sulfate and nitrogen by stimulating the activity of these bacteria related to the conversion of nitrogen and sulfate. Microbial analysis indicated that the relatively high abundance of rSRB (79.2%) and functional genes (70.1%) upregulated the activities of key enzymes associated with sulfate metabolism system, thus increasing the production of S (66.4 mg/L) and H 2 S (23.8 mg/L). Bio-AnMBR significantly improved the tolerance to heavy metals by increasing concentrations of CO32–, S2-, and HS-, which was configured to reduce heavy metals (95.6%) via precipitation of metal sulfide (81.3 mg/L), metal carbonates (30.7 mg/L) and metal hydroxides (18.7 mg/L). Bio-AnMBR increased system stability, shorted hydraulic retention time (HRT), decreased the production of soluble microbial products (SMP), extracellular polymeric substances (EPS) and waste-sludge production (WSP), as well as improved effluent quality. In conclusion, data in this study indicate that application of Bio-AnMBR is a feasible strategy for the treatment of SRMLW. [ABSTRACT FROM AUTHOR]

[Display omitted] • Intensification of SR-AOPs in wastewater effluents was assessed. • Combination of PMS with H 2 O 2 and O 3 showed positive effects on disinfection. • In PMS/H 2 O 2 /UV-A, the predominant radical depended on the oxidant molar ratio. • •OH is predominant in a molar ratio 1:1, and SO 4 •- in a ratio 1:3 (PMS:H 2 O 2). • The treatments are able to remove simultaneously different bacteria strains. This research addresses the application of advanced oxidation processes (AOPs) for wastewater reclamation at pilot scale, one of the main limitations usually observed in this type of technology. Although interest in sulfate radical-based AOPs (SR-AOPs) has increased considerably in recent years, pilot-scale application studies are very scarce. The generation of free radicals by activation of peroxymonosulfate (PMS) can be enhanced by the introduction of UV-A radiation, or other oxidants such as hydrogen peroxide (H 2 O 2) or ozone (O 3), increasing the efficiency of the processes with lower reagent consumption. The combination of 0.5 mM PMS and 0.25 g·h−1 O 3 was the fastest process in inactivation of Enterococcus faecalis , achieving inactivation in less than 45 min. Significant synergies were also observed for the combination of PMS, H 2 O 2 and UV-A radiation, achieving total inactivation in less than 120 min, a performance significantly lower than that of the PMS/O 3 system. Mechanistic studies showed that the sulfate radical (SO 4 •-) was responsible for bacterial inactivation in the PMS/O 3 system, while in the PMS/H 2 O 2 /UV-A system the predominant species varies according to the molar ratio of the oxidants. Thus, the hydroxyl radical (•OH) is predominant in a 1:1 ratio, and SO 4 •- is predominant in a 1:3 ratio. This phenomenon occurs because an excess of PMS acts as a sink for radicals, preventing their interaction with bacteria. The treatments studied have been shown to be effective in the simultaneous elimination of several pathogenic microorganisms such as Enterococcus faecalis , Escherichia coli, and Staphylococcus aureus , making this technology an alternative to conventional disinfection treatments. [ABSTRACT FROM AUTHOR]

[Display omitted] • Filamentous bacteria and electroactive bacteria (EAB) enhance mass transfer. • Adding L. varians GY32 promotes sulfate reduction in sediments. • L. varians GY32 conduces to enriching filamentous bacteria and EAB. • L. varians GY32 conduces to enriching SRB with increasing the abundance of dsrA. • Filamentous bacteria, EAB and SRB jointly promote sediment homogenization. Electron transfer and mass transfer are critical processes for efficient sediment remediation using sediment microbial electrochemical systems (SMESs). Increasing reports show that filamentous electroactive microorganisms (f-EAMs) that widely exist in heterogeneous sediments play essential roles in biogeochemical cycles and sediment remediation, significantly impacting process efficiencies. However, the knowledge of the mechanism of f-EAMs in biogeochemical cycles and sediment remediation is still limited. This study investigated the spatiotemporal effect of a unicellular Gram-positive f-EAM, Lysinibacillus varians GY32, on the sulfur cycle in SMESs. The results showed that adding L. varians GY32 into sediments could significantly decrease the diffusion resistances of the sediments by up to 49.4% and reduce the porewater sulfate concentrations by up to 46.4%, which validated that L. varians GY32 contributed to enhancing the mass transfer and sulfate reduction in sediments. Meanwhile, the vertical difference in diffusion resistances and porewater sulfate concentrations was reduced. The dynamics of electrochemical and physicochemical properties of sediments coincided well with the enrichment of filamentous microorganisms, sulfate-reducing bacteria, EAMs (especially f-EAMs), and syntrophic bacteria, as well as the reinforcement of the community interactions that took the above microorganisms as core members. Our findings provide novel insights for understanding the underlying mechanism of f-EAMs in biogeochemical cycles and sediment remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co 3 O 4 @CN heterojunction was constructed by in situ growth and annealing. • In situ growth facilitated the formation of defective CN and low-valent Co2+. • In situ growth promoted the hydrophilicity and adsorption capacity. • In situ growth induced SO 4 •− proliferation as the dominant ROS for CIP oxidation. Metal-organic frameworks (MOFs)-derived catalysts have attracted growing attention for wastewater decontamination. However, the design of effective catalysts for the generation of on-demand reactive oxidative species (ROS) from peroxymonosulfate (PMS) remains challenging. Herein, we prepared hollow Co 3 O 4 confined in g-C 3 N 4 (CN) through in situ growth of ZIF-67 (Co 3 O 4 @CN). Characterizations revealed that this unique route endowed mesoporous Co 3 O 4 @CN with good hydrophilicity, thus promoting its adsorption capacity towards both pollutants and PMS. Furthermore, Co 3 O 4 @CN demonstrated high activity for fast ciprofloxacin (CIP) degradation. The heterojunction between Co 3 O 4 and defective CN, and the abundant active sites (Co2+) formed during in situ growth remarkably facilitated SO 4 •− generation as the dominant species for CIP oxidation. Two possible pathways for CIP mineralization were proposed. Theoretical and experimental investigation indicated that the toxicity of the intermediates could be attenuated by deep mineralization. This work provides profound insights into engineered MOFs-derived catalysts for fast wastewater mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • SR-AOP pre-treatment results in high SO 4 2− ions and partial DOC/COD removal. • Post-biofiltration with petroleum coke and sand successfully attenuated DOC/COD. • Anaerobic degradation of organics in peat was followed by methylotrophy in sand. • Slow sulfate removal was potentially linked to C(1)-sulfur compounds metabolism. Fate of dissolved organics and sulfate ions was studied in fixed bed biofilters (FBBs) treating pre-treated oil sands process water (OSPW) in the presence of industrially relevant substrates namely petroleum coke (PC) and sand. For pre-treatment, the solar-activated sulfate radical advanced oxidation process (SR-AOP) was performed using 2.5 and 5 mM peroxymonosulfate (PMS) as a precursor with solar irradiation of 119.5 W h m−2. Excellent degradation of naphthenic acids (NAs) was attained by SR-AOP, attaining 88 % and 97 % total NAs after 9 h of treatment at 2.5 and 5 mM of PMS, respectively. However, the treatment increased the toxicity due to byproducts and metabolites following the poor removal of dissolved organics, i.e., 13 % and 21.5 %, respectively. Electron paramagnetic resonance spectrometry (EPR) analysis exhibited that hydroxyl radical (⋅OH) and singlet oxygen (1O 2) were the predominant active species produced during SR-AOP. The post-treatment biofiltration improved the mineralization of dissolved organics (45 %) and NAs (99 %) as well as removed the residual toxicity (>80 %). Taxonomy-based transcriptomics analyses (RNA) confirmed the enrichment of microbes involved in the degradation of hydrocarbons and carboxylic acids, methylotrophy, and potentially C(1)-sulfur compounds metabolism. Scanning electron microscopy with energy-dispersive X-ray spectroscopy indicated the potential of PC to support sulfur deposition, but at slower rates. This study indicates that the produced water can be efficiently reclaimed by using advanced oxidation and biofiltration approaches. [ABSTRACT FROM AUTHOR]

The simple synchronous introduction of sulfate and RuO x into CeO 2 improved its activity, selectivity and durability for catalytic combustion of chlorinated VOCs due to the balancing redox-acidity. [Display omitted] • Simultaneous modification of CeO 2 with sulfate and RuO x by simple co-precipitation. • The redox-acidity properties of modified catalyst construct the optimal balance. • Ru-CeO 2 -S 0.05 exhibit optimal activity, selectivity and stability of DCE oxidation. • Modified catalyst own excellent chlorine-removability and versatility (multi-VOCs). • Modified catalyst provide a new sulfate-organic complex intermediate pathway. CeO 2 -based catalysts are highly active but easily deactivated for the catalytic combustion of chlorinated VOCs (CVOCs), and enhanced redox and acidity are also considered to be effective strategies. However, the screening of practicable modifiers and their preparation method to achieve the promotion and balancing of redox-acidity is still desired. In this work, sulfate and RuO x were simultaneously introduced into CeO 2 by a simple co-precipitation method, and the optimal redox-acidity was constructed. The catalytic combustion of 1,2-dichloroethane (DCE) indicated that 2.5Ru-CeO 2 -S 0.05 presented an outstanding oxidation activity and selectivity of chlorinated byproducts and superior cycle and long-term stability (at least 60 h at 280 °C), even in the presence of 5 % H 2 O. A series of control experiments, such as the introduction methods, the precursors and contents of Ru and sulfate, and their property characterization revealed that the bulk doping of Ru mainly contributed to the promoted activity and durability through more exposed Ce3+/4+ and oxygen vacancies and the rapid removal ability of the inorganic chlorine species via a semi-Deacon reaction pathway, as well as to the formation of chlorinated byproducts. Meanwhile, the synchronous introduction of sulfate as Brønsted acid sites efficiently inhibited these chlorinated byproducts, while its retained redox ability and the enhanced Lewis acid sites owing to the strong electron withdrawing of the sulfate also further promoted DCE oxidation. Moreover, 2.5Ru-CeO 2 -S 0.05 showed a high activity and excellent durability for the catalytic oxidation of ethylene, vinyl chloride and their mixtures with 1,2-DCE. This work provided a demonstration for balancing the oxidation performance and acidity of CeO 2 -based catalysts, which contributed to the development of applicable catalysts for catalytic oxidation of CVOCs under actual working conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Summary of the classification and preparation strategies of MOFs-derived CMs. • Summary of mechanisms of PDS/PMS activation by MOFs-derived CMs. • Combination and transformation of the radical and non-radical pathways. • Future challenges and research directions related to MOFs-derived CMs. With the increasing challenges of environmental pollution, the sulfate radical-based advanced oxidation processes (SR-AOPs) have received increasing attention owing to their high efficiency and environment-friendliness. The future development of SR-AOPs depends on the development of new catalysts with high activity and stability. Various Metal – organic frameworks (MOFs) derived carbon-based materials (CMs) with unique physical and chemical properties have been prepared by pyrolyzing MOFs, which have been provn to show excellent performance in SR-AOPs and become a rapidly expanding research field. Herein, to clarify the application advances of MOFs-derived CMs in SR-AOPs, we have summarized the classification, synthesis strategies, and corresponding characteristics of MOFs-derived CMs. In addition, the mechanisms related to the activation of PDS/PMS for organic degradation by MOFs-derived CMs are outlined. Moreover, the bottlenecks, application prospects of MOFs-derived CMs are briefly summarized. This review aims to elucidate the recent trends and critical mechanisms of MOFs-derived CMs applied in SR-AOPs, offering new insights for the further design of MOFs-derived CMs and organic pollution remediation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fundamental kinetics parameters of UV 254 and radical-induced DNA damage. • Intracellular and extracellular degradation kinetics increased with qPCR amplicon length. • ARG degradation rate increases with the number of AT bps and intrastand 5′-TA-3′ content in qPCR amplicons. • ampR deactivation rate by bacterial transformation faster than measured degradation rate by qPCR. • Longer qPCR amplicons as indicators of ARGs treatment efficiencies. The environment has been implicated with antibiotic resistance (AR). Effective degradation and deactivation of antibiotic resistance genes (ARGs) in wastewater treatment can serve as barriers to AR dissemination. This study investigated the degradation kinetics of intracellular (i-) and extracellular (e-) plasmid-encoded tetA , ampR and sul1 ARGs using UV 254 , hydroxyl radical (HO.) and sulphate radical (S O 4. - ) UV-based advanced oxidation processes (UV 254 /H 2 O 2 and UV 254 /S 2 O 8 2- respectively). The degradation of tetA , ampR and sul1 was quantified using quantitative polymerase chain reaction (qPCR). The damages to each ARG were observed using two qPCR amplicons ranging between 162 and 1054 bp. Culture-based horizontal gene transformation experiments were used to estimate the deactivation kinetics of pCR™2.1-TOPO AR plasmid. ARG degradation and deactivation kinetics were then compared to understand the roles of each treatment strategy in AR mitigation. Results indicate that extracellular ARGs degradation kinetics of the treatments followed an order UV 254 /S 2 O 8 2- > UV 254 /H 2 O 2 > UV 254. The base pair specific kinetic constants with respect to HO. and S O 4. - at pH 7 were between 1.86 × 109-1.65 × 1011 M−1s−1 and 2.87 × 109-5.84 × 1011 M−1s−1 respectively. e-ARGs degradation was at least 2-fold higher than i-ARGs degradation for all treatments. UV 254 /S 2 O 8 2- was most effective for ARG degradation under acidic pH (5–6) while UV 254 /H 2 O 2 was most effective between pH 7 and 8. Higher degradation rates were recorded for AT-rich ampR and longer qPCR amplicons. Deactivation rates by UV 254 /H 2 O 2 and UV 254 /S 2 O 8 2- were 2.6-times higher than that of UV 254. Generally, deactivation kinetics were ∼ 8–13 times faster than degradation kinetics observed for short ampR amplicon. These findings show an overestimation of the potential risks of ARG presence using short qPCR target amplicons and the impact of nucleotide composition on ARG damage. [ABSTRACT FROM AUTHOR]

[Display omitted] • The maximum VFA production was 516 ± 6.0 mg COD/g VSS through AES pretreatment. • Sludge solubilization and hydrolysis were dramatically enhanced. • AES had a positive effect on municipal ES acidification process. • AES pretreatment severely inhibited microbial communities related to methanogenesis. • AES was highly biodegradable but not a substrate for VFA production. The conventional approach of anaerobic fermentation of excess sludge (ES) to produce volatile fatty acids (VFA) is limited by its poor efficiency and secondary pollution. Herein, a new strategy was developed for improving VFA production from the ES by sodium alcohol ether sulphate (AES) pretreatment. A maximum VFA yield of 516 ± 6.0 mg COD/g VSS was obtained with 0.28 g AES/g SS. It was proved that AES pretreatment had a synergistic effect on the enhancement of ES flocs solubilization, as well as hydrolysis and acidification of organic compounds in the ES. Meanwhile, the hydrolytic and acid-producing bacteria (i.e., Actinobacteria and Firmicutes) were enriched, while the VFA consumers (i.e., Halobacterota) were reduced by AES pretreatment, which resulted in the improved efficiency of VFA accumulation. Thereby, the AES had a positive effect on the conversion of organic matters in the ES to VFAs. Additionally, up to 97% of added AES could be degraded naturally during the treatment process, relieving the secondary pollution to environment. The strategy of AES pretreatment proposed in this work may provide a viable approach for ES treatment and relatively low-cost recovery of waste biomass. [ABSTRACT FROM AUTHOR]

[Display omitted] • Effective degradation of dissolved organics in produced water by solar activated SR-AOPs. • SO 4 •−, •OH and 1O 2 reactive species were formed during solar activated SR-AOPs. • Better performance by solar activated peroxymonosulfate compared to persulfate. • Excellent mineralization of dissolved organic by post-treatment biofilm filtration. • Microbial profiling indicated presence of hydrocarbons and carboxylic acid degraders. This study reported for the first time the potential of sequential solar activated sulfate radical advanced oxidation processes (SR-AOPs) and fixed bed biofiltration for the enhanced remediation of dissolved organics in oil sands process water (OSPW). The effect of initial sulfate precursors namely persulfate (PS) and monopersulfate (PMS) was examined on the degradation of naphthenic acid (NA) surrogates and various classes of organics in real OSPW. Effluents from solar activated SR-AOPs treatment of OSPW at specific conditions were subjected to biofiltration for 45 days. Fast and complete degradation of 5-phenylvalveric acid (PVA) and up to 99% degradation of various organics in OSPW were achieved by the solar activated SR-AOPs. Radical scavenger and spin-trap electroparamagnetic spectrometry analysis showed that hydroxyl (•OH) and sulfate (SO 4 •−) radicals were the major reactive species generated and participated in the oxidation of organics in SR-AOPs treatment with either PS or PMS along with a small proportion of singlet oxygen. The biofiltration post-treatment showed significant mineralization of dissolved organics in treated OSPW, achieving over 60% and 40% reduction in DOC and COD, respectively, surpassing most of the reported studies for such combined approach. The bacterial metataxonomic analysis indicated significant enrichment of hydrocarbons and carboxylic acid degraders (Sphingomonas and Sphingopyxis) in the biofilters treating PMS pre-treated OSPW. However, for biofilters treating raw OSPW and PS, the bacterial community was dominated by hydrocarbon degraders and methanotrophs. The treated OSPW was found completely non-toxic for the OSPW treated with PMS-9 h and biofiltration. This demonstrates the potential of combined treatment for the effective remediation of the oil sand industry effluent. [ABSTRACT FROM AUTHOR]

[Display omitted] • The combination technology of SR-AOPs and membrane filtration (MF) was summarized. • The current scenario of various integrated catalytic filtration membranes methods was centralized. • SR-AOPs/MF was used to remove pollutants and reduce membrane fouling. • The future opportunities and challenges of this technology are discussed. Integration of membrane filtration (MF) and sulfate radical-advanced oxidation processes (SR-AOPs) has progressively attracted extensive attention for environmental remediation because of simultaneous degradation and filtration of pollutants in wastewater. Current development of the integration of MF and SR-AOPs can be divided into three main categories: (1) peroxymonosulfate (PMS)/peroxydisulfate (PDS) are activated by membrane materials to achieve the purpose of synergistic oxidation-filtration process; (2) removal of contaminants was achieved by filtering through the membrane, and then adding PMS/PDS to regenerate the membrane; (3) the membrane can be directly used as an oxidant-catalyst/water contactor to promote SR-AOPs. On this basis, this review comprehensively summarizes the classification, preparation methods and properties of different types of membrane-based materials and filtration devices. In addition, the antifouling effect and self-purification regeneration ability of different SR-AOPs systems on the membrane are highlighted. Moreover, the main mechanisms including the analysis of active sites, the generation of free radicals, and the theoretical calculations in integration of MF and SR-AOPs are defragmented and discussed. Finally, the technical challenges of coupling technology in wastewater treatment are discussed, and the development and application prospects of the collaborative mixing process are prospected. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pretreatment with 0.1 g/g TSS KMnO 4 reduced H 2 S yield from WAS to 67%. • KMnO 4 inhibited sulfur containing organics hydrolysis and sulfate reduction. • KMnO 4 addition changed the chemical equilibrium of sulfide species. • KMnO 4 decreased the related abundances of S2− producers and functional genes. Potassium permanganate, a versatile strong oxidant, has been applied as a highly effective additive to degrade pollutants and recover resources from Waste activated sludge (WAS). In addition to these benefits, it was observed in this study that KMnO 4 largely reduced H 2 S production from WAS anaerobic fermentation. With an increase of KMnO 4 dosage from 0 to 0.1 g/g TSS, the maximal H 2 S production reduced from 292.3 × 10−4 to 96.4 × 10−4 mg/g VSS while the maximal short-chain fatty acids production increased from 23 to 251 mg COD/g VSS. Model-based analysis showed that KMnO 4 decreased the maximal H 2 S yield potential and H 2 S production rate. The mechanism explorations revealed that several oxidative substances (e.g., •O 2 − and •OH), Mn2+, and O H - were substantially generated after KMnO 4 being added into the fermenters. The generated oxidative substances resulted in intracellular substance release even cell apoptosis. This inhibited the activities of two main S 2 - (H 2 S precursor) producers, i.e., Sulfate reducing bacteria (SRBs) and anaerobes responsible for hydrolysis of sulfur-containing organics, especially that of SRBs. Experimental results showed that 0.1 g/g TSS KMnO 4 inhibited sulfur-containing organics hydrolysis, amino acids degradation, and sulfate reducing process by 12.5%, 27.2%, and 61.2%, respectively. The Mn2+ released from KMnO 4 and other metal ions (e.g., Fe2+) originated from metal-binding functional groups owing to KMnO 4 addition caused substantial S-based precipitations, which also decreased S 2 - in the fermentation liquor. Besides, the generated O H - increased fermentation pH, which benefited the chemical equilibrium of sulfide species from H 2 S to H S - and S 2 - . Microbial community and PICRUSt2 analyses further revealed that KMnO 4 significantly decreased the abundances of S 2 - producers and functional genes responsible for sulfate reducing process. [ABSTRACT FROM AUTHOR]

[Display omitted] • A host-guest Z-scheme g-C 3 N 4 /BiPO 4 (CNB x) photocatalyst was successfully fabricated. • CNB x could in-situ activate the SO 4 2−, H 2 O and O 2 in organic wastewater simultaneously. • The degradation rate of BPA with SO 4 2− addition was 50% higher than that without SO 4 2−. • The produced SO 4 ·−, ·OH and O 2 ·− contribute to the degradation of organic pollutants. In recent years, the excellent performance of sulfate radical (SO 4 ·−) in advanced oxidation process has attracted more and more attention. However, it requires the consumption of expensive persulphate (PMS/PDS), and the resulting sulfate ion (SO 4 2−) requires subsequent processing procedures, which limits its practical application value. In this work, a Z-scheme heterojunction g-C 3 N 4 /BiPO 4 (CNB x) photocatalyst was constructed to in-situ activate the residual SO 4 2− , H 2 O and dissolved O 2 in organic wastewater simultaneously and produce SO 4 ·−, ·OH and O 2 ·− efficiently, so as to realize enhanced organic pollutant treatment by using clean and renewable solar energy resources. Under the condition of 10 mM SO 4 2− addition and 100 mW·cm−1 illumination, the degradation rate of BPA (C 0 = 20 mg·L−1) by optimized CNB 150 catalyst was 0.30 min−1, which was 50% higher than that without SO 4 2− (0.20 min−1). Detailed characterizations shown that a direct Z-scheme heterojunction was formed between g-C 3 N 4 and BiPO 4 , which could be simultaneously stimulated by light, and then effective charge separation and migration could be achieved through the internal electric field caused by the Fermi-level difference between the g-C 3 N 4 (-0.12 eV) and BiPO 4 (0.01 eV). In general, this study makes full use of renewable solar energy and provides a feasible path for promoting the simultaneous in-situ utilization of small molecules (SO 4 2−, H 2 O and O 2) that originally exist in water, which makes organic wastewater treatment more economic, eco-friendly and sustainable. [ABSTRACT FROM AUTHOR]

[Display omitted] • Acidic MIWs with high SO 4 2- content were mitigated by SRB at low temperature. • MIWs were neutralized by alkalinity generated in a sulfidogenic bioreactor. • High SRRs at low temperature were achieved. • Relative abundance of SRB increased during treatment of actual MIWs. • Metals in actual MIWs were removed by off-line or in-line precipitation. The aim of this study was to develop a biological method for the simultaneous removal of sulfate and metals from acidic low-temperature mining effluents. A mixed consortium of cold-tolerant sulfate-reducing bacteria (SRB) and other microorganisms was immobilized on glass beads and exploited in an up-flow biofilm reactor for the continuous treatment of actual and synthetic mining-impacted waters (MIWs) with initial sulfate concentrations between 1580 and 5350 mg L-1. The proton acidity of the mine waters was neutralized by microbial sulfidogenesis. Metals present in the MIWs were precipitated either off-line or in-line, inside the reactor vessel. High sulfate reduction rates (SRRs), from 1000 to 4500 mg L-1 d-1 at a temperature of 11.7 ± 0.2 °C, were achieved (sulfate removal 43–87%). The bacterial consortium was found to be robust and resistant to changes in growth conditions during the bioreactor experiment. The relative abundance of SRB and the SRR increased at higher sulfate concentrations. Sulfidogenic bioreactors have the potential for treatment of acid mine drainage even at low temperature. It was demonstrated that neutral reactor conditions and high SRRs were maintained when acidic influent was fed into the reactor. [ABSTRACT FROM AUTHOR]

[Display omitted] • State-of-the-art MOFs-based materials in SR-AOPs for environmental remediation are overviewed. • The synthetic strategies of multifarious MOFs-based materials are summarized. • The effects of structure on the catalytic activities and the circumstance of radical and non-radical pathways are discussed. • DFT for the exploration of possible mechanisms in MOFs-based SR-AOPs are exhibited. • Prospects are highlighted for future research in the field of MOFs-based SR-AOPs. Recently, metal–organic frameworks (MOFs) based materials as the emerging catalysts for sulfate radical-based advanced oxidation processes (SR-AOPs) applications have progressively become a burgeoning research field. Herein, an in-depth overview of state-of-the-art MOFs-based materials currently available in SR-AOPs applications for environmental remediation is presented. The synthetic strategies of different types of MOFs-based materials are summarized. Most importantly, particular emphasis is placed on the applications of MOFs-based materials in SR-AOPs for wastewater treatment. Identification of reactive oxygen species (ROS) generated from the radical and non-radical pathways is addressed. Moreover, the theoretical calculations based on density functional theory (DFT) to predict and explore the possible reaction mechanisms in MOFs-based SR-AOPs are summarized and discussed. Special attention has been focused on the effects of structure on the catalytic activities and the circumstance of radical and non-radical reaction mechanisms in MOFs-based SR-AOPs. Finally, the unresolved challenges of the existent MOFs-based SR-AOPs are pointed out and the outlooks of future research directions are proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • State-of-the-art MOFs-based materials in SR-AOPs for environmental remediation are overviewed. • The synthetic strategies of multifarious MOFs-based materials are summarized. • The effects of structure on the catalytic activities and the circumstance of radical and non-radical pathways are discussed. • DFT for the exploration of possible mechanisms in MOFs-based SR-AOPs are exhibited. • Prospects are highlighted for future research in the field of MOFs-based SR-AOPs. Recently, metal–organic frameworks (MOFs) based materials as the emerging catalysts for sulfate radical-based advanced oxidation processes (SR-AOPs) applications have progressively become a burgeoning research field. Herein, an in-depth overview of state-of-the-art MOFs-based materials currently available in SR-AOPs applications for environmental remediation is presented. The synthetic strategies of different types of MOFs-based materials are summarized. Most importantly, particular emphasis is placed on the applications of MOFs-based materials in SR-AOPs for wastewater treatment. Identification of reactive oxygen species (ROS) generated from the radical and non-radical pathways is addressed. Moreover, the theoretical calculations based on density functional theory (DFT) to predict and explore the possible reaction mechanisms in MOFs-based SR-AOPs are summarized and discussed. Special attention has been focused on the effects of structure on the catalytic activities and the circumstance of radical and non-radical reaction mechanisms in MOFs-based SR-AOPs. Finally, the unresolved challenges of the existent MOFs-based SR-AOPs are pointed out and the outlooks of future research directions are proposed. [ABSTRACT FROM AUTHOR]