Removal Of Emerging Contaminants Research Articles

Coupling machine learning and theoretical models to compare key properties of biochar in adsorption kinetics rate and maximum adsorption capacity for emerging contaminants

Insights into key properties of biochar with a fast adsorption rate and high adsorption capacity are urgent to design biochar as an adsorbent in pollution emergency treatment. Machine learning (ML) incorporating classical theoretical adsorption models was applied to build prediction models for adsorption kinetics rate (i.e., K) and maximum adsorption capacity (i.e., Qm) of emerging contaminants (ECs) on biochar. Results demonstrated that the prediction performance of adaptive boosting algorithm significantly improved after data preprocessing (i.e., log-transformation) in the small unbalanced datasets with R2 of 0.865 and 0.874 for K and Qm, respectively. The surface chemistry, primarily led by ash content of biochar significantly influenced the K, while surface porous structure of biochar showed a dominant role in predicting Qm. An interactive platform was deployed for relevant scientists to predict K and Qm of new biochar for ECs. The research provided practical references for future engineered biochar design for ECs removal.

Removal and risk assessment of emerging contaminants and heavy metals in a wastewater reuse process producing drinkable water for human consumption

This study focuses on the removal and risk assessment of twenty emerging contaminants (ECs) and heavy metals in a REMIX water treatment plant (RWTP) that produces drinking water from combination of wastewater reuse and desalination. The membrane biological reactor (MBR) exhibit removal rates exceeding 95% of pharmaceuticals like acetaminophen, trimethoprim, diclofenac, naproxen, and emtricitabine. The efficiency of brackish reverse osmosis (BWRO) in removing ECs is highlighted, showing substantial efficacy with reduction rates of 99.5%, 75.5%, and 51.2% for sulfamethoxazole, venlafaxine, and benzotriazole, respectively. The advanced oxidation process based on Fenton process reveals removal (>95%) of emtricitabine, efavirenz, and carbamazepine. The study confirms that the combination of treatment units within the RWTP effectively removes heavy metals (>90%), complying with acceptable limits. Risk quotient (RQ) calculations indicate the efficiency of the RWTP in EC removal, serving as benchmarks for public acceptance of reclaimed water. In the context of heavy metals, the study concludes negligible cancer risks associated with reclaimed water consumption over a lifetime. Quantitative structure-activity relationship and occurrence, persistence, bioaccumulation and toxicity (OPBT) models were used to assess EC risk. The study screened and identified potential persistant, bio accumulating and toxic PBT ECs. Critical control points (CCPs) in the RWTP are identified, with brackish and seawater reverse osmosis (BWRO and SWRO) and advanced oxidation process (AOP) recognized as pivotal in hazard management. The study provides valuable insights on the removal of ECs and heavy metals in a wastewater reuse process and demonstrates potential of adopted process configuration in supplying safe drinking water from wastewater recycling.

Insights into the effect of nitrate photolysis on short-chain fatty acids production from waste activated sludge in anaerobic fermentation system: Performance and mechanisms

Nitrate photolysis has become an efficient, low-cost and promising technology for emerging contaminants removal, while its performance and mechanism for waste activated sludge (WAS) treatment is still unknown. This study innovatively introduced nitrate photolysis for WAS disintegration, and investigated the effect of nitrate addition (150-375 mg N/L) for short-chain fatty acids (SCFAs) production during anaerobic fermentation (AF). The results showed that nitrate photolysis significantly promoted the SCFAs production from WAS, and peaked at 280.7 mg/g VSS with 7-d fermentation with 150 mg N/L addition (150N-UV), which increased by 8.8-35.0% and 10.7-23.3% compared with other photolysis groups and sole nitrate groups. Effective release of the soluble organics was observed in the nitrate photolysis groups during AF, especially soluble proteins, reaching 1505.4 mg COD/L at 9 d in 150N-UV group, promoted by 7.0∼15.7% than nitrate/nitrate photolysis groups. The model compounds simulation experiment further demonstrated the positive effect of nitrate photolysis on organics hydrolysis and SCFAs accumulation. The result of the radical capture and quenching verified the reactive oxygen species contributed more compared with reactive nitrogen species. Functional group analysis confirmed the effective bioconversion of the macromolecular organics during the fermentation. Moreover, the nitrate photolysis enhanced the enrichment of the functional consortia, including anaerobic fermentation bacteria (AFB), e.g., Fnoticella, Romboutsia, Gracilibacter and Sedimentibacter, and nitrate reducing bacteria (NRB), e.g., Acinerobacter and Ahniella. The macrogenetic analysis further revealed that glycolysis, amino acid metabolism, acetate metabolism and nitrogen metabolism were the dominating metabolic pathways during fermentation, and the abundance of the relevant genes were enhanced in 150N-UV group.

Algal Membrane Bioreactors for Efficient Removal of Emerging Contaminants and Resource Recovery: Current Advances and Future Outlook

Emerging contaminants (ECs), whether of synthetic or natural origin, pose a significant environmental concern, particularly in the context of industrial wastewater. The Algae Membrane Photobioreactor (AMBR) has emerged as a promising technology for ECs remediation. AMBRs effectively remove contaminants due to its considerable flexibility, scalability and a huge surface area for pollutant adsorption. The productivity and efficiency of biomass are increased when it operates in regulated conditions, which minimizes land footprint. AMBR hold immense appeal in favoring integrated circular economy approach and its implementation could achieve the goals for carbon-neutrality and resource recovery by producing value-added products like biofuels, bioplastics, biochemicals, animal feed, biofertilizers and waste re-uses. However, addressing scalability, harvesting efficiency, membrane fouling, algal strain optimization, economic viability, and regulatory approval are some of the challenges faced in order to the advancement of AMBR technology. Life cycle assessments (LCA) and techno-economic assessments (TEAs) are crucial area of future research in implementation of AMBR at pilot scale. LCA evaluates the sustainability of AMBRs with those of conventional techniques. In contrast, TEA examines economic viability parameters like cost-effectiveness, by-product market potential, and policy implications for AMBR implementation. This review emphasizes AMBR's advantages over conventional wastewater treatment technologies in detail, focusing on algal physiology responsible for ECs removal. The innovations related to the design and configuration of AMBRs are also discussed. Several benefits of this technology via integrated circular paradigm are highlighted. Noteworthy pilot case studies, LCA, TEA, challenges and future perspective are spotlighted to underscore the compelling promise of this technology.

Immobilizing cobalt-iron bimetal on Al2O3 by electroless plating-calcination for peroxymonosulfate activation: Performance, mechanistic and practicality

Peroxymonosulfate (PMS) based advanced oxidation processes are promising technologies for emerging contaminants removal and exploring catalysts with high catalytic activity and low metal leaching for PMS activation gets a lot of attention. Herein, Co-Fe/Al2O3 was synthesized by electroless plating-calcination method. Characterizations indicated that Co and Fe were uniformly dispersed on the surface of Al2O3. Results demonstrated that Co-Fe/Al2O3-PMS system could achieve 100 % sulfamethoxazole (SMX) removal with kobs of 0.0552 min−1 under optimal conditions of [PMS] = 0.20 mM, [Co-Fe/Al2O3] = 50.0 mg/L, pH = 6.4. Compared with Co/Al2O3-PMS, Fe/Al2O3-PMS, Co-Fe/Al2O3 alone, and PMS alone, the developed Co-Fe/Al2O3-PMS system achieved a combination of high decontamination efficiency, efficient PMS utilization and insignificant Co leaching. The electrochemistry tests proved the electron transfer speed of Co-Fe/Al2O3 is much higher than that of Co/Al2O3 and Fe/Al2O3, suggesting the synergistic effect of Co and Fe to enhance catalytic activity. The catalytic mechanisms were proposed that both CoII and FeII could react with PMS to initiate activation with SO4•- formation as the major active species and the coexistence of Fe and Co on Al2O3 promoted the heterogeneous redox cycle of CoII/CoIII with CoII involving in PMS activation again. Furthermore, Cl− and H2PO4- facilitated SMX removal, while HCO3− and HA inhibited SMX removal. Co-Fe/Al2O3-PMS system could retain more than 80 % SMX removal within five cycles, indicating good stability and reusability of Co-Fe/Al2O3 for PMS activation. Aniline ring oxidation and isoxazole ring oxidation were proposed as dominant degradation pathways according to the detected intermediates of SMX degradation. This research was instructive to the development of PMS activation induced by supported bimetallic catalysts for wastewater treatment.

Evaluating an integrated nano zero-valent iron column system for emerging contaminants removal from different wastewater matrices – Identification of transformation products

The presence of micropollutants in water bodies has become a growing concern due to their persistence, bioaccumulation and potential toxicological effects on aquatic life and humans. In this study, the performance of a column system consisting of zero-valent iron nanoparticles (nZVI) incorporated into a cationic resin and synthesized from green tea extract with the addition of persulfate for the elimination of selected pharmaceuticals and endocrine disruptors from wastewater is evaluated. Ibuprofen, naproxen, diclofenac and ketoprofen were the target pharmaceuticals from non-steroidal anti-inflammatory drugs group, while bisphenol A was the target endocrine disruptor. In this context, different real wastewater effluent matrices were investigated: anaerobic membrane bioreactor (AnMBR), upflow anaerobic sludge blanket reactor (UASB) after microfiltration, tertiary treated by conventional activated sludge system and saturated vertical constructed wetland followed by a sand filtration unit effluent (hybrid). The transformation products of diclofenac and bisphenol A were also identified. The experimental results indicated that the performance of the R-nFe/PS system towards the removal efficiency of the target compounds was enhanced in the order of effluents: tertiary > AnMBR ≈ hybrid > UASB. More than 70% removal was obtained for almost all target compounds when conventional tertiary effluent was used, while the maximum removal efficiency was about 50% in the case of filtered UASB. As far as we know, this is the first time that nZVI has been assessed in combination with persulfate for the removal of micropollutants in a continuous flow system receiving various types of real wastewater with different matrix characteristics.

Fast elimination of emerging contaminates in complicated water environment medium over the resource conversion product of chicken manure biochar triggered by peroxymonosulfate

An innovative strategy for synthesizing novel dual-reaction-center (DRC) catalysts from chicken manure (CM) biochar to purify wastewater that contained emerging contaminants (ECs) is proposed to synchronously address the release of ECs and improper disposal of livestock manure. A series of characterization techniques reveal the formation of a special C-O-Ca bond bridge (cation-π) structure on resourcelized CM nanosheets (RCM NSs). RCM NSs exhibit distinct selectivity and anti-interference capability for various ECs removal in complex matrices, and the water purification system remains stable after 1735 hours (equivalent to 3470 cycles) of operation. Density Functional Tomography (DFT) calculations reveal that trace of peroxymonosulfate as an inducer initiates the continuous donation of electrons from electron-rich ECs and the C-O-Ca bond bridges provide a favorable pathway for electron transfer, which facilitates the electron capture effect of dissolved oxygen in the system. This study provides a novel strategy to convert livestock manure into DRC-catalysts for developing energy-saving and high-efficiency environmental remediation technologies.Graphical

Microalgae: A potential bioagent for treatment of emerging contaminants from domestic wastewater

Water crisis around the world leads to a growing interest in emerging contaminants (ECs) that can affect human health and the environment. Research showed that thousands of compounds from domestic consumers, such as endocrine disrupting chemicals (EDCs), personal care products (PCPs), and pharmaceuticals active compounds (PhAcs), could be found in wastewater in concentration mostly from ng L−1 to μg L−1. However, generally, wastewater treatment plants (WWTPs) are not designed to remove these ECs from wastewater to their discharge levels. Scientists are looking for economically feasible biotreatment options enabling the complete removal of ECs before discharge. Microalgae cultivation in domestic wastewater is likely a feasible approach for removing emerging contaminants and simultaneously removing any residual organic nutrients. Microalgal growth rate and contaminants removal efficiency could be affected by various factors, including light intensity, CO2 addition, presence of different nutrients, etc., and these parameters could greatly help make microalgae treatment more efficient. Furthermore, the algal biomass harvests could be repurposed to produce various bulk chemicals such as sustainable aviation fuel, biofuel, bioplastic, and biochar; this could significantly enhance the economic viability. Therefore, this review summarizes the microalgae-based bioprocess and their mechanisms for removing different ECs from different wastewaters and highlights the different strategies to improve the ECs removal efficiency. Furthermore, this review shows the role of different ECs in biomass profile and the relevance of using ECs-treated microalgae biomass to produce green products, as well as highlights the challenges and future research recommendations.

A sustainable and highly efficient fossil-free carbon from olive stones for emerging contaminants removal from different water matrices

The olive stone is a large waste product of the olive oil extraction industry. The present study investigates developing activated carbon from olive stone waste (OSAC) to remove pharmaceuticals from water. Different temperatures and olive stone: KOH ratios were studied. The OSAC produced at 750 °C and 1:3 ratio was found to have the highest porosity and surface area and was tested in the adsorption process. Diclofenac and ciprofloxacin were selected as model contaminants. The adsorption process was optimized with regards to OSAC dosage, pH, temperature, and initial concentration of adsorbate. The OSAC was found to be effective for a wide pH range (2–11) with an optimum dosage of 1 g/L at 25 °C. The pharmaceuticals were almost completely removed in 75 min. The adsorption was endothermic and followed first-order kinetics with physical mechanisms such as electrostatic possibly being the main driver. The optimum conditions were applied to test the removal of diclofenac and ciprofloxacin in synthetic water, lake water (Lake Balaton, Hungary) and secondary wastewater for seven cycles. There was little difference between the removal of the tested water matrices highlighting the potency of OSAC as an adsorbent for pharmaceutical removal in industrial applications. The removal dropped from >99% for the first cycle to 20–30% for the seventh cycle.

Targeted multi-analyte UHPLC-MS/MS methodology for emerging contaminants in septic tank wastewater, sludge and receiving surface water.

Septic tanks treat wastewater of individual houses and small communities (up to 2000 people in Scotland) in rural and semi-urban areas and are understudied sources of surface water contamination. A multi-analyte methodology with solid phase extraction (SPE), ultra-sonic extraction, and direct injection sample preparation methods was developed to analyse a comprehensive range of emerging contaminants (ECs) including prescription and over-the-counter pharmaceuticals and related metabolites, natural and synthetic hormones, and other human wastewater marker compounds in septic tank influent and effluent, river water, suspended solids, and septic tank sludge by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The number of quantifiable compounds in each matrix varied from 68 in septic tank wastewater to 59 in sludge illustrating its applicability across a range of matrices. Method quantification limits were 2.9 × 10-5-1.2 μg L-1 in septic tank influent, effluent and river water, with ≤0.01 μg L-1 achieved for 60% of ECs in all three water matrices, and 0.080-49 μg kg-1 in sludge. The developed method was applied to a septic tank (292 population equivalents) and the receiving river in the North-East of Scotland. Across all samples analysed, 43 of 68 ECs were detected in at least one matrix, demonstrating the method's sensitivity. The effluent concentrations suggest limited removal of ECs in septic tanks and a potential impact to river water quality for some ECs. However, further monitoring is required to better appreciate this. The developed methodology for a wide variety of ECs in a range of liquid and solid phases will allow, for the first time, a comprehensive assessment of ECs fate and removal in septic tanks, and their impact to surface water quality.

Enhanced Fenton-like process over Cu/L(+)-ascorbic acid co-doping mesoporous silica for toxicity reduction of emerging contaminants

Effective removal of emerging contaminants (ECs) to minimize their impacts on human health and the natural environment is a global priority. For the removal of ECs in water, we fabricated a seaweed spherical microsphere catalyst with Cu cation-π structures by in situ doping of Cu species and ascorbic acid in mesoporous silica (Cu-C-MSNs) via a hydrothermal method. The results indicate that bisphenol A (BPA) is substantially degraded within 5 min under natural conditions, with its biological toxicity considerably weakened. Moreover, industrial wastewater could also be effectively purified by Cu-C-MSNs/H2O2 system. The presence of metal sites and the complexation of ECs via cation-π interaction and π-π stacking on the catalyst surface were directly responsible for the polarization distribution of electrons, thus activating H2O2 and dissolved oxygen (DO). The removal of contaminants could be attributed primarily to 1) the activation of H2O2 into •OH to attack the contaminants and 2) self-cleavage because of the transfer of electrons from the contaminants to the catalysts. This study provides an innovative solution for the effective treatment of ECs and has positive implications for easing global environmental crises.

Selective formation of high-valent iron in Fenton-like system for emerging contaminants degradation under near-neutral and high-salt conditions

In view of the near-neutral and high-salt conditions, the Fenton technology with hydroxyl radicals (HO•) as the main reactive species is difficult to satisfy the removal of trace emerging contaminants (ECs) in pharmaceutical sewage. Here, a layered double hydroxide FeZn-LDH was prepared, and the selective formation of ≡Fe(IV)=O in Fenton-like system was accomplished by the chemical environment regulation of the iron sites and the pH control of the microregion. The introduced zinc can increase the length of Fe-O bond in the FeZn-LDH shell layer by 0.22 Å compared to that in Fe2O3, which was conducive to the oxygen transfer process between ≡Fe(III) and H2O2, resulting in the ≡Fe(IV)=O formation. Besides, the amphoteric hydroxide Zn(OH)2 can regulate the pH of the FeZn-LDH surface microregion, maintaining reaction pH at around 6.5–7.5, which could avoid the quenching of ≡Fe(IV)=O by H+. On the other hand, owing to the anti-interference of ≡Fe(IV)=O and the near-zero Zeta potential on the FeZn-LDH surface, the trace ECs can also be effectively degraded under high-salt conditions. Consequently, the process of ≡Fe(IV)=O generation in FeZn-LDH system can satisfy the efficient removal of ECs under near-neutral and high-salt conditions.

A review on constructed wetlands for environmental and emerging contaminants removal from wastewater: traditional and recent developments

A review on constructed wetlands for environmental and emerging contaminants removal from wastewater: traditional and recent developments

Emerging Contaminants Removal from Wastewater Using Organo-Modified Bentonite Clay

Organo-modified bentonite clay locally sourced from Bauchi State, Nigeria was prepared and used as an adsorbent for Emerging Contaminants (EC) capture from Kaduna Polytechnic female hostel wastewater. The produced adsorbent was characterized to determine the functional groups, surface area and crystal structure. Surface area for directly modified bentonite clay produced adsorbents and oxalic acid-pretreated bentonite clay adsorbent was found to be 625 m2/g and 349.2 m2/g respectively and the morphology of the produced acid-pretreated organo-modified bentonite clay adsorbents has better pore development with a higher amorphous structure. The wastewater compositions were found to contain major ECs identified to be Diclofenac, Triclosan, Methylparaben, and Bisphenol A, which account for 76.206% of the ECs that are detrimental to human and the environment. The impact of the adsorption factors; contact time, adsorbent dosage, and temperature on uptake behavior were all examined. Effect of adsorbent dosage was established which shows that all ECs removed rise rapidly from 0.5 – 1.0 g adsorbent dosage and then slowly reach a maximum of 98.65% Triclosan, 95.83% Diclofenac, 91.49% BPA, and 62.16% Methyl-Paraben removal as adsorbent dosage increases to 2g. On the other hand, as the adsorbent dosage increases to 3g, the removal rate of all ECs was observed to drop slightly and then attain maximum removal as the dosage rises to 4g. In contrast, a rise in adsorbent dosage of 2.5g gives a sudden drop in removal of Triclosane to 92.41% and Methyl-Paraben to 53.01% as well as a sharp drop in Methyl-Paraben to 33.33% and slightly drop in the removal of all other ECs. Langmuir and Freundlich isotherms models were fitted to the adsorption data and Freundlich showed best fit indicating chemisorption. The adsorption of triclosan, diclofenac, bisphenol A, and methylparaben followed pseudo second-order kinetic model.

Sulfur vacancies-induced electron delocalization effect of cobalt sulfide for enhanced catalytic activation of peracetic acid and norfloxacin degradation

Antibiotics have attracted widespread attention due to their potential risks to human health and environment. In this study, a heterogeneous advanced oxidation process (AOP) of peracetic acid (PAA) activation by cobalt material was developed to degrade a typical antibiotic, norfloxacin (NOR). Cobalt sulfide materials with sulfur vacancies (CoSx) were synthesized through a two-step hydrothermal process. The optimized material (CoSx-2) could efficiently activate PAA system, achieving 91.8% NOR degradation in 5 min. The Co(II)/Co(III) species in CoSx was key to activating PAA, as Co(II) initiated the reaction and Co(III) activation caused the production of CH3C(=O)OO• species. Moreover, the presence of sulfur vacancies (VS) led to the generation of hydroxyl radicals (•OH) and singlet oxygen (1O2) via chain reactions with CH3C(=O)OO•. Density functional theory (DFT) calculations reveal the contribution of VS to enhanced catalytic PAA activation, as the lower work function (5.76 eV), higher adsorption energy (-3.43 eV), bridge effect of delocalized electrons and shifted d-band center are achieved to reduce the energy barrier for electron transfer during catalytic reaction. In addition, DFT calculation on Fukui index further explains that 18 N and 21 N are reactive sites of NOR for electrophilic attack, leading to primary degradation pathways of C–N cleavage, defluorination, dealkylation and hydroxylation. This study gives a new perspective on the regulation of material structure for efficient activation of PAA and promotes the practical application of heterogenous PAA-based AOPs for emerging contaminants removal in water treatment process.

Occurrence, removal, and risk assessment of emerging contaminants in aquatic products processing sewage treatment plants.

Emerging contaminants (ECs) in aquatic environments have attracted attention due to their wide distribution and potential ecotoxicities. Sewage treatment plants (STPs) are proven to be the major source of ECs in the aquatic environment, while there remains insufficient understanding of the removal and risk assessment of ECs in STPs. Here, we clarified the degradation and risk impact of 13 ECs in two aquatic product processing sewage treatment plants (APPSTPs) along the southeast coast of China. The concentrations of ECs followed the order: endocrine-disrupting chemicals (1877.85-15,398.02ng/L in influent, 3.37-44.47ng/L in effluent) > > sulfonamide antibiotics (SAs, 75.14-906.19ng/L in influent, 1.14-15.33ng/L in effluent) > pharmaceutical and personal care products (PPCPs, 44.47-589.93ng/L in influent, 2.54-34.16ng/L in effluent) ≈ fluoroquinolone antibiotic (54.76-434.83ng/L in influent, 10.75-32.82ng/L in effluent) > other antibiotics (16.21-51.96ng/L in influent, 0.68-6.17ng/L in effluent). Moreover, the concentrations of PPCPs (decreased by 55.33-87.65% in peak fishing season) and antibiotics (increased by 44.99% in peak fishing season) were affected by fishing activities. In particular, the sequencing batch reactor (SBR) process had a better removal effect than the anaerobic-anoxic-oxic (A2/O) process on the treatment of some contaminants (e.g., norfloxacin and nonylphenol). Risk evaluations of ECs demonstrated that nonylphenol and SAs were at high- and low-risk states, respectively. Overall, our results provide important information for the degradation treatment of ECs, which is essential for pollutant management policy formulation.

Advanced steam-explosion pretreatment mediated anaerobic digestion of municipal sludge: Effects on methane yield, emerging contaminants removal, and microbial community

Advanced steam explosion pretreatment, i.e., the Thermal hydrolysis process (THP) is applied mainly to improve the sludge solubilization and subsequent methane yield in the downstream anaerobic digestion (AD) process. However, the potential of THP in pretreating the high solids retention time (SRT) sludges, mitigating the risk of emerging organic micropollutants and effects on anaerobic microbiome in digester remains unclear. In this study, sludge from a sequencing batch reactor (SBR) system operating at a SRT of 40 days was subjected to THP using a 5 L pilot plant at the temperature ranges of 120–180 °C for 30–120 min. The effect of THP on organics solubilization, methane yield, organic micropollutant removal, and microbial community dynamics was studied. The highest methane yield of 507 mL CH4/g VSadded and volatile solids (VS) removal of 54% were observed at 160°C- 30min THP condition, i.e., 4.1 and 2.6 times higher than the control (123 mL CH4/gVSadded, 20.7%), respectively. The experimental values of hydrolysis coefficient and methane yield have been predicted using Modified Gompertz, First order, and Logistics models. The observed values fitted well with all three models showing an R2 value between 0.96 and 1.0. THP pretreated sludges showed >80% removal of Trimethoprim, Enrofloxacin, Ciprofloxacin, and Bezafibrate. However, Carbamazepine, 17α-ethinylestradiol, and Progesterone showed recalcitrant behavior, resulting in less than 50% removal. Microbial diversity analysis showed the dominance of Proteobacteria, Firmicutes, Chloroflexi, and Bacteroidetes, collectively accounting for >70–80% of bacterial reads. They are mainly responsible for the fermentation of complex biomolecules like polysaccharides, proteins, and lipids. The THP-mediated anaerobic digestion of sludge shows better performance than the control digestion, improved methane yield, higher VS and micropollutants removal, and a diverse microbiome in the digester.

Surface modify BiOBr/Mn-Ti3C2Tx to enhance the carrier separation efficiency and weak electron utilization for photo-assisted peroxymonosulfate activation to degrade emerging contaminants

The low separation efficiency and light utilization of photogenerated carriers are one of the key problems in photocatalysis. This, Mn-Ti3C2Tx was prepared by surface modification of Ti3C2Tx, BiOBr/Mn-Ti3C2Tx composite photocatalysts were synthesized through in situ ion modification. The synergy of surface modification and built-in electric field improves carrier separation efficiency and weak electron utilization. This can promote electrocatalytic reduction of peroxymonosulfate (PMS) to produce SO4·- and improve electron utilization. The various photovoltaic properties characterization found that BiOBr/Mn-Ti3C2Tx exhibited superior light capture ability and carrier separation efficiency compared to BiOBr/Ti3C2Tx, and thus had more efficient photocatalytic degradation performance, which was found to be increased from 90.88% to 98.29% using emerging contaminants as the target pollutant. Secondly, the migration path of carriers in BiOBr/Mn-Ti3C2Tx was analyzed by In Situ Irradiated X-Ray Photoelectron Spectroscopy (ISI-XPS) as well as the proposed mechanism of ciprofloxacin (CIP) degradation by BiOBr/Mn-Ti3C2Tx photo-assisted activation of PMS. The possible pathways of CIP degradation were further explored by liquid chromatograph mass spectrometer (LC-MS), revealing that the BiOBr/Mn-Ti3C2Tx photocatalytic degradation pathways. In this work, a strategy of surface modification and built-in electric field synergy is proposed to improve the photogenerated carrier separation and light utilization efficiency for enhancing the emerging contaminants removal.

Pharmaceutical-Based Emerging Contaminants Removal from Aqueous Solution by Different Granular Activated Carbon-Based Adsorbents

Pharmaceutical-Based Emerging Contaminants Removal from Aqueous Solution by Different Granular Activated Carbon-Based Adsorbents

New insights into degradation of emerging contaminants by S(IV)/Fe(VI) system in neutral water: Performance enhancement, reaction mechanisms and toxicity assessment

This study proposes a novel approach to enhance the degradation of emerging contaminants (ECs) in neutral water using the S(IV)/Fe(VI) system and identifies the significant role of high-valent iron (Fe(V)/Fe(IV)) in selective oxidation. In the complex of bisulfite and sulfite (B1S3)/Fe(VI) system, the degradation rates and pseudo-first-order rate constants of sulfamethoxazole (SMX), carbamazepine (CBZ), 2,4-dihydroxybenzophenone (BP-1) and 4,4′-sulfonyldiphenol (BPS) were higher than those achieved with single S(IV) activation Fe(VI). The results were attributed to the dominance of Fe(V)/Fe(IV) in the selective oxidations which involved the participation of HO• and SO4•−. In addition, the degradation mechanisms of SMX, CBZ, BP-1, and BPS were proposed, and the acute toxicity, chronic toxicity, developmental toxicity, and bioaccumulation factors of the transformation products were assessed. The results showed that the removal of ECs by the B1S3/Fe(VI) system resulted in a reduction in toxicity. The effects of experimental conditions and water matrix on the removal of ECs were evaluated and achieved satisfactory results in three different real water samples. The B1S3/Fe(VI) system was capable of rapid degradation of ECs at relatively low S(IV) and Fe(VI) doses, and the ultimate products (SO42− and Fe(III)) promoted coagulation, indicating multiple application scenarios and tremendous engineering potential.