The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,wh...The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,while comorbidities(e.g.,hypertension and diabetes)and mental shock(e.g.,insomnia and anxiety)are nonnegligible.Nevertheless,little is known about the long-term impacts of comorbidities and mental shock on organic micropollutants(OMPs)in surface waters.Herein,we monitored 114 OMPs in surface water and wastewater treatment plants(WWTPs)in Wuhan,China,between 2019 and 2021.The pandemic-induced OMP pollution in surface water was confirmed by significant increases in 26 OMP concentrations.Significant increases in four antihypertensives and one diabetic drug suggest that the treatment of comorbidities may induce OMP pollution.Notably,cotinine(a metabolite of nicotine)increased 155 times to 187 ngL1,which might be associated with increased smoking.Additionally,the increases in zolpidem and sulpiride might be the result of worsened insomnia and depression.Hence,it is reasonable to note that mental-health protecting drugs/behavior also contributed to OMP pollution.Among the observed OMPs,telmisartan,lopinavir,and ritonavir were associated with significantly higher ecological risks because of their limited WWTP-removal rate and high ecotoxicity.This study provides new insights into the effects of comorbidities and mental shock on OMPs in surface water during a pandemic and highlights the need to monitor the fate of related pharmaceuticals in the aquatic environment and to improve their removal efficiencies in WWTPs。展开更多
The degradation of micropollutants in water via ultraviolet(UV)-based advanced oxidation processes(AOPs)is strongly dependent on the water matrix.Various reactive radicals(RRs)formed in UV-AOPs have different reaction...The degradation of micropollutants in water via ultraviolet(UV)-based advanced oxidation processes(AOPs)is strongly dependent on the water matrix.Various reactive radicals(RRs)formed in UV-AOPs have different reaction selectivities toward water matrices and degradation efficiencies for target micropollutants.Hence,process selection and optimization are crucial.This study developed a facilitated prediction method for the photon fluence-based rate constant for micropollutant degradation(K′_(p,MP))in various UV-AOPs by combining model simulation with portable measurement.Portable methods for measuring the scavenging capacities of the principal RRs(RRSCs)involved in UV-AOPs(i.e.,HO^(·),SO_(4)^(·-),and Cl^(·))using a mini-fluidic photoreaction system were proposed.The simulation models consisted of photochemical,quantitative structure–activity relationship,and radical concentration steady-state approximation models.The RRSCs were determined in eight test waters,and a higher RRSC was found to be associated with a more complex water matrix.Then,by taking sulfamethazine,caffeine,and carbamazepine as model micropollutants,the k′_(p,MP) values in various UV-AOPs were predicted and further verified experimentally.A lower k′_(p,MP) was found to be associated with a higher RRSC for a stronger RR competition;for example,k′_(p,MP) values of 130.9 and 332.5 m^(2) einstein^(–1),respectively,were obtained for carbamazepine degradation by UV/H_(2)O_(2) in the raw water(RRSC=9.47×10^(4) s^(-1))and sand-filtered effluent(RRSC=2.87×10^(4) s^(-1))of a drinking water treatment plant.The developed method facilitates process selection and optimization for UV-AOPs,which is essential for increasing the efficiency and cost-effectiveness of water treatment.展开更多
The removal of emerging micropollutants in the aquatic environment remains a global challenge.Conventional routes are often chemically,energetically,and operationally intensive,which decreases their sustainability dur...The removal of emerging micropollutants in the aquatic environment remains a global challenge.Conventional routes are often chemically,energetically,and operationally intensive,which decreases their sustainability during applications.Herein,we develop an advanced chemical-free strategy for micropollutants decontamination that is solely based on sequential electrochemistry involving ubiquitous sulfate anions in natural and engineered waters.This can be achieved via a chain reaction initiated by electrocatalytic anodic sulfate(SO_(4)^(2-))oxidation to produce persulfate(S_(2)O_(8)^(2-))and followed by a cathodic persulfate reduction to produce sulfate radicals(SO_(4)^(·-)).These SO_(4)^(·-)are powerful reactive species that enable the unselective degradation of micropollutants and yield SO_(4)^(2-)again in the treated water.The proposed flow-through electrochemical system achieves the efficient degradation(100.0%)and total organic carbon removal(65.0%)of aniline under optimized conditions with a single-pass mode.We also reveal the effectiveness of the proposed system for the degradation of a wide array of emerging micropollutants over a broad pH range and in complex matrices.This work provides the first proof-ofconcept demonstration using ubiquitous sulfate for micropollutants decontamination,making water purification more sustainable and more economical.展开更多
Organic micropollutants,with high toxicity and environmental concern,are present in the landfill leachate at much lower levels than total organic constituents (chemical oxygen demand (COD),biochemical oxygen demand (B...Organic micropollutants,with high toxicity and environmental concern,are present in the landfill leachate at much lower levels than total organic constituents (chemical oxygen demand (COD),biochemical oxygen demand (BOD),or total organic carbon (TOC)),and few has been known for their behaviors in different treatment processes.In this study,occurrence and removal of 17 organochlorine pesticides (OCPs),16 polycyclic aromatic hydrocarbons (PAHs),and technical 4-nonylphenol (4-NP) in landfill leachate in a comb...展开更多
Micropollutants are defined as contaminants found in trace concentrations in water bodies that are persistent and bioactive, meaning they are not completely biodegradable and cannot be removed by conventional water tr...Micropollutants are defined as contaminants found in trace concentrations in water bodies that are persistent and bioactive, meaning they are not completely biodegradable and cannot be removed by conventional water treatment methods. Because of these aspects, their detection and removal pose a challenge to the scientific community. Among them are endocrine disruptors, drugs, agricultural chemicals, personal grooming products, industrial additives and others. These micropollutants are the cause for global concern, because their presence in water supply systems is suspected of causing health problems in humans and animals. To develop efficient techniques to remove them, it is fundamental to understand their physico-chemical properties and the available treatment types and conditions. Membrane separation processes (MSPs) and advanced oxidation processes (AOPs) are the focus of this literature review, as potential treatment methods to remove micropollutants. The former process stands out for high rejection rates (above 90%) of various micropollutants, but it generates a concentrated secondary waste stream. In turn, the latter process can remove micropollutants without generating secondary wastes, and can also be applied and combined with other treatment methods.展开更多
Activated carbon is employed for the adsorption of organic micropollutants(OMPs)from water,typically present in concentrations ranging from ng L1 to mg L1.However,the efficacy of OMP removal is considerably deteriorat...Activated carbon is employed for the adsorption of organic micropollutants(OMPs)from water,typically present in concentrations ranging from ng L1 to mg L1.However,the efficacy of OMP removal is considerably deteriorated due to competitive adsorption from background dissolved organic matter(DOM),present at substantially higher concentrations in mg L1.Interpreting the characteristics of competitive DOM is crucial in predicting OMP adsorption efficiencies across diverse natural waters.Molecular weight(MW),aromaticity,and polarity influence DOM competitiveness.Although the aromaticity-related metrics,such as UV254,of low MW DOM were proposed to correlate with DOM competitiveness,the method suffers from limitations in understanding the interplay of polarity and aromaticity in determining DOM competitiveness.Here,we elucidate the intricate influence of aromaticity and polarity in low MW DOM competition,spanning from a fraction level to a compound level,by employing direct sample injection liquid chromatography coupled with ultrahigh-resolution Fouriertransform ion cyclotron resonance mass spectrometry.Anion exchange resin pre-treatment eliminated 93%of UV254-active DOM,predominantly aromatic and polar DOM,and only minimally alleviated DOM competition.Molecular characterization revealed that nonpolar molecular formulas(constituting 26%PAC-adsorbable DOM)with medium aromaticity contributed more to the DOM competitiveness.Isomerlevel analysis indicated that the competitiveness of highly aromatic LMW DOM compounds was strongly counterbalanced by increased polarity.Strong aromaticity-derived p-p interaction cannot facilitate the competitive adsorption of hydrophilic DOM compounds.Our results underscore the constraints of depending solely on aromaticity-based approaches as the exclusive interpretive measure for DOM competitiveness.In a broader context,this study demonstrates an effect-oriented DOM analysis,elucidating counterbalancing interactions of DOM molecular properties from fraction to compound level.展开更多
Chemistry of the polyamide active layer of a desalination membrane is critical in determining both its physical and chemical properties.In this study,we designed and fabricated three novel membranes with different act...Chemistry of the polyamide active layer of a desalination membrane is critical in determining both its physical and chemical properties.In this study,we designed and fabricated three novel membranes with different active layers using the crosslinkers:terephthaloyl chloride,isophthaloyl chloride,and trimesoyl chloride.The crosslinkers were reacted with an aqueous solution of an aliphatic tetra-amine.Because these crosslinkers differ in their structures and crosslinking mechanisms during interfacial polymerization,the resultant membranes also possess different structural properties.The water contact angle of the fabricated membranes also varies;the water contact angles of 4A-3P-TPC@PSF/PET,4A-3P-TMC@PSF/PET,and 4A-3P-IPC@PSF/PET,are 68.9°,65.6°,and 53.9°,respectively.Similarly,the desalination performance of resultant membranes also showed variations,with 4A-3P-TPC@PSF/PET,4A-3P-IPC@PSF/PET,and 4A-3P-TMC@PSF/PET having a permeate flux of 17.14,25.70,and 30.90 L·m^(−2)·h^(−1),respectively,at 2.5 MPa.The 4A-3P-TPC@PSF/PET membrane exhibited extensive crosslinking with aliphatic linear amine,and cationic dye rhodamine B,MgCl_(2),and amitriptyline rejection rates of 98.6%,92.7%and 80.9%,respectively.The 4A-3P-TMC@PSF/PET membrane showed mediocre performance,while 4A-3P-IPC@PSF/PET membrane showed even lower performance,with a 35%rejection of methyl orange dye.展开更多
Backwashing is crucial for preventing clogging of sand filters.However,few studies have investigated the effect of backwashing on micropollutant removal and the dynamic changes in the microbial community in sand filte...Backwashing is crucial for preventing clogging of sand filters.However,few studies have investigated the effect of backwashing on micropollutant removal and the dynamic changes in the microbial community in sand filters.Here,we used a series of manganese and quartz sand filters under empty bed contact times(EBCTs)of 2 h and 4 h to explore variations in micropollutant degradation and temporal dynamics of the microbial community after backwashing.The results showed that the removal efficiencies of caffeine,sulfamethoxazole,sulfadiazine,trimethoprim,atrazine,and active biomass recovered within 2 d after backwashing in both types of sand filters at 2-h EBCT,but the recovery of sulfadiazine and trimethoprim was not observed at 4-h EBCT.Moreover,the removal efficiency of atenolol increased after backwashing in the manganese sand filters,whereas maintained almost complete removal efficiency in the quartz sand filters at both EBCTs.Pearson correlation analysis indicated that microbial community composition gradually recovered to the pre-backwashing level(R increased from 0.53 to 0.97)at 2-h EBCT,but shifted at 4-h EBCT(R<0.25)after backwashing.Furthermore,the compositions of the recovered,depleted,and improved groups of microbes were distinguished by applying hierarchical clustering to the differentially abundant amplicon sequence variants.The cumulative relative abundance of recovered microbes at 2-h EBCT was 82.76%±0.43%and 46.82%±4.34%in the manganese and quartz sand filters,respectively.In contrast,at 4-h EBCT,the recovered microbes dropped to 15.55%–25.69%in both types of sand filters.展开更多
To perform a systematic survey on the occurrence and removal of micropollutants during municipal wastewater treatment, 943 semi-volatile organic chemicals in 32 wastewater samples including influents of secondary trea...To perform a systematic survey on the occurrence and removal of micropollutants during municipal wastewater treatment, 943 semi-volatile organic chemicals in 32 wastewater samples including influents of secondary treatments, secondary effluents and final effluents(effluents of advanced treatments), which were collected from seven full-scale municipal wastewater treatment plants(MWTPs) in China, were examined by gas chromatography-mass spectrometry(GC-MS) coupled with an automated identification and quantification system with a database(AIQS-DB). In total, 196 and 145 chemicals were detected in secondary and final effluents, respectively. The majority of the total concentrations(average removal efficiency, 87.0%±5.9%) of the micropollutants were removed during secondary treatments. However, advanced treatments achieved different micropollutant removal extents from secondary effluents depending on the different treatment processes employed. Highly variable removal efficiencies of total concentrations(32.7%–99.3%) were observed among the different advanced processes. Among them,ozonation-based processes could remove 70.0%–80.9% of the total concentrations of studied micropollutants. The potentially harmful micropollutants, based on their detection frequency and concentration in secondary and final effluents, were polycyclic aromatic hydrocarbons(PAHs)(2-methylnaphthalene, fluoranthene, pyrene, naphthalene and phenanthrene), phosphorus flame retardants(tributyl phosphate(TBP), tris(2-chloroethyl)phosphate(TCEP) and tris(1,3-dichloro-2-propyl) phosphate(TDCP)), phthalates(bis(2-ethylhexyl)phthalate(DEHP)), benzothiazoles(benzothiazole,2-(methylthio)-benzothiazol, and 2(3H)-benzothiazolone) and phenol. This study indicated that the presence of considerable amounts of micropollutants in secondary effluent creates the need for suitable advanced treatment before their reuse.展开更多
A rapid and effective method based on a novel permanent magnetic hypercrosslinked resin W150 was proposed for the removal of organic micropollutants in drinking water. W150 was prepared by suspension and post-crosslin...A rapid and effective method based on a novel permanent magnetic hypercrosslinked resin W150 was proposed for the removal of organic micropollutants in drinking water. W150 was prepared by suspension and post-crosslinking reaction and found to possess a high specific surface area of 1149.7 m^2· g^-1, a small particle size of 50 μm to 100 μm, and a saturation magnetization as high as 8 emu.g1. W150 was used to eliminate nitrofurazone (NFZ) and oxytetracycline (OTC) from drinking water compared with commercial adsorbents XAD-4 and F400D. The adsorption kinetics of NFZ and OTC onto the three adsorbents well fitted the pseudo-second-order equation (r 〉 0.972), and the adsorption isotherms were all well described by the Freundlich equation (r 〉 0.851). Results showed that the reduction in adsorbent size and the enlargement in sorbent pores both accelerated adsorption. Moreover, the effect of particle size on adsorption was more significant than that of pore width. Given that the smallest particle size and the highest specific surface area were possessed by W150, it had the fastest adsorption kinetics and largest adsorption capacity for NFZ (180 mg·g-1) and OTC (200mg·g- 1). For the adsorbents with dominant micropores, the sorption of large-sized adsorbates decreased because of the inaccessible micropores. The solution pH and ionic strength also influenced adsorption.展开更多
The performance of water purification by adsorption method has been limited owing to the fact that most of current available adsorbents fail to achieve satisfactory removal performance for organic micropollutants.Here...The performance of water purification by adsorption method has been limited owing to the fact that most of current available adsorbents fail to achieve satisfactory removal performance for organic micropollutants.Herein,we report the design and synthesis of novel porous polymeric adsorbent built fromβ-cyclodextrin(B-CD),in whichβ-CD molecules are arranged in an ordered bis(β-CD)tubular assemblies.The induction of bis(B-CD)units renders them high adsorption affinity toweard bisphenols(bisphenol A and its analogues bisphenol B,bisphenol F and bisphenol S),the typical endocrine disruptors,via the formation of stable host-guest inclusion complexes in aquatic systems.In combination with their high porosity(Brunauer-Emmett-Teller(BET)surface area of 150 m2·g-1),abundantβ-CD content and fast sorption kinetics,the obtained adsorbent outperforms commercial water purifier in elimination of bisphenol micropollutants from potable water.Our work may open a new avenue for designing highly eficient adsorbents for removal of organic micropollutants from aquatic systems.展开更多
Currently,the wastewater treatment plants(WWTPs)attempt to achieve the shifting from general pollution parameters control to reduction of organic micropollutants discharge.However,they have not been able to satisfy th...Currently,the wastewater treatment plants(WWTPs)attempt to achieve the shifting from general pollution parameters control to reduction of organic micropollutants discharge.However,they have not been able to satisfy the increasing ecological safety needs.In this study,the removal of micropollutants was investigated,and the ecological safety was assessed for a local WWTP.Although the total concentration of 31 micropollutants detected was reduced by 83%using the traditional biological treatment processes,the results did not reflect chemicals that had poor removal efficiencies and low concentrations.Of the five categories of micropollutants,herbicides,insecticides,and bactericides were difficult to remove,pharmaceuticals and UV filters were effectively eliminated.The specific photosynthesis inhibition effect and non-specific bioluminescence inhibition effect from wastewater were detected and evaluated using hazardous concentration where 5%of aquatic organisms are affected.The photosynthesis inhibition effect from wastewater in the WWTP was negligible,even the untreated raw wastewater.However,the bioluminescence inhibition effect from wastewater which was defined as the priority biological effect,posed potential ecological risk.To decrease non-specific biological effects,especially of macromolecular dissolved organic matter,overall pollutant reduction strategy is necessary.Meanwhile,the ozonation process was used to further decrease the bioluminescence inhibition effects from the secondary effluent;≥0.34 g O 3/g DOC of ozone dose was recommended for micropollutants elimination control and ecological safety.展开更多
The combination of hologram quantitative structure-activity relationship(HQSAR)and consensus modeling was employed to study the quantitative structure-property relationship(QSPR)model for calculating the aqueous hydro...The combination of hologram quantitative structure-activity relationship(HQSAR)and consensus modeling was employed to study the quantitative structure-property relationship(QSPR)model for calculating the aqueous hydroxyl radical oxidation reaction rate constants(kOH)of organic micropollutants(OMPs).Firstly,individual HQSAR model were established by using standard HQSAR method.The optimal individual HQSAR model was obtained while setting the parameter of fragment distinction and fragment size to“B”and“3~6”respectively.Secondly,consensus HQSAR model was established by building the regression model between the kOH and the hologram descriptors with consensus partial least-squares(cPLS)approach.The obtained individual and consensus HQSAR model were validated with a randomly selected external test set.The result of external test set validation demonstrates that both individual and consensus HQSAR model are available for predicting the kOH of OMPs.Compared with the optimal individual HQSAR model,the established consensus HQSAR model shows higher prediction accuracy and robustness.It is shown that the combination of HQSAR and consensus modeling is a practicable and promising method for studying and predicting the kOH of OMPs.展开更多
The degradation of pharmaceutical micropollutants is an intensifying environmental problem and synthesis of efficient photocatalysts for this purpose is one of the foremost challenges worldwide.Therefore,this study wa...The degradation of pharmaceutical micropollutants is an intensifying environmental problem and synthesis of efficient photocatalysts for this purpose is one of the foremost challenges worldwide.Therefore,this study was conducted to develop novel plasmonic Ag/Ag2O/BiVO4 nanocomposite photocatalysts by simple precipitation and thermal decomposition methods,which could exhibit higher photocatalytic activity for mineralized pharmaceutical micropollutants.Among the different treatments,the best performance was observed for the Ag/Ag2O/BiVO4 nanocomposites (5 wt.%;10 min’s visible light irradiation)which exhibited 6.57 times higher photodegradation rate than the pure BiVO4.Further,the effects of different influencing factors on the photodegradation system of tetracycline hydrochloride (TC-HCl) were investigated and the feasibility for its practical application was explored through the specific light sources,water source and cycle experiments.The mechanistic study demonstrated that the photogenerated holes (h^+),superoxide radicals (·O2^-)and hydroxyl radicals (·OH) participated in TC-HCl removal process,which is different from the pure BiVO4 reaction system.Hence,the present work can provide a new approach for the formation of novel plasmonic photocatalysts with high photoactivity and can act as effective practical application for environmental remediation.展开更多
The ubiquity of micropollutants(MPs)in aquatic environments has attracted increasing concern for public health and ecological security.Compared to conventional biological treatment,photocatalytic processes show more e...The ubiquity of micropollutants(MPs)in aquatic environments has attracted increasing concern for public health and ecological security.Compared to conventional biological treatment,photocatalytic processes show more efficiency in degrading MPs,but they require expensive materials and complicated synthesis processes.This study developed an economic photocatalytic process to degrade micropollutants.We synthesized urea-based graphitic carbon nitride(g-C_(3)N_(4))by a facile one-step pyrolysis method and evaluated the photocatalytic efficiency of carbamazepine(CBZ).Under simulated solar irradiation,g-C_(3)N_(4) could achieve 100% removal efficiency of 0.1 mg/L CBZ in spiked wastewater effluent within 15 min,and 86.5% removal efficiency in wastewater influent after 20 min of irradiation.The porous structure of g-C_(3)N_(4) promoted effective charge separation and mass transport of CBZ near the catalyst surface,enabling a high kinetic rate(0.3662 min^(-1)).Reactive oxygen species trapping experiments revealed that superoxide radicals(O_(2)^(·-))and holes(h^(+))were the major active radicals.Electron paramagnetic resonance(EPR)further confirmed the presence of O_(2)^(·-),·OH,^(1)O_(2) and holes.The pH,light intensity and initial CBZ concentration were found to have significant impacts on the removal efficiency of CBZ.Possible reaction intermediates were identified and the degradation pathway was proposed.Multiple MPs were selected to further demonstrate photocatalytic efficiency of g-C_(3)N_(4).The facile synthesis,superior efficiency,and versatility of g-C_(3)N_(4) make it a promising catalyst for application in tertiary wastewater treatment processes.展开更多
Drinking water utilities are interested in upgrading their treatment facilities to enhance micropollutant removal and byproduct control.Pre-oxidation by chlorine dioxide(ClO_(2))followed by coagulation-flocculation-se...Drinking water utilities are interested in upgrading their treatment facilities to enhance micropollutant removal and byproduct control.Pre-oxidation by chlorine dioxide(ClO_(2))followed by coagulation-flocculation-sedimentation and advanced oxidation processes(AOPs)is one of the promising solutions.However,the chlorite(ClO_(2)^(-))formed from the ClO_(2) preoxidation stage cannot be removed by the conventional coagulation process using aluminum sulfate.ClO_(2)^(–)negatively affects the post-UV/chlorine process due to its strong radical scavenging effect,and it also enhances the formation of chlorate(ClO_(3)^(–)).In this study,dosing micromolar-level ferrous iron(Fe(II))into aluminum-based coagulants was proposed to eliminate the ClO_(2)^(–)generated from ClO_(2) pre-oxidation and benefit the post-UV/chlorine process in radical production and ClO_(3)^(–)reduction.Results showed that the addition of 52.1-μmol/L FeSO_(4) effectively eliminated the ClO_(2)^(-)generated from the pre-oxidation using 1.0 mg/L(14.8μmol/L)of ClO 2.Reduction of ClO_(2)^(-)increased the degradation rate constant of a model micropollutant(carbamazepine)by 55.0%in the post-UV/chlorine process.The enhanced degradation was verified to be attributed to the increased steady-state concentrations of HO^(-)·and ClO_(2)·by Fe(II)addition.Moreover,Fe(II)addition also decreased the ClO_(3)^(–)formation by 53.8%in the UV/chlorine process and its impact on the formation of chloroorganic byproducts was rather minor.The findings demonstrated a promising strategy to improve the drinking water quality and safety by adding low-level Fe(II)in coagulation in an advanced drinking water treatment train.展开更多
Nowadays the protection of the marine environment raises increasing academic and public attention.The issue of organic micropollutants is of equally high importance for the marine ecosystems.Maritime vessels are consi...Nowadays the protection of the marine environment raises increasing academic and public attention.The issue of organic micropollutants is of equally high importance for the marine ecosystems.Maritime vessels are considered to significant sources of micropollutants especially if the ship carries many passengers,which is often true for cruise ships which frequent attractive and sensitive sea areas.The emission pathways for micropollutants include wastewater discharges and sewage sludge disposal.The findings of the German research and development project NAUTEK contribute to bridging the knowledge gap about micropollutant emissions from cruise ships.As expected,micropollutants were detected in both the blackwater and greywater on board,emitted from either the passengers or certain ship operations.In total,16 out of 21 target substances were detected.Peak concentrations of pharmaceuticals could be found mainly in blackwater(peak conc.Carbamazepine 3.9 mg/L,Ibuprofen 29 mg/L,Diclofenac 0.04 mg/L),while greywater is mainly characterized by substances such as ointment residues,UV-filters and flame retardants(peak conc.Diclofenac 0.65 mg/L,Bisphenol A 8 mg/L,Tris(1-chloro-2-propyl)phosphate 136 mg/L).Further analyses suggest a gradual removal of the micropollutants by the onboard MBR plant(MBR effluent peak conc.Carbamazepine 0.47 mg/L,Ibuprofen 6.8 mg/L,Diclofenac 0.3 mg/L).Findings of this research provide a critical stepstone for shaping technical solutions for onboard micropollutants removal and water resource recycling.展开更多
Nitrogen removal is a critical process in water treatment plants(WIPs)and wastewater treatment plants(WWTPs).The recent discovery of a novel bacterial process,complete ammonia oxidation(comammox,CMX),has refuted a cen...Nitrogen removal is a critical process in water treatment plants(WIPs)and wastewater treatment plants(WWTPs).The recent discovery of a novel bacterial process,complete ammonia oxidation(comammox,CMX),has refuted a century-long perception of the two-step conversion of NH3to NO3-.Compared with canonical nitrifiers,CMX bacteria offer undeniable advantages,such as a high growth yield propensity and adaptability to nutrient-and growth-limiting conditions,which collectively draw attention to validate the aptness of CMX bacteria to wastewater treatment.As there has been no comprehensive review on the relevance of CMX bacteria for sustainable water and wastewater treatment,this review is intended to discuss the roles and applications of CMX in the removal of nitrogen and pollutants from water and wastewater.We took into account insights into the metabolic versatilities of CMX bacteria at the clade and subclade levels.We focused on the distribution of CMX bacteria in engineered systems,niche differentiation,co-occurrence and interactions with cano nical nitrifiers for a better understanding of CMX bacteria in terms of their ecophysiology.Conceptualized details on the reactor adaptability and stress response of CMX bacteria are provided.The potential of CMX bacteria to degrade micropollutants either directly or co-metabolically was evaluated,and these insights would be an indispensable advantage in opening the doors for wider applications of CMX bacteria in WWTPs.Finally,we summarized future directions of research that are imperative in improving the understanding of CMX biology.展开更多
The use in agriculture of excreta from urine-diversion toilets can be an alternative solution to the lack of sanitation and high costs of mineral fertilizers inherent to developing countries. The objective of this stu...The use in agriculture of excreta from urine-diversion toilets can be an alternative solution to the lack of sanitation and high costs of mineral fertilizers inherent to developing countries. The objective of this study was to evaluate the hygienic quality of urine used as fertilizer through an ecological sanitation system in Ouagadougou peri-urban areas. Chemical and microbiological analyses were performed in urine samples taken before and after thirty (30) days of storage in jerry cans exposed to sunlight. The concentrations of 7.0 g/l;3.5 and 9.6 g/l of ammonia nitrogen for mean, minimum and maximum respectively, are obtained in unstored urine samples. These concentrations did not practically vary with the storage. On average, values of other chemical parameters analyzed in stored urine were as follows: pH, 8.8;phosphorus (P), 0.3 g/l;potassium (K), 1.9 g/l;total dissolved solids (TDS), 21.0 g/l;cadmium (Cd), 154.3 μg/l;copper (Cu), 5.2 μg/l;lead (Pb), 15.2 μg/l;chromium (Cr), 6.1 μg/l;nickel (Ni), 154.0 μg/l. Escherichia coli, staphylococci, enterococci, Salmonella and spores of Clostridium perfringens were detected in unstored urine samples, with 26% of fecal contamination rate. The time of storage (30 days) under sunlight was enough for almost all bacteria removal in urine samples. Although the fertilizing value of urine was confirmed, it would be important to take account of the best practices on applying in soils, because of the high TDS contents. Also, the risk linked to micropollutants in urine-based fertilizers could be negligible in view of low quantities. The results obtained in this study prove that after 30 days of exposure to sunlight urine collected via eco-toilet becomes bacteriologically sanitized, and can therefore be used to fertilize soils. However, it is necessary to demonstrate the inactivation of other groups of enteric microorganisms in human urine during storage.展开更多
Chlorinated Benzenes (CBs) that were released into the environment contaminate groundwater at many existing and former industrial sites. A research program was initiated to investigate the ecoremediation of CBs contam...Chlorinated Benzenes (CBs) that were released into the environment contaminate groundwater at many existing and former industrial sites. A research program was initiated to investigate the ecoremediation of CBs contaminated groundwater using subsurface flow constructed wetlands. Four lab-scale experiments were performed to evaluate re- moval efficiency with different operation conditions. The first experiment was achieved with two different solid-state materials: a peat and a lava stone (pozzolana). In order to stimulate biological activity, organic matter coming from an aged Vertical Flow Constructed Wetlands (VFCW) was added to the media. Mass balance was determined to assess the fate of these pollutants in this system. The biofiltres of the second experiment were constructed with the same materials but bioaugmentation was realized by adding organic matter of VFCW or by bacteria inoculums. Peat and pozzolana biofiltres planted with Phragmites australis constituted the third experiment to evaluate the effect of plants. Bioaugmen- tation was constituted by the addition of OM coming from aged VFCW. Compost mixed with pozzolana was the solid-state material of the fourth experiment. Columns were made of two stages. The first stage was unplanted and the second stage was planted with Phragmites. Peat has been replaced by compost, a renewable material. Lab-scale biofil- tres remove CBs with an efficiency of 70% - 99%, depending on studied media and conditions. Greater efficiency was observed with bioaugmented media. Volatilization was very low (<0.2%) and the detection of chlorides in water indi- cated the occurrence of biodegradation. The experiments have shown that organic solid-state materials (compost or peat) are useful for groundwater remediation, with higher treatment efficiency than pozzolana material. Bioaugmentation increased biological activity. Clogging of biofiltres have been observed and can be reduced by the presence of plants or by a resting period of 14 - 21 days (requiring alternative feedings on several filters).展开更多
基金supported by the National Natural Science Foundation of China(52221004,52091542,and 51820105011)the Scientific Research Project of China Three Gorges Corporation(201903139)the Research Fund of Vanke School of Public Health(2021JC009),Tsinghua University.
文摘The first pandemic wave of coronavirus disease 2019(COVID-19)induced a considerable increase in several antivirals and antibiotics in surface water.The common symptoms of COVID-19 are viral and bacterial infections,while comorbidities(e.g.,hypertension and diabetes)and mental shock(e.g.,insomnia and anxiety)are nonnegligible.Nevertheless,little is known about the long-term impacts of comorbidities and mental shock on organic micropollutants(OMPs)in surface waters.Herein,we monitored 114 OMPs in surface water and wastewater treatment plants(WWTPs)in Wuhan,China,between 2019 and 2021.The pandemic-induced OMP pollution in surface water was confirmed by significant increases in 26 OMP concentrations.Significant increases in four antihypertensives and one diabetic drug suggest that the treatment of comorbidities may induce OMP pollution.Notably,cotinine(a metabolite of nicotine)increased 155 times to 187 ngL1,which might be associated with increased smoking.Additionally,the increases in zolpidem and sulpiride might be the result of worsened insomnia and depression.Hence,it is reasonable to note that mental-health protecting drugs/behavior also contributed to OMP pollution.Among the observed OMPs,telmisartan,lopinavir,and ritonavir were associated with significantly higher ecological risks because of their limited WWTP-removal rate and high ecotoxicity.This study provides new insights into the effects of comorbidities and mental shock on OMPs in surface water during a pandemic and highlights the need to monitor the fate of related pharmaceuticals in the aquatic environment and to improve their removal efficiencies in WWTPs。
基金supported by the National Natural Science Foundation of China(52222002)Bureau of International Cooperation of Chinese Academy of Sciences(032GJHZ2022035MI)State Key Laboratory of Environmental Aquatic Chemistry(23Z01ESPCR).
文摘The degradation of micropollutants in water via ultraviolet(UV)-based advanced oxidation processes(AOPs)is strongly dependent on the water matrix.Various reactive radicals(RRs)formed in UV-AOPs have different reaction selectivities toward water matrices and degradation efficiencies for target micropollutants.Hence,process selection and optimization are crucial.This study developed a facilitated prediction method for the photon fluence-based rate constant for micropollutant degradation(K′_(p,MP))in various UV-AOPs by combining model simulation with portable measurement.Portable methods for measuring the scavenging capacities of the principal RRs(RRSCs)involved in UV-AOPs(i.e.,HO^(·),SO_(4)^(·-),and Cl^(·))using a mini-fluidic photoreaction system were proposed.The simulation models consisted of photochemical,quantitative structure–activity relationship,and radical concentration steady-state approximation models.The RRSCs were determined in eight test waters,and a higher RRSC was found to be associated with a more complex water matrix.Then,by taking sulfamethazine,caffeine,and carbamazepine as model micropollutants,the k′_(p,MP) values in various UV-AOPs were predicted and further verified experimentally.A lower k′_(p,MP) was found to be associated with a higher RRSC for a stronger RR competition;for example,k′_(p,MP) values of 130.9 and 332.5 m^(2) einstein^(–1),respectively,were obtained for carbamazepine degradation by UV/H_(2)O_(2) in the raw water(RRSC=9.47×10^(4) s^(-1))and sand-filtered effluent(RRSC=2.87×10^(4) s^(-1))of a drinking water treatment plant.The developed method facilitates process selection and optimization for UV-AOPs,which is essential for increasing the efficiency and cost-effectiveness of water treatment.
基金supported by the National Natural Science Foundation of China(52170068 and U21A20161)the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(QAK202108)。
文摘The removal of emerging micropollutants in the aquatic environment remains a global challenge.Conventional routes are often chemically,energetically,and operationally intensive,which decreases their sustainability during applications.Herein,we develop an advanced chemical-free strategy for micropollutants decontamination that is solely based on sequential electrochemistry involving ubiquitous sulfate anions in natural and engineered waters.This can be achieved via a chain reaction initiated by electrocatalytic anodic sulfate(SO_(4)^(2-))oxidation to produce persulfate(S_(2)O_(8)^(2-))and followed by a cathodic persulfate reduction to produce sulfate radicals(SO_(4)^(·-)).These SO_(4)^(·-)are powerful reactive species that enable the unselective degradation of micropollutants and yield SO_(4)^(2-)again in the treated water.The proposed flow-through electrochemical system achieves the efficient degradation(100.0%)and total organic carbon removal(65.0%)of aniline under optimized conditions with a single-pass mode.We also reveal the effectiveness of the proposed system for the degradation of a wide array of emerging micropollutants over a broad pH range and in complex matrices.This work provides the first proof-ofconcept demonstration using ubiquitous sulfate for micropollutants decontamination,making water purification more sustainable and more economical.
基金the National Natural Science Foundation of China (No.50538090)the National Basic Research Program (973) of China (No.2007CB407301)ST Program of Beijing Municipality (No.D0706007040291-01).
文摘Organic micropollutants,with high toxicity and environmental concern,are present in the landfill leachate at much lower levels than total organic constituents (chemical oxygen demand (COD),biochemical oxygen demand (BOD),or total organic carbon (TOC)),and few has been known for their behaviors in different treatment processes.In this study,occurrence and removal of 17 organochlorine pesticides (OCPs),16 polycyclic aromatic hydrocarbons (PAHs),and technical 4-nonylphenol (4-NP) in landfill leachate in a comb...
文摘Micropollutants are defined as contaminants found in trace concentrations in water bodies that are persistent and bioactive, meaning they are not completely biodegradable and cannot be removed by conventional water treatment methods. Because of these aspects, their detection and removal pose a challenge to the scientific community. Among them are endocrine disruptors, drugs, agricultural chemicals, personal grooming products, industrial additives and others. These micropollutants are the cause for global concern, because their presence in water supply systems is suspected of causing health problems in humans and animals. To develop efficient techniques to remove them, it is fundamental to understand their physico-chemical properties and the available treatment types and conditions. Membrane separation processes (MSPs) and advanced oxidation processes (AOPs) are the focus of this literature review, as potential treatment methods to remove micropollutants. The former process stands out for high rejection rates (above 90%) of various micropollutants, but it generates a concentrated secondary waste stream. In turn, the latter process can remove micropollutants without generating secondary wastes, and can also be applied and combined with other treatment methods.
基金supported by the National Key R&D Program of China(2022YFC3203701)the National Natural Science Foundation of China(52070185)+1 种基金the Fellowship of China Postdoctoral Science Foundation(2022M723320)the Department of Water Management of TU Delft.
文摘Activated carbon is employed for the adsorption of organic micropollutants(OMPs)from water,typically present in concentrations ranging from ng L1 to mg L1.However,the efficacy of OMP removal is considerably deteriorated due to competitive adsorption from background dissolved organic matter(DOM),present at substantially higher concentrations in mg L1.Interpreting the characteristics of competitive DOM is crucial in predicting OMP adsorption efficiencies across diverse natural waters.Molecular weight(MW),aromaticity,and polarity influence DOM competitiveness.Although the aromaticity-related metrics,such as UV254,of low MW DOM were proposed to correlate with DOM competitiveness,the method suffers from limitations in understanding the interplay of polarity and aromaticity in determining DOM competitiveness.Here,we elucidate the intricate influence of aromaticity and polarity in low MW DOM competition,spanning from a fraction level to a compound level,by employing direct sample injection liquid chromatography coupled with ultrahigh-resolution Fouriertransform ion cyclotron resonance mass spectrometry.Anion exchange resin pre-treatment eliminated 93%of UV254-active DOM,predominantly aromatic and polar DOM,and only minimally alleviated DOM competition.Molecular characterization revealed that nonpolar molecular formulas(constituting 26%PAC-adsorbable DOM)with medium aromaticity contributed more to the DOM competitiveness.Isomerlevel analysis indicated that the competitiveness of highly aromatic LMW DOM compounds was strongly counterbalanced by increased polarity.Strong aromaticity-derived p-p interaction cannot facilitate the competitive adsorption of hydrophilic DOM compounds.Our results underscore the constraints of depending solely on aromaticity-based approaches as the exclusive interpretive measure for DOM competitiveness.In a broader context,this study demonstrates an effect-oriented DOM analysis,elucidating counterbalancing interactions of DOM molecular properties from fraction to compound level.
基金gratefully appreciate the support offered by the KFUPM Fund received from Mr.Al-Bin Saleh donated through project MWS-90130027 to the Interdisciplinary Research Center for Membranes and Water Security,King Fahd University of Petroleum and Minerals,Saudi Arabia.
文摘Chemistry of the polyamide active layer of a desalination membrane is critical in determining both its physical and chemical properties.In this study,we designed and fabricated three novel membranes with different active layers using the crosslinkers:terephthaloyl chloride,isophthaloyl chloride,and trimesoyl chloride.The crosslinkers were reacted with an aqueous solution of an aliphatic tetra-amine.Because these crosslinkers differ in their structures and crosslinking mechanisms during interfacial polymerization,the resultant membranes also possess different structural properties.The water contact angle of the fabricated membranes also varies;the water contact angles of 4A-3P-TPC@PSF/PET,4A-3P-TMC@PSF/PET,and 4A-3P-IPC@PSF/PET,are 68.9°,65.6°,and 53.9°,respectively.Similarly,the desalination performance of resultant membranes also showed variations,with 4A-3P-TPC@PSF/PET,4A-3P-IPC@PSF/PET,and 4A-3P-TMC@PSF/PET having a permeate flux of 17.14,25.70,and 30.90 L·m^(−2)·h^(−1),respectively,at 2.5 MPa.The 4A-3P-TPC@PSF/PET membrane exhibited extensive crosslinking with aliphatic linear amine,and cationic dye rhodamine B,MgCl_(2),and amitriptyline rejection rates of 98.6%,92.7%and 80.9%,respectively.The 4A-3P-TMC@PSF/PET membrane showed mediocre performance,while 4A-3P-IPC@PSF/PET membrane showed even lower performance,with a 35%rejection of methyl orange dye.
基金the National Key R&D Program of China(No.2018YFE0204101)the National Natural Science Foundation of China(No.51778603)the Alliance of International Science Organizations(ANSO-CR-KP-2020-05).
文摘Backwashing is crucial for preventing clogging of sand filters.However,few studies have investigated the effect of backwashing on micropollutant removal and the dynamic changes in the microbial community in sand filters.Here,we used a series of manganese and quartz sand filters under empty bed contact times(EBCTs)of 2 h and 4 h to explore variations in micropollutant degradation and temporal dynamics of the microbial community after backwashing.The results showed that the removal efficiencies of caffeine,sulfamethoxazole,sulfadiazine,trimethoprim,atrazine,and active biomass recovered within 2 d after backwashing in both types of sand filters at 2-h EBCT,but the recovery of sulfadiazine and trimethoprim was not observed at 4-h EBCT.Moreover,the removal efficiency of atenolol increased after backwashing in the manganese sand filters,whereas maintained almost complete removal efficiency in the quartz sand filters at both EBCTs.Pearson correlation analysis indicated that microbial community composition gradually recovered to the pre-backwashing level(R increased from 0.53 to 0.97)at 2-h EBCT,but shifted at 4-h EBCT(R<0.25)after backwashing.Furthermore,the compositions of the recovered,depleted,and improved groups of microbes were distinguished by applying hierarchical clustering to the differentially abundant amplicon sequence variants.The cumulative relative abundance of recovered microbes at 2-h EBCT was 82.76%±0.43%and 46.82%±4.34%in the manganese and quartz sand filters,respectively.In contrast,at 4-h EBCT,the recovered microbes dropped to 15.55%–25.69%in both types of sand filters.
基金supported by the Major Science and Technology Program for Water Pollution Control and Treatment in China(No.2017ZX07106005)
文摘To perform a systematic survey on the occurrence and removal of micropollutants during municipal wastewater treatment, 943 semi-volatile organic chemicals in 32 wastewater samples including influents of secondary treatments, secondary effluents and final effluents(effluents of advanced treatments), which were collected from seven full-scale municipal wastewater treatment plants(MWTPs) in China, were examined by gas chromatography-mass spectrometry(GC-MS) coupled with an automated identification and quantification system with a database(AIQS-DB). In total, 196 and 145 chemicals were detected in secondary and final effluents, respectively. The majority of the total concentrations(average removal efficiency, 87.0%±5.9%) of the micropollutants were removed during secondary treatments. However, advanced treatments achieved different micropollutant removal extents from secondary effluents depending on the different treatment processes employed. Highly variable removal efficiencies of total concentrations(32.7%–99.3%) were observed among the different advanced processes. Among them,ozonation-based processes could remove 70.0%–80.9% of the total concentrations of studied micropollutants. The potentially harmful micropollutants, based on their detection frequency and concentration in secondary and final effluents, were polycyclic aromatic hydrocarbons(PAHs)(2-methylnaphthalene, fluoranthene, pyrene, naphthalene and phenanthrene), phosphorus flame retardants(tributyl phosphate(TBP), tris(2-chloroethyl)phosphate(TCEP) and tris(1,3-dichloro-2-propyl) phosphate(TDCP)), phthalates(bis(2-ethylhexyl)phthalate(DEHP)), benzothiazoles(benzothiazole,2-(methylthio)-benzothiazol, and 2(3H)-benzothiazolone) and phenol. This study indicated that the presence of considerable amounts of micropollutants in secondary effluent creates the need for suitable advanced treatment before their reuse.
文摘A rapid and effective method based on a novel permanent magnetic hypercrosslinked resin W150 was proposed for the removal of organic micropollutants in drinking water. W150 was prepared by suspension and post-crosslinking reaction and found to possess a high specific surface area of 1149.7 m^2· g^-1, a small particle size of 50 μm to 100 μm, and a saturation magnetization as high as 8 emu.g1. W150 was used to eliminate nitrofurazone (NFZ) and oxytetracycline (OTC) from drinking water compared with commercial adsorbents XAD-4 and F400D. The adsorption kinetics of NFZ and OTC onto the three adsorbents well fitted the pseudo-second-order equation (r 〉 0.972), and the adsorption isotherms were all well described by the Freundlich equation (r 〉 0.851). Results showed that the reduction in adsorbent size and the enlargement in sorbent pores both accelerated adsorption. Moreover, the effect of particle size on adsorption was more significant than that of pore width. Given that the smallest particle size and the highest specific surface area were possessed by W150, it had the fastest adsorption kinetics and largest adsorption capacity for NFZ (180 mg·g-1) and OTC (200mg·g- 1). For the adsorbents with dominant micropores, the sorption of large-sized adsorbates decreased because of the inaccessible micropores. The solution pH and ionic strength also influenced adsorption.
基金the National Key Research and Development Program of China(No.2016YFA0203200)the National Natural Science Foundation of China(Nos.21721003 and 21874127)K.C.Wong Education Foundation.
文摘The performance of water purification by adsorption method has been limited owing to the fact that most of current available adsorbents fail to achieve satisfactory removal performance for organic micropollutants.Herein,we report the design and synthesis of novel porous polymeric adsorbent built fromβ-cyclodextrin(B-CD),in whichβ-CD molecules are arranged in an ordered bis(β-CD)tubular assemblies.The induction of bis(B-CD)units renders them high adsorption affinity toweard bisphenols(bisphenol A and its analogues bisphenol B,bisphenol F and bisphenol S),the typical endocrine disruptors,via the formation of stable host-guest inclusion complexes in aquatic systems.In combination with their high porosity(Brunauer-Emmett-Teller(BET)surface area of 150 m2·g-1),abundantβ-CD content and fast sorption kinetics,the obtained adsorbent outperforms commercial water purifier in elimination of bisphenol micropollutants from potable water.Our work may open a new avenue for designing highly eficient adsorbents for removal of organic micropollutants from aquatic systems.
基金This work was supported by the National Natural Science Foundation of China(Nos.51778522,51708447)Shaanxi Provincial Program for Innovative Research Team(No.2019TD-025)+1 种基金the National Science Foundation of Shaanxi Province(No.2020JQ-663)the Research Fund of Xi’an University of Architecture and Technology(No.ZR18025).
文摘Currently,the wastewater treatment plants(WWTPs)attempt to achieve the shifting from general pollution parameters control to reduction of organic micropollutants discharge.However,they have not been able to satisfy the increasing ecological safety needs.In this study,the removal of micropollutants was investigated,and the ecological safety was assessed for a local WWTP.Although the total concentration of 31 micropollutants detected was reduced by 83%using the traditional biological treatment processes,the results did not reflect chemicals that had poor removal efficiencies and low concentrations.Of the five categories of micropollutants,herbicides,insecticides,and bactericides were difficult to remove,pharmaceuticals and UV filters were effectively eliminated.The specific photosynthesis inhibition effect and non-specific bioluminescence inhibition effect from wastewater were detected and evaluated using hazardous concentration where 5%of aquatic organisms are affected.The photosynthesis inhibition effect from wastewater in the WWTP was negligible,even the untreated raw wastewater.However,the bioluminescence inhibition effect from wastewater which was defined as the priority biological effect,posed potential ecological risk.To decrease non-specific biological effects,especially of macromolecular dissolved organic matter,overall pollutant reduction strategy is necessary.Meanwhile,the ozonation process was used to further decrease the bioluminescence inhibition effects from the secondary effluent;≥0.34 g O 3/g DOC of ozone dose was recommended for micropollutants elimination control and ecological safety.
基金supported by the National Natural Science Foundation of China(No.21775118)Shaanxi Natural Science Basic Research Project(No.2018JM2018)+2 种基金Youth Innovation Team of Shaanxi Universities(No.2019.21)Young Outstanding Talent Support Program of Shaanxi UniversitiesXi’an Shiyou University Youth Research and Innovation Team Construction Plan(No.2019QNKYCXTD17),and Xi’an Shiyou University Graduate Innovation and Practice Ability Training Project(No.YCS19211016)。
文摘The combination of hologram quantitative structure-activity relationship(HQSAR)and consensus modeling was employed to study the quantitative structure-property relationship(QSPR)model for calculating the aqueous hydroxyl radical oxidation reaction rate constants(kOH)of organic micropollutants(OMPs).Firstly,individual HQSAR model were established by using standard HQSAR method.The optimal individual HQSAR model was obtained while setting the parameter of fragment distinction and fragment size to“B”and“3~6”respectively.Secondly,consensus HQSAR model was established by building the regression model between the kOH and the hologram descriptors with consensus partial least-squares(cPLS)approach.The obtained individual and consensus HQSAR model were validated with a randomly selected external test set.The result of external test set validation demonstrates that both individual and consensus HQSAR model are available for predicting the kOH of OMPs.Compared with the optimal individual HQSAR model,the established consensus HQSAR model shows higher prediction accuracy and robustness.It is shown that the combination of HQSAR and consensus modeling is a practicable and promising method for studying and predicting the kOH of OMPs.
基金supported by the National Natural Science Foundation of China (No.41772264)the Applied Basic Research Programs of Science and Technology Foundation of Sichuan Province (No.18YYJC1745)the Research Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection (No.SKLGP2018Z001)。
文摘The degradation of pharmaceutical micropollutants is an intensifying environmental problem and synthesis of efficient photocatalysts for this purpose is one of the foremost challenges worldwide.Therefore,this study was conducted to develop novel plasmonic Ag/Ag2O/BiVO4 nanocomposite photocatalysts by simple precipitation and thermal decomposition methods,which could exhibit higher photocatalytic activity for mineralized pharmaceutical micropollutants.Among the different treatments,the best performance was observed for the Ag/Ag2O/BiVO4 nanocomposites (5 wt.%;10 min’s visible light irradiation)which exhibited 6.57 times higher photodegradation rate than the pure BiVO4.Further,the effects of different influencing factors on the photodegradation system of tetracycline hydrochloride (TC-HCl) were investigated and the feasibility for its practical application was explored through the specific light sources,water source and cycle experiments.The mechanistic study demonstrated that the photogenerated holes (h^+),superoxide radicals (·O2^-)and hydroxyl radicals (·OH) participated in TC-HCl removal process,which is different from the pure BiVO4 reaction system.Hence,the present work can provide a new approach for the formation of novel plasmonic photocatalysts with high photoactivity and can act as effective practical application for environmental remediation.
基金funding support through the project DP 170104330the support by Australian Research Council Future Fellowship(FT170100196).
文摘The ubiquity of micropollutants(MPs)in aquatic environments has attracted increasing concern for public health and ecological security.Compared to conventional biological treatment,photocatalytic processes show more efficiency in degrading MPs,but they require expensive materials and complicated synthesis processes.This study developed an economic photocatalytic process to degrade micropollutants.We synthesized urea-based graphitic carbon nitride(g-C_(3)N_(4))by a facile one-step pyrolysis method and evaluated the photocatalytic efficiency of carbamazepine(CBZ).Under simulated solar irradiation,g-C_(3)N_(4) could achieve 100% removal efficiency of 0.1 mg/L CBZ in spiked wastewater effluent within 15 min,and 86.5% removal efficiency in wastewater influent after 20 min of irradiation.The porous structure of g-C_(3)N_(4) promoted effective charge separation and mass transport of CBZ near the catalyst surface,enabling a high kinetic rate(0.3662 min^(-1)).Reactive oxygen species trapping experiments revealed that superoxide radicals(O_(2)^(·-))and holes(h^(+))were the major active radicals.Electron paramagnetic resonance(EPR)further confirmed the presence of O_(2)^(·-),·OH,^(1)O_(2) and holes.The pH,light intensity and initial CBZ concentration were found to have significant impacts on the removal efficiency of CBZ.Possible reaction intermediates were identified and the degradation pathway was proposed.Multiple MPs were selected to further demonstrate photocatalytic efficiency of g-C_(3)N_(4).The facile synthesis,superior efficiency,and versatility of g-C_(3)N_(4) make it a promising catalyst for application in tertiary wastewater treatment processes.
基金supported by the Hong Kong Innovation and Technology Fund (No. GHP/010/18GD)the National Natural Science Foundation of China (No. 21876210)+1 种基金the Hong Kong Research Grants Council (No. T21-604/19-R)partially supported by a fellowship award from the Research Grants Council of the Hong Kong Special Administrative Region, China (No. HKUST PDFS2021-6S05)。
文摘Drinking water utilities are interested in upgrading their treatment facilities to enhance micropollutant removal and byproduct control.Pre-oxidation by chlorine dioxide(ClO_(2))followed by coagulation-flocculation-sedimentation and advanced oxidation processes(AOPs)is one of the promising solutions.However,the chlorite(ClO_(2)^(-))formed from the ClO_(2) preoxidation stage cannot be removed by the conventional coagulation process using aluminum sulfate.ClO_(2)^(–)negatively affects the post-UV/chlorine process due to its strong radical scavenging effect,and it also enhances the formation of chlorate(ClO_(3)^(–)).In this study,dosing micromolar-level ferrous iron(Fe(II))into aluminum-based coagulants was proposed to eliminate the ClO_(2)^(–)generated from ClO_(2) pre-oxidation and benefit the post-UV/chlorine process in radical production and ClO_(3)^(–)reduction.Results showed that the addition of 52.1-μmol/L FeSO_(4) effectively eliminated the ClO_(2)^(-)generated from the pre-oxidation using 1.0 mg/L(14.8μmol/L)of ClO 2.Reduction of ClO_(2)^(-)increased the degradation rate constant of a model micropollutant(carbamazepine)by 55.0%in the post-UV/chlorine process.The enhanced degradation was verified to be attributed to the increased steady-state concentrations of HO^(-)·and ClO_(2)·by Fe(II)addition.Moreover,Fe(II)addition also decreased the ClO_(3)^(–)formation by 53.8%in the UV/chlorine process and its impact on the formation of chloroorganic byproducts was rather minor.The findings demonstrated a promising strategy to improve the drinking water quality and safety by adding low-level Fe(II)in coagulation in an advanced drinking water treatment train.
基金This work was supported by the German Federal Ministry of Economic Affairs and Energy(BMWi)in the Project NAUTEK Sustainable Wastewater Treatment and Recycling on Cruise Liners(Grant No.03SX360)upon a decision of the German Bundestag.We appreciate the support from the funding agency for the possibility to carry out the work described here.We also thank the ships'crews for their great support.
文摘Nowadays the protection of the marine environment raises increasing academic and public attention.The issue of organic micropollutants is of equally high importance for the marine ecosystems.Maritime vessels are considered to significant sources of micropollutants especially if the ship carries many passengers,which is often true for cruise ships which frequent attractive and sensitive sea areas.The emission pathways for micropollutants include wastewater discharges and sewage sludge disposal.The findings of the German research and development project NAUTEK contribute to bridging the knowledge gap about micropollutant emissions from cruise ships.As expected,micropollutants were detected in both the blackwater and greywater on board,emitted from either the passengers or certain ship operations.In total,16 out of 21 target substances were detected.Peak concentrations of pharmaceuticals could be found mainly in blackwater(peak conc.Carbamazepine 3.9 mg/L,Ibuprofen 29 mg/L,Diclofenac 0.04 mg/L),while greywater is mainly characterized by substances such as ointment residues,UV-filters and flame retardants(peak conc.Diclofenac 0.65 mg/L,Bisphenol A 8 mg/L,Tris(1-chloro-2-propyl)phosphate 136 mg/L).Further analyses suggest a gradual removal of the micropollutants by the onboard MBR plant(MBR effluent peak conc.Carbamazepine 0.47 mg/L,Ibuprofen 6.8 mg/L,Diclofenac 0.3 mg/L).Findings of this research provide a critical stepstone for shaping technical solutions for onboard micropollutants removal and water resource recycling.
基金supported by the National Natural Science Foundation of China(52000185 and 51878675)Key Research and Development Program of Shandong Province(2019JZZY020308)China Postdoctoral Science Foundation,China(2017M612807)。
文摘Nitrogen removal is a critical process in water treatment plants(WIPs)and wastewater treatment plants(WWTPs).The recent discovery of a novel bacterial process,complete ammonia oxidation(comammox,CMX),has refuted a century-long perception of the two-step conversion of NH3to NO3-.Compared with canonical nitrifiers,CMX bacteria offer undeniable advantages,such as a high growth yield propensity and adaptability to nutrient-and growth-limiting conditions,which collectively draw attention to validate the aptness of CMX bacteria to wastewater treatment.As there has been no comprehensive review on the relevance of CMX bacteria for sustainable water and wastewater treatment,this review is intended to discuss the roles and applications of CMX in the removal of nitrogen and pollutants from water and wastewater.We took into account insights into the metabolic versatilities of CMX bacteria at the clade and subclade levels.We focused on the distribution of CMX bacteria in engineered systems,niche differentiation,co-occurrence and interactions with cano nical nitrifiers for a better understanding of CMX bacteria in terms of their ecophysiology.Conceptualized details on the reactor adaptability and stress response of CMX bacteria are provided.The potential of CMX bacteria to degrade micropollutants either directly or co-metabolically was evaluated,and these insights would be an indispensable advantage in opening the doors for wider applications of CMX bacteria in WWTPs.Finally,we summarized future directions of research that are imperative in improving the understanding of CMX biology.
文摘The use in agriculture of excreta from urine-diversion toilets can be an alternative solution to the lack of sanitation and high costs of mineral fertilizers inherent to developing countries. The objective of this study was to evaluate the hygienic quality of urine used as fertilizer through an ecological sanitation system in Ouagadougou peri-urban areas. Chemical and microbiological analyses were performed in urine samples taken before and after thirty (30) days of storage in jerry cans exposed to sunlight. The concentrations of 7.0 g/l;3.5 and 9.6 g/l of ammonia nitrogen for mean, minimum and maximum respectively, are obtained in unstored urine samples. These concentrations did not practically vary with the storage. On average, values of other chemical parameters analyzed in stored urine were as follows: pH, 8.8;phosphorus (P), 0.3 g/l;potassium (K), 1.9 g/l;total dissolved solids (TDS), 21.0 g/l;cadmium (Cd), 154.3 μg/l;copper (Cu), 5.2 μg/l;lead (Pb), 15.2 μg/l;chromium (Cr), 6.1 μg/l;nickel (Ni), 154.0 μg/l. Escherichia coli, staphylococci, enterococci, Salmonella and spores of Clostridium perfringens were detected in unstored urine samples, with 26% of fecal contamination rate. The time of storage (30 days) under sunlight was enough for almost all bacteria removal in urine samples. Although the fertilizing value of urine was confirmed, it would be important to take account of the best practices on applying in soils, because of the high TDS contents. Also, the risk linked to micropollutants in urine-based fertilizers could be negligible in view of low quantities. The results obtained in this study prove that after 30 days of exposure to sunlight urine collected via eco-toilet becomes bacteriologically sanitized, and can therefore be used to fertilize soils. However, it is necessary to demonstrate the inactivation of other groups of enteric microorganisms in human urine during storage.
文摘Chlorinated Benzenes (CBs) that were released into the environment contaminate groundwater at many existing and former industrial sites. A research program was initiated to investigate the ecoremediation of CBs contaminated groundwater using subsurface flow constructed wetlands. Four lab-scale experiments were performed to evaluate re- moval efficiency with different operation conditions. The first experiment was achieved with two different solid-state materials: a peat and a lava stone (pozzolana). In order to stimulate biological activity, organic matter coming from an aged Vertical Flow Constructed Wetlands (VFCW) was added to the media. Mass balance was determined to assess the fate of these pollutants in this system. The biofiltres of the second experiment were constructed with the same materials but bioaugmentation was realized by adding organic matter of VFCW or by bacteria inoculums. Peat and pozzolana biofiltres planted with Phragmites australis constituted the third experiment to evaluate the effect of plants. Bioaugmen- tation was constituted by the addition of OM coming from aged VFCW. Compost mixed with pozzolana was the solid-state material of the fourth experiment. Columns were made of two stages. The first stage was unplanted and the second stage was planted with Phragmites. Peat has been replaced by compost, a renewable material. Lab-scale biofil- tres remove CBs with an efficiency of 70% - 99%, depending on studied media and conditions. Greater efficiency was observed with bioaugmented media. Volatilization was very low (<0.2%) and the detection of chlorides in water indi- cated the occurrence of biodegradation. The experiments have shown that organic solid-state materials (compost or peat) are useful for groundwater remediation, with higher treatment efficiency than pozzolana material. Bioaugmentation increased biological activity. Clogging of biofiltres have been observed and can be reduced by the presence of plants or by a resting period of 14 - 21 days (requiring alternative feedings on several filters).