Bisphenol A （BPA） is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A nov...Bisphenol A （BPA） is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3, prepared from hexagonal SBA- 15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon （PAC）. Characterization of CMK-3 by transmission electron microscopy （TEM）, X-ray diffraction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m^2/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/（mg.min）, much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40℃. No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9 to 13.展开更多
The 6：2 FTS was the substitute for perfluorooctane sulfonate（PFOS） in the chrome plating industry in Japan. Electrochemical oxidation of 6：2 FTS was investigated in this study. The degradabilities of PFOS and 6：2...The 6：2 FTS was the substitute for perfluorooctane sulfonate（PFOS） in the chrome plating industry in Japan. Electrochemical oxidation of 6：2 FTS was investigated in this study. The degradabilities of PFOS and 6：2 FTS were tested on the Ti/SnO2–Sb2O5–Bi2O3anode. The effects of current density,potential,and supporting electrolyte on the degradation of 6：2 FTS were evaluated. Experimental results showed that 6：2 FTS was more easily degraded than PFOS on the Ti/SnO2–Sb2O5–Bi2O3anode. At a low current density of 1.42 mA/cm2,6：2 FTS was not degraded on Ti/SnO2–Sb2O5–Bi2O3,while the degradation ratio increased when the current density ranged from 4.25 to 6.80 mA/cm2. The degradation of 6：2 FTS at current density of 6.80 mA/cm2 followed pseudo first-order kinetics with the rate constant of 0.074 hr-1. The anodic potential played an important role in the degradation of 6：2 FTS,and the pseudo first-order rate constants increased with the potential. The surface of Ti/SnO2–Sb2O5–Bi2O3was contaminated after electrolysis at constant potential of 3 V,while the fouling phenomenon was not observed at 5 V. The fouled anode could be regenerated by incinerating at 600°C. The intermediates detected by ultra-performance liquid chromatography coupled with a triple-stage quadrupole mass spectrometer（UPLC–MS/MS） were shorter chain perfluorocarboxylic acids. The 6：2 FTS was first attacked by hydroxyl radical,and then formed perfluorinated carboxylates,which decarboxylated and removed CF2 units to yield shorter-chain perfluorocarboxylic acids.展开更多
Highly persistent per-and polyfluorinated alkyl substances(PFAS)have been extensively used worldwide for decades and are now ubiquitous in the ecosystem.To combat problems related to PFAS accumulation in the environme...Highly persistent per-and polyfluorinated alkyl substances(PFAS)have been extensively used worldwide for decades and are now ubiquitous in the ecosystem.To combat problems related to PFAS accumulation in the environment and their intrusion into the human body,PFAS adsorption and subsequent breakdown of carbon and fluorine chains are under intense research.Activated carbon(AC)is a widely used adsorbent for PFAS removal from water or wastewater.However,some of its shortcomings include inefficiency in short-chain PFAS removal,a lack of selectivity,overall low adsorption performance,and concerns regarding economic sustainability.Herein,we reviewed the recent innovative carbon-based technologies that aim to address these challenges.In particular,we focus on AC’s topography engineering,defunctionalization(e.g.,removing surface functional groups),hydrophobicity or surface charge modification,water-confining nanopores,and ACnanobubbles synergy.The underlying mechanisms of these novel approaches and their effectiveness in PFAS adsorption are discussed,along with their advancements and limitations.Additionally,the PFAS adsorption and regeneration ability of high-performance ACs are presented and compared.Finally,we address current challenges and offer perspectives on advancing this technology.展开更多
Rapidly increasing concentration of CO2 in the atmosphere has drawn more and more attention in recent years, and adsorption has been considered as an effective technology for CO2 capture from the anthropogenic sources...Rapidly increasing concentration of CO2 in the atmosphere has drawn more and more attention in recent years, and adsorption has been considered as an effective technology for CO2 capture from the anthropogenic sources. In this paper, the attractive adsorbents including activated carbons and amine-modified materials were mainly reviewed and discussed with particular attention on progress in the adsorbent preparation and C02 adsorption capacity. Carbon materials can be prepared from different precursors including fossil fuels, biomass and resins using the carbonization-activation or only activation process, and activated carbons prepared by KOH activation with high CO2 adsorbed amount were reviewed in the preparation, adsorption capacity as well as the relationship between the pore characteristics and CO2 adsorption. For the amine-modified materials, the physical impregnation and chemical graft of polyethylenimine （PEI） on the different porous materials were introduced in terms of preparation method and adsorption perfor- mance as well as their advantages and disadvantages for CO2 adsorption. In the last section, the issues and prospect of solid adsorbents for CO2 adsorption were summarized, and it is expected that this review will be helpful for the fundamental studies and industrial applications of acti- vated carbons and amine-modified adsorbents for CO2 capture.展开更多
The application of appropriate advanced treat- ment process in the municipal wastewater treatment plants （WWTPs） has become an important issue considering the elimination of emerging contaminants, such as pharma- ce...The application of appropriate advanced treat- ment process in the municipal wastewater treatment plants （WWTPs） has become an important issue considering the elimination of emerging contaminants, such as pharma- ceutical and personal care products （PPCPs）. In the present study, the removal of 13 PPCPs belonging to different therapeutic classes by the sequential ultraviolet （UV） and ozonation process in a full-scale WWTP in Beijing was investigated over the course of ten months. Most of the target PPCPs were effectively removed, and the median removal efficiencies of individual PPCPs, ranging from -13% to 89%, were dependent on their reaction rate constants with molecular ozone. Noticeable fluctuation in the removal efficiencies of the same PPCPs was observed in different sampling campaigns. Nevertheless, the sequential UV and ozonation process still made a significant contribution to the total elimination of most PPCPs in the full-scale WWTP, by compensating for the poor or fluctuant removal performance of PPCPs by biologic treatment process.展开更多
The Stockholm Convention on persistent organic pollutants （POPs） was adopted in 2001. This year is the 10th anniversary of the adoption of the Convention. Until now, 22 chemicals or chemical categories have been lis...The Stockholm Convention on persistent organic pollutants （POPs） was adopted in 2001. This year is the 10th anniversary of the adoption of the Convention. Until now, 22 chemicals or chemical categories have been listed as POPs in the Stockholm Convention. The POPs Research Center was established in Tsinghua University in the same year when the Convention was adopted. In the last ten years, much work has been done by Chinese researchers to understand the environ- mental risk of POPs in China. This article aims to review the recent research progress of our POPs Research Center and some other Chinese researchers＇ studies in addressing the environmental risk of POPs, including the priority screening and inventory study of POPs, monitoring and modeling of POPs pollution and exposure, and environ- mental risk assessment and modeling of POPs. Although great advances in addressing the environmental risk of POPs have been made in recent years, we are still facing quite a few problems, such as data scarcity and uncertainty in environmental risk assessment of POPs. The study on the effect of POPs mixtures is in its infancy and currently POPs are usually assessed from legal perspective by risk assessment of single chemicals. These problems should be well addressed by further efforts. Further studies should also be taken in future to study environment risk of POPs by considering aspects of coupled dynamics between climate processes and POPs. Such sound scientific, riskbased information can support decision-making aiming to effectively minimize the risk level of POPs.展开更多
Effective recovery of high-value heavy metals from electroplating wastewater is of great significance,but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported.In this study,...Effective recovery of high-value heavy metals from electroplating wastewater is of great significance,but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported.In this study,the pilot-scale fixed-bed resin adsorption was conducted to recover Ni(Ⅱ)ions from real nickel plating wastewater,and then the concentrated Ni(Ⅱ)ions in the regenerated solution were reduced to nickel sheet via electrodeposition.A commercial cation-exchange resin was selected and the optimal resin adsorption and regeneration conditions were investigated.The resin exhibited an adsorption capacity of 63 mg/g for Ni(Ⅱ)ions,and the average amount of treated water was 84.6 bed volumes(BV)in the pilot-scale experiments.After the adsorption by two ion-exchange resin columns in series and one chelating resin column,the concentrations of Ni(Ⅱ)in the treated wastewater were below 0.1 mg/L.After the regeneration of the spent resin using 3 BVof 4%(w/w)HC1 solution,1.5 BV of concentrated neutral nickel solution(>30 g/L)was obtained and used in the subsequent electrodeposition process.Using the aeration method,alkali and water required in resin activation process were greatly reduced to 2 BV and 3 BV,respectively.Under the optimal electrodeposition conditions,95.6%of Ni(Ⅱ)in desorption eluent could be recovered as the elemental nickel on the cathode,llie total treatment cost for the resin adsorption and regeneration as well as the electrodeposition was calculated.展开更多
Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose ...Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose using conventional techniques.Sorption may be an attractive method to remove it from water.In this study,the molecularly imprinted polymer(MIP)adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate(PFOS)from water.The MIP adsorbents using perfluorooctanoic acid(PFOA)as the template had good imprinting effects and could selectively remove PFOS from aqueous solution.The sorption behaviors including sorption kinetics,isotherms,and effect of pH,salt,and competitive anions were investigated.Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast,pHdependent,and highly selective.The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents.The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations,which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface.The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS.The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.展开更多
This review paper summarizes the occurrence,removal and ecological risk of contaminants of emerging concern(CEC)reported in landfill leachate in China since 1996(43 studies in 10 regions).Results show that many more s...This review paper summarizes the occurrence,removal and ecological risk of contaminants of emerging concern(CEC)reported in landfill leachate in China since 1996(43 studies in 10 regions).Results show that many more studies are conducted in developed southeastern China than in developing western and northeastern regions in China.Phthalate esters(PAEs,with 15 studies)and pharmaceuticals and personal care products(PPCPs,with 13 studies)are the two most frequently studied CEC classes.Concentrations of nine CECs classes were in a wide range from 0.03(organochlorine pesticides)to approximately 4500 mg/L(alkylphenol polyethoxylates/bisphenol analog).Meanwhile,concentrations of CEC compounds range from below detection limit(e.g.doxycycline)to approximately 4500 mg/L(bisphenol A).Several PAEs(diethyl phthalate,di-n-butyl phthalate,and di(2-ethylhexyl)phthalate)and PPCPs(diclofenac and gemfibrizol)have significant variation between sampling sites.Typically,advanced treatment processes can achieve higher removal efficiencies of CEC compounds from landfill leachate compared with conventional treatment processes.Furthermore,environmental risk assessments of CEC compounds in treated landfill leachate using a risk quotient method show that 2(substituted)polycyclic aromatic hydrocarbons(sPAHs)(benzo(a)anthracene and benzo(b)fluoranthene),2 PPCPs(bezafibrate and sulfapyridine),g-hexachlorocyclohexane,and bisphenol A pose high risk.The importance of monitoring and potential risks of CECs in the leachate to vicinity aquatic environment cross China is addressed.展开更多
Pharmaceuticals and personal care products(PPCPs)have received increasing attention.However,their transformation products(TPs)and metabolites,sometimes even with environmental concentration and/or toxicity higher than...Pharmaceuticals and personal care products(PPCPs)have received increasing attention.However,their transformation products(TPs)and metabolites,sometimes even with environmental concentration and/or toxicity higher than their parent compounds,received attention far from enough.This study gives useful insight on the occurrence,fate and toxicity of PPCP TPs or metabolites in WWTPs,surface water and even drinking water,highlighting the necessity of studying the PPCP TPs formation,occurrence,toxicity and environment risk,and further evaluating the environmental risk caused by PPCPs comprehensively.展开更多
The fate and removal of pharmaceuticals and personal care products （PPCPs） in wastewater treatment plants （WWTPs） has received great attention during the last decade. Numerous data concerning concentrations in the...The fate and removal of pharmaceuticals and personal care products （PPCPs） in wastewater treatment plants （WWTPs） has received great attention during the last decade. Numerous data concerning concentrations in the water phase can be found in the literature, however corresponding data from sludge as well as associated mass balance calculations are very limited. In the present study, the adsorbed and dissolved concentrations of 9 PPCPs were investigated in each unit of a WWTP in Beijing, China. Based on the calculation of mass balance, the relative mass distribution and removal efficiency of each target compound was obtained at each process. The amount of PPCPs entering into the WWTP ranged from 12 g·d^-1 to 3848 g·d^-1. Five target compounds （caffeine, chloramphenicol, bezafibrate, clofibric acid, and N,N- diethyl-meta-toluamide） were effectively removed, with rates of 57%-100%. Negative removal efficiencies were obtained for sulpiride, metoprolol, nalidixic acid, and carbamazepine, ranging from -19% to -79%. PPCPs mainly existed in dissolved form （≥92%） in both the raw influent and the final effluent. The sludge cake carried a much lower amount of PPCPs （17 g·d^-1） compared with the discharged effluent （402 g·d^-1）. In A^2/O treatment tanks, the anaerobic and anoxic tanks showed good performance for PPCPs removal, and the amount of adsorbed PPCPs was increased. The results reveal that both the dissolved and the adsorbed phases should be considered when assessing the removal capacity of each A^2/O tank.展开更多
Polyethylenimine （PEI）-modified chitosan was prepared and used to remove clofibric acid （CA） from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effect...Polyethylenimine （PEI）-modified chitosan was prepared and used to remove clofibric acid （CA） from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy （SEM） showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg· g^-1 for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg· g^-1 on the porous chitosan. The CA adsorption on the PEI- modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceu- ticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI- modified chitosan has a potential application for the removal of some anionic rnicropollutants from water or wastewater.展开更多
Sludge biochar,a carbonized product of raw sludge,contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding.Sludge biochar also immobilizes innate m...Sludge biochar,a carbonized product of raw sludge,contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding.Sludge biochar also immobilizes innate micropollutants,which is advantageous over conventional sludge disposal methods.To date,numerous strategies have been discovered to improve sludge biochar morphology,but the influential factors,pore tuning mechanisms,and process feasibility remain imprecise.This knowledge gap limits our ability to design a robust sludge-based biochar.Herein,we present state-of-the-art sludge biochar synthesis methods with insight into structural and chemical transformation mechanisms.Roadblocks and novel concepts for improving sludge biochar porous architecture are highlighted.For the first time,sludge biochar properties,adsorption performances,and techno-economic perspectives were compared with commercial activated carbon(AC)to reveal the precise challenges in sludge biochar application.More importantly,sludge biochar role in carbon sequestration is detailed to demonstrate the environmental significance of this technology.Eventually,the review concludes with an overview of prospects and an outlook for developing sludge biochar-based research.展开更多
Homolog and congener profiles of polychlori- nated biphenyls （PCBs）, polychlorinated dibenzo-p- dioxins （PCDDs） and polychlorinated dibenzofurans （PCDFs） in commercial PCBs formulations are useful information fo...Homolog and congener profiles of polychlori- nated biphenyls （PCBs）, polychlorinated dibenzo-p- dioxins （PCDDs） and polychlorinated dibenzofurans （PCDFs） in commercial PCBs formulations are useful information for the source appointment of PCBs contam- ination as well as the risk assessment caused by potential exposure. Dielectric oil （ASKAREL Nr 1740） in an imported transformer found in China was sampled and analyzed by isotope dilution technology using high resolution gas chromatography-high resolution mass spectrometry （HRGC/HRMS）. The detailed homolog and congener profiles of PCBs obtained were compared with those of known Aroclor formulations. High similarity in the homolog profile between the oil sample and Aroclor 1260was found, with the hexachlorinated and hepta- chlorinated biphenyls accounting for more than 80.2% of the total PCBs concentration. Severn indicator PCBs contribute about 30%, while 12 PCB congeners （i.e., # 153, #143, #168, #180, #149, #165, #138, #170, #190, #187, #174, #181） account for more than 50% of the total PCB concentrations. Total concentration ofPCDDs, PCDFs and dioxin-like PCBs （DL-PCBs） was found to be 740 ng TEQ/g, of which 620 ng TEQ/g came from DL-PCBs. The contribution of PCDDs to the total TEQ was neglectable. The concentration of PCDFs homologs follows the order of OCDF 〉 HxCDFs 〉 HpCDFs 〉 PeCDFs 〉 TeCDFs, which is in consistence with the previous study on Aroclor 1260. Three DL-PCBs congeners （i.e., #118, #156, #157） accounted for 77% of the total concentration of DL-PCBs, also they contribute 72% in the TEQ caused by DL-PCBs.展开更多
This study mainly focused on the occurrence of pharmaceutical and personal care products(PPCPs)in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants(WWTPs).The data w...This study mainly focused on the occurrence of pharmaceutical and personal care products(PPCPs)in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants(WWTPs).The data were obtained and calculated from seven PPCPs in dewatered sludge collected from 12WWTPs in two typical cities,Beijing and Shenzhen in China.Four of seven PPCPs,diclofenac acid,carbamazepine,mefenamic acid and N,N-diethyl-m-toluamide were detectable in dewatered sludge from Beijing and Shenzhen with concentration up to 4240,11,060,92 and 219μg/kg respectively.While,the other three compounds,trimethoprim,chloramphenicol and bezafibrate were not detected in collected samples from these two cities.The highest discharge of diclofenac acid and carbamazepine were 1023 g/d and 494 g/d respectively.In addition,the total discharge of these four detected PPCPs from each plant ranged from 5 to 1092 g/d in Beijing and 4e497 g/d in Shenzhen.Thus,PPCP discharge through sludge disposal cannot be neglected,and further research on transfer of PPCPs during sludge disposal onto agriculture land and influence of sludge application is required and essential.展开更多
Pharmaceuticals and personal care products(PPCPs)are emerging environmental contaminants,whose potential risk for the ecological environment has caused wide attention in recent years.In China,quite a large amount of P...Pharmaceuticals and personal care products(PPCPs)are emerging environmental contaminants,whose potential risk for the ecological environment has caused wide attention in recent years.In China,quite a large amount of PPCPs were annually emitted into the environment.Their existence in different matrix has been reported frequently,including river water,sediment and soil.However,the contribution from different sources was seldom reported and still unclear in China.Wastewater treatment plant(WWTP)was usually considered to be the main source to the urban river,but livestock and aquaculture farms were also reported as significant pollution sources of PPCPs due to poor environmental management in China.This study summarized environmental discharges of different PPCPs from various sources and obtained the discharge data through different environment media in Beijing,the statistical source of PPCPs was analyzed in detail.The sources comprised WWTPs,excess sludge,hospital wastewater,municipal untreated wastewater,aquaculture wastewater and landfill leachate.This article helps understand the general situation and the potential risk of PPCPs in Beijing.展开更多
Since the launch of the U.S. National Nanotechnology Initiative （NNI） in 2000, research and development in nanotechnology innovation has come a long way worldwide. Based on the Web of Science database, the total SCI...Since the launch of the U.S. National Nanotechnology Initiative （NNI） in 2000, research and development in nanotechnology innovation has come a long way worldwide. Based on the Web of Science database, the total SCI- indexed papers surged from 971 in 2000 to 13, 546 in 2014, and the momentum remains strong. One of the most active and productive research fields has been environmental applications and implications of nanomaterials and nanotechnologies. Environmental nanotechnologies have shown great potential to fundamentally change the conventional practices in environmental cleanup. While the development of innovative cleanup technologies continues to evolve, our understanding of the environmental implications/impacts associated with the booming applications of nanotechnologies in various fields has also deepened. The objectives of this special issue were to： 1） promote exchanges of ideas and information on the latest development of environmental nanotechnologies, 2） facilitate development of more cost-effective and ＂greener＂ cleanup technologies based on innovative nanomaterials and nanotechnologies, 3） address limitation and potential environmental impacts of nanotechnologies and nanomaterials, and 4） identify major knowledge gaps and research directions.展开更多
Three adsorbents including TiO_(2),Ti-Ce,and Ti-La hybrid oxides were prepared to remove fluoride from aqueous solution.The Ti-Ce and Ti-La hybrid adsorbents obtained by the hydrolysis-precipitation method had much hi...Three adsorbents including TiO_(2),Ti-Ce,and Ti-La hybrid oxides were prepared to remove fluoride from aqueous solution.The Ti-Ce and Ti-La hybrid adsorbents obtained by the hydrolysis-precipitation method had much higher sorption capacity for fluoride than the TiO_(2) adsorbent prepared through hydrolysis.Rare earth(Ce and La)oxides and TiO_(2) exhibited a synergistic effect in the hybrid adsorbents for fluoride sorption.The sorption equilibrium of fluoride on the three adsorbents was achieved within 4 h,and the pseudo-second-order model described the sorption kinetics well.The sorption isotherms fitted the Langmuir model well,and the adsorption capacities of fluoride on the Ti-Ce and Ti-La adsorbents were about 9.6 and 15.1 mg·g^(-1),respectively,at the equilibrium fluoride concentration of 1.0 mg·L^(-1),much higher than the 1.7 mg·g^(-1) on the TiO_(2).The sorption capacities of fluoride on the three adsorbents decreased significantly when the solution pH increased from 3 to 9.5.The electrostatic interaction played an important role in fluoride removal by the three adsorbents,and Fourier transform infrared(FTIR)analysis indicated that the hydroxyl groups on the adsorbent surface were involved in fluoride adsorption.展开更多
Ozonation has been proved to be a promising approach for eliminating emerging pollutants in wastewater.In previous studies,emerging pollutants including diverse pharmaceuticals were found to exhibit significantly diff...Ozonation has been proved to be a promising approach for eliminating emerging pollutants in wastewater.In previous studies,emerging pollutants including diverse pharmaceuticals were found to exhibit significantly different ozonation reactivity.However,how the structural differences of emerging pollutants determine ozonation reactivity and mechanisms are still ambiguous.In this work,ozonation of dimethylaminophenazone(DMP)and acetylaminophenazone(AAA)with the same parent structure of phenazone but different substitution groups was investigated,in order to probe influencing mechanisms of structural differences on ozonation reactivity.Results show that DMP reacts with ozone and HOalmost 2 and 1 order of magnitude faster than AAA,respectively.At pH 8,HO· accelerates ozonation of DMP,but decreases ozonation of AAA.Competition simultaneously decreases degradation rate of the two phenazones,but effects on AAA are more significant than that on DMP.According to theoretical calculation results,differences in ozonation reactivity and mechanisms of the two phenazones can be mainly attributed to different substitution groups.The dimethylamino group in the structure of DMP increases the ozonation reactivity of phenazone by increasing reaction orbital energies and altering reaction sites,while the acetylamino group in the structure of AAA decreases the reaction orbital energy and therefore lowers the reactivity.展开更多
基金supported by the National Science Fund for Distinguished Young Scholars(No. 50625823)the Program of Research on Key Technology of Environmental Pollution Control and Quality Improvement(No. 2007DFC90170)
文摘Bisphenol A （BPA） is of global concern due to its disruption of endocrine systems and ubiquity in the aquatic environment. It is important, therefore, that efforts are made to remove it from the aqueous phase. A novel adsorbent, mesoporous carbon CMK-3, prepared from hexagonal SBA- 15 mesoporous silica was studied for BPA removal from aqueous phase, and compared with conventional powdered activated carbon （PAC）. Characterization of CMK-3 by transmission electron microscopy （TEM）, X-ray diffraction, and nitrogen adsorption indicated that prepared CMK-3 had an ordered mesoporous structure with a high specific surface area of 920 m^2/g and a pore-size of about 4.9 nm. The adsorption of BPA on CMK-3 followed a pseudo second-order kinetic model. The kinetic constant was 0.00049 g/（mg.min）, much higher than the adsorption of BPA on PAC. The adsorption isotherm fitted slightly better with the Freundlich model than the Langmuir model, and adsorption capacity decreased as temperature increased from 10 to 40℃. No significant influence of pH on adsorption was observed at pH 3 to 9; however, adsorption capacity decreased dramatically from pH 9 to 13.
基金supported by the National Natural Science Foundation of China (No.21307036)the National High-Tech Research and Development Program of China (No.2013AA062705)the National Key Scientific and Technological Project for Water Pollution Control and Management (Nos.2012ZX07206-002,2012ZX07206-003)
文摘The 6：2 FTS was the substitute for perfluorooctane sulfonate（PFOS） in the chrome plating industry in Japan. Electrochemical oxidation of 6：2 FTS was investigated in this study. The degradabilities of PFOS and 6：2 FTS were tested on the Ti/SnO2–Sb2O5–Bi2O3anode. The effects of current density,potential,and supporting electrolyte on the degradation of 6：2 FTS were evaluated. Experimental results showed that 6：2 FTS was more easily degraded than PFOS on the Ti/SnO2–Sb2O5–Bi2O3anode. At a low current density of 1.42 mA/cm2,6：2 FTS was not degraded on Ti/SnO2–Sb2O5–Bi2O3,while the degradation ratio increased when the current density ranged from 4.25 to 6.80 mA/cm2. The degradation of 6：2 FTS at current density of 6.80 mA/cm2 followed pseudo first-order kinetics with the rate constant of 0.074 hr-1. The anodic potential played an important role in the degradation of 6：2 FTS,and the pseudo first-order rate constants increased with the potential. The surface of Ti/SnO2–Sb2O5–Bi2O3was contaminated after electrolysis at constant potential of 3 V,while the fouling phenomenon was not observed at 5 V. The fouled anode could be regenerated by incinerating at 600°C. The intermediates detected by ultra-performance liquid chromatography coupled with a triple-stage quadrupole mass spectrometer（UPLC–MS/MS） were shorter chain perfluorocarboxylic acids. The 6：2 FTS was first attacked by hydroxyl radical,and then formed perfluorinated carboxylates,which decarboxylated and removed CF2 units to yield shorter-chain perfluorocarboxylic acids.
基金supported by the National Key Research and Development Program of China(No.2022YFC3203703)the Shuimu Tsinghua Scholar Program(China)(No.2024SM277)。
文摘Highly persistent per-and polyfluorinated alkyl substances(PFAS)have been extensively used worldwide for decades and are now ubiquitous in the ecosystem.To combat problems related to PFAS accumulation in the environment and their intrusion into the human body,PFAS adsorption and subsequent breakdown of carbon and fluorine chains are under intense research.Activated carbon(AC)is a widely used adsorbent for PFAS removal from water or wastewater.However,some of its shortcomings include inefficiency in short-chain PFAS removal,a lack of selectivity,overall low adsorption performance,and concerns regarding economic sustainability.Herein,we reviewed the recent innovative carbon-based technologies that aim to address these challenges.In particular,we focus on AC’s topography engineering,defunctionalization(e.g.,removing surface functional groups),hydrophobicity or surface charge modification,water-confining nanopores,and ACnanobubbles synergy.The underlying mechanisms of these novel approaches and their effectiveness in PFAS adsorption are discussed,along with their advancements and limitations.Additionally,the PFAS adsorption and regeneration ability of high-performance ACs are presented and compared.Finally,we address current challenges and offer perspectives on advancing this technology.
文摘Rapidly increasing concentration of CO2 in the atmosphere has drawn more and more attention in recent years, and adsorption has been considered as an effective technology for CO2 capture from the anthropogenic sources. In this paper, the attractive adsorbents including activated carbons and amine-modified materials were mainly reviewed and discussed with particular attention on progress in the adsorbent preparation and C02 adsorption capacity. Carbon materials can be prepared from different precursors including fossil fuels, biomass and resins using the carbonization-activation or only activation process, and activated carbons prepared by KOH activation with high CO2 adsorbed amount were reviewed in the preparation, adsorption capacity as well as the relationship between the pore characteristics and CO2 adsorption. For the amine-modified materials, the physical impregnation and chemical graft of polyethylenimine （PEI） on the different porous materials were introduced in terms of preparation method and adsorption perfor- mance as well as their advantages and disadvantages for CO2 adsorption. In the last section, the issues and prospect of solid adsorbents for CO2 adsorption were summarized, and it is expected that this review will be helpful for the fundamental studies and industrial applications of acti- vated carbons and amine-modified adsorbents for CO2 capture.
文摘The application of appropriate advanced treat- ment process in the municipal wastewater treatment plants （WWTPs） has become an important issue considering the elimination of emerging contaminants, such as pharma- ceutical and personal care products （PPCPs）. In the present study, the removal of 13 PPCPs belonging to different therapeutic classes by the sequential ultraviolet （UV） and ozonation process in a full-scale WWTP in Beijing was investigated over the course of ten months. Most of the target PPCPs were effectively removed, and the median removal efficiencies of individual PPCPs, ranging from -13% to 89%, were dependent on their reaction rate constants with molecular ozone. Noticeable fluctuation in the removal efficiencies of the same PPCPs was observed in different sampling campaigns. Nevertheless, the sequential UV and ozonation process still made a significant contribution to the total elimination of most PPCPs in the full-scale WWTP, by compensating for the poor or fluctuant removal performance of PPCPs by biologic treatment process.
文摘The Stockholm Convention on persistent organic pollutants （POPs） was adopted in 2001. This year is the 10th anniversary of the adoption of the Convention. Until now, 22 chemicals or chemical categories have been listed as POPs in the Stockholm Convention. The POPs Research Center was established in Tsinghua University in the same year when the Convention was adopted. In the last ten years, much work has been done by Chinese researchers to understand the environ- mental risk of POPs in China. This article aims to review the recent research progress of our POPs Research Center and some other Chinese researchers＇ studies in addressing the environmental risk of POPs, including the priority screening and inventory study of POPs, monitoring and modeling of POPs pollution and exposure, and environ- mental risk assessment and modeling of POPs. Although great advances in addressing the environmental risk of POPs have been made in recent years, we are still facing quite a few problems, such as data scarcity and uncertainty in environmental risk assessment of POPs. The study on the effect of POPs mixtures is in its infancy and currently POPs are usually assessed from legal perspective by risk assessment of single chemicals. These problems should be well addressed by further efforts. Further studies should also be taken in future to study environment risk of POPs by considering aspects of coupled dynamics between climate processes and POPs. Such sound scientific, riskbased information can support decision-making aiming to effectively minimize the risk level of POPs.
文摘Effective recovery of high-value heavy metals from electroplating wastewater is of great significance,but recovering nickel ions from real electroplating wastewater as nickel sheet has not been reported.In this study,the pilot-scale fixed-bed resin adsorption was conducted to recover Ni(Ⅱ)ions from real nickel plating wastewater,and then the concentrated Ni(Ⅱ)ions in the regenerated solution were reduced to nickel sheet via electrodeposition.A commercial cation-exchange resin was selected and the optimal resin adsorption and regeneration conditions were investigated.The resin exhibited an adsorption capacity of 63 mg/g for Ni(Ⅱ)ions,and the average amount of treated water was 84.6 bed volumes(BV)in the pilot-scale experiments.After the adsorption by two ion-exchange resin columns in series and one chelating resin column,the concentrations of Ni(Ⅱ)in the treated wastewater were below 0.1 mg/L.After the regeneration of the spent resin using 3 BVof 4%(w/w)HC1 solution,1.5 BV of concentrated neutral nickel solution(>30 g/L)was obtained and used in the subsequent electrodeposition process.Using the aeration method,alkali and water required in resin activation process were greatly reduced to 2 BV and 3 BV,respectively.Under the optimal electrodeposition conditions,95.6%of Ni(Ⅱ)in desorption eluent could be recovered as the elemental nickel on the cathode,llie total treatment cost for the resin adsorption and regeneration as well as the electrodeposition was calculated.
基金This work was supported by the National Natural Science Foundation of China(Grant No.50608045)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution(Grant No.08Z04ESPCT)the National Outstanding Youth Foundation of China(Grant No.50625823).
文摘Perfluorooctane sulfonate(PFOS),as a potential persistent organic pollutant,has been widely detected in water environments,and has become a great concern in recent years.PFOS is very stable and difficult to decompose using conventional techniques.Sorption may be an attractive method to remove it from water.In this study,the molecularly imprinted polymer(MIP)adsorbents were prepared through the polymerization of 4-vinylpyridine under different preparation conditions in order to remove perfluorooctane sulfonate(PFOS)from water.The MIP adsorbents using perfluorooctanoic acid(PFOA)as the template had good imprinting effects and could selectively remove PFOS from aqueous solution.The sorption behaviors including sorption kinetics,isotherms,and effect of pH,salt,and competitive anions were investigated.Experimental results showed that the sorption of PFOS on the MIP adsorbents was very fast,pHdependent,and highly selective.The achieved fast sorption equilibrium within 1 h was attributed to the surface sorption on the fine adsorbents.The sorption isotherms showed that the sorption selectivity of PFOS on the MIP adsorbents decreased at high PFOS concentrations,which may be due to the double-layer sorption and the formation of PFOS micelles on the sorbent surface.The sorption of PFOS on the MIP adsorbents was mainly dominated by the electrostatic interaction between the protonated vinylpyridine on the adsorbent surface and the anionic PFOS.The prepared MIP adsorbents can potentially be applied in water and wastewater treatment for selective removal of PFOS.
基金the Major Science and Technology Program for Water Pollution Control and Treatment in China(No.2017ZX07202006)Program for Changjiang Scholars and Innovative Research Team in University,and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant(No.734522).
文摘This review paper summarizes the occurrence,removal and ecological risk of contaminants of emerging concern(CEC)reported in landfill leachate in China since 1996(43 studies in 10 regions).Results show that many more studies are conducted in developed southeastern China than in developing western and northeastern regions in China.Phthalate esters(PAEs,with 15 studies)and pharmaceuticals and personal care products(PPCPs,with 13 studies)are the two most frequently studied CEC classes.Concentrations of nine CECs classes were in a wide range from 0.03(organochlorine pesticides)to approximately 4500 mg/L(alkylphenol polyethoxylates/bisphenol analog).Meanwhile,concentrations of CEC compounds range from below detection limit(e.g.doxycycline)to approximately 4500 mg/L(bisphenol A).Several PAEs(diethyl phthalate,di-n-butyl phthalate,and di(2-ethylhexyl)phthalate)and PPCPs(diclofenac and gemfibrizol)have significant variation between sampling sites.Typically,advanced treatment processes can achieve higher removal efficiencies of CEC compounds from landfill leachate compared with conventional treatment processes.Furthermore,environmental risk assessments of CEC compounds in treated landfill leachate using a risk quotient method show that 2(substituted)polycyclic aromatic hydrocarbons(sPAHs)(benzo(a)anthracene and benzo(b)fluoranthene),2 PPCPs(bezafibrate and sulfapyridine),g-hexachlorocyclohexane,and bisphenol A pose high risk.The importance of monitoring and potential risks of CECs in the leachate to vicinity aquatic environment cross China is addressed.
基金This work was financially supported by the National Natural Science Foundation of China(21577075)Tsinghua University Initiative Scientific Research Program(20131089193)Program for Changjiang Scholars and Innovative Research Team in University(IRT1261).
文摘Pharmaceuticals and personal care products(PPCPs)have received increasing attention.However,their transformation products(TPs)and metabolites,sometimes even with environmental concentration and/or toxicity higher than their parent compounds,received attention far from enough.This study gives useful insight on the occurrence,fate and toxicity of PPCP TPs or metabolites in WWTPs,surface water and even drinking water,highlighting the necessity of studying the PPCP TPs formation,occurrence,toxicity and environment risk,and further evaluating the environmental risk caused by PPCPs comprehensively.
文摘The fate and removal of pharmaceuticals and personal care products （PPCPs） in wastewater treatment plants （WWTPs） has received great attention during the last decade. Numerous data concerning concentrations in the water phase can be found in the literature, however corresponding data from sludge as well as associated mass balance calculations are very limited. In the present study, the adsorbed and dissolved concentrations of 9 PPCPs were investigated in each unit of a WWTP in Beijing, China. Based on the calculation of mass balance, the relative mass distribution and removal efficiency of each target compound was obtained at each process. The amount of PPCPs entering into the WWTP ranged from 12 g·d^-1 to 3848 g·d^-1. Five target compounds （caffeine, chloramphenicol, bezafibrate, clofibric acid, and N,N- diethyl-meta-toluamide） were effectively removed, with rates of 57%-100%. Negative removal efficiencies were obtained for sulpiride, metoprolol, nalidixic acid, and carbamazepine, ranging from -19% to -79%. PPCPs mainly existed in dissolved form （≥92%） in both the raw influent and the final effluent. The sludge cake carried a much lower amount of PPCPs （17 g·d^-1） compared with the discharged effluent （402 g·d^-1）. In A^2/O treatment tanks, the anaerobic and anoxic tanks showed good performance for PPCPs removal, and the amount of adsorbed PPCPs was increased. The results reveal that both the dissolved and the adsorbed phases should be considered when assessing the removal capacity of each A^2/O tank.
基金Acknowledgements This research was supported by the National Natural Science Foundation of China （Grant No. 51078217）, Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution （No. 12L02ESPC）, and the Collaborative Innovation Center for Regional Environmental Quality. Additionally, the analytical work was supported by the Laboratory Fund of Tsinghua University.
文摘Polyethylenimine （PEI）-modified chitosan was prepared and used to remove clofibric acid （CA） from aqueous solution. PEI was chemically grafted on the porous chitosan through a crosslinking reaction, and the effects of PEI concentration and reaction time in the preparation on the adsorption of clofibric acid were optimized. Scanning electron microscopy （SEM） showed that PEI macromolecules were uniformly grafted on the porous chitosan, and the analysis of pore size distribution indicated that more mesopores were formed due to the crosslinking of PEI molecules in the macropores of chitosan. The PEI-modified chitosan had fast adsorption for CA within the initial 5 h, while this adsorbent exhibited an adsorption capacity of 349 mg· g^-1 for CA at pH 5.0 according to the Langmuir fitting, higher than 213 mg· g^-1 on the porous chitosan. The CA adsorption on the PEI- modified chitosan was pH-dependent, and the maximum adsorption was achieved at pH 4.0. Based on the surface charge analysis and comparison of different pharmaceu- ticals adsorption, electrostatic interaction dominated the sorption of CA on the PEI-modified chitosan. The PEI- modified chitosan has a potential application for the removal of some anionic rnicropollutants from water or wastewater.
基金The United Envirotech Water Treatment(Dafeng)Co.,Ltd(project no.04150700723).
文摘Sludge biochar,a carbonized product of raw sludge,contains porous architectures that can act as epicenters for adsorbing external molecules through physical or chemical bonding.Sludge biochar also immobilizes innate micropollutants,which is advantageous over conventional sludge disposal methods.To date,numerous strategies have been discovered to improve sludge biochar morphology,but the influential factors,pore tuning mechanisms,and process feasibility remain imprecise.This knowledge gap limits our ability to design a robust sludge-based biochar.Herein,we present state-of-the-art sludge biochar synthesis methods with insight into structural and chemical transformation mechanisms.Roadblocks and novel concepts for improving sludge biochar porous architecture are highlighted.For the first time,sludge biochar properties,adsorption performances,and techno-economic perspectives were compared with commercial activated carbon(AC)to reveal the precise challenges in sludge biochar application.More importantly,sludge biochar role in carbon sequestration is detailed to demonstrate the environmental significance of this technology.Eventually,the review concludes with an overview of prospects and an outlook for developing sludge biochar-based research.
文摘Homolog and congener profiles of polychlori- nated biphenyls （PCBs）, polychlorinated dibenzo-p- dioxins （PCDDs） and polychlorinated dibenzofurans （PCDFs） in commercial PCBs formulations are useful information for the source appointment of PCBs contam- ination as well as the risk assessment caused by potential exposure. Dielectric oil （ASKAREL Nr 1740） in an imported transformer found in China was sampled and analyzed by isotope dilution technology using high resolution gas chromatography-high resolution mass spectrometry （HRGC/HRMS）. The detailed homolog and congener profiles of PCBs obtained were compared with those of known Aroclor formulations. High similarity in the homolog profile between the oil sample and Aroclor 1260was found, with the hexachlorinated and hepta- chlorinated biphenyls accounting for more than 80.2% of the total PCBs concentration. Severn indicator PCBs contribute about 30%, while 12 PCB congeners （i.e., # 153, #143, #168, #180, #149, #165, #138, #170, #190, #187, #174, #181） account for more than 50% of the total PCB concentrations. Total concentration ofPCDDs, PCDFs and dioxin-like PCBs （DL-PCBs） was found to be 740 ng TEQ/g, of which 620 ng TEQ/g came from DL-PCBs. The contribution of PCDDs to the total TEQ was neglectable. The concentration of PCDFs homologs follows the order of OCDF 〉 HxCDFs 〉 HpCDFs 〉 PeCDFs 〉 TeCDFs, which is in consistence with the previous study on Aroclor 1260. Three DL-PCBs congeners （i.e., #118, #156, #157） accounted for 77% of the total concentration of DL-PCBs, also they contribute 72% in the TEQ caused by DL-PCBs.
基金supported by Tsinghua University e Veolia Environment Joint Research Center for Advanced Environment Technology and the Program for Changjiang Scholars and Innovative Research Team in University(IRT1261).
文摘This study mainly focused on the occurrence of pharmaceutical and personal care products(PPCPs)in sewage dewatered sludge and their discharges through sludge disposal from wastewater treatment plants(WWTPs).The data were obtained and calculated from seven PPCPs in dewatered sludge collected from 12WWTPs in two typical cities,Beijing and Shenzhen in China.Four of seven PPCPs,diclofenac acid,carbamazepine,mefenamic acid and N,N-diethyl-m-toluamide were detectable in dewatered sludge from Beijing and Shenzhen with concentration up to 4240,11,060,92 and 219μg/kg respectively.While,the other three compounds,trimethoprim,chloramphenicol and bezafibrate were not detected in collected samples from these two cities.The highest discharge of diclofenac acid and carbamazepine were 1023 g/d and 494 g/d respectively.In addition,the total discharge of these four detected PPCPs from each plant ranged from 5 to 1092 g/d in Beijing and 4e497 g/d in Shenzhen.Thus,PPCP discharge through sludge disposal cannot be neglected,and further research on transfer of PPCPs during sludge disposal onto agriculture land and influence of sludge application is required and essential.
基金This work was financially supported by the National Natural Science Foundation of China(41503073)Tsinghua University Initiative Scientific Research Program,and Program for Changjiang Scholars and Innovative Research Team in University(IRT1261).
文摘Pharmaceuticals and personal care products(PPCPs)are emerging environmental contaminants,whose potential risk for the ecological environment has caused wide attention in recent years.In China,quite a large amount of PPCPs were annually emitted into the environment.Their existence in different matrix has been reported frequently,including river water,sediment and soil.However,the contribution from different sources was seldom reported and still unclear in China.Wastewater treatment plant(WWTP)was usually considered to be the main source to the urban river,but livestock and aquaculture farms were also reported as significant pollution sources of PPCPs due to poor environmental management in China.This study summarized environmental discharges of different PPCPs from various sources and obtained the discharge data through different environment media in Beijing,the statistical source of PPCPs was analyzed in detail.The sources comprised WWTPs,excess sludge,hospital wastewater,municipal untreated wastewater,aquaculture wastewater and landfill leachate.This article helps understand the general situation and the potential risk of PPCPs in Beijing.
文摘Since the launch of the U.S. National Nanotechnology Initiative （NNI） in 2000, research and development in nanotechnology innovation has come a long way worldwide. Based on the Web of Science database, the total SCI- indexed papers surged from 971 in 2000 to 13, 546 in 2014, and the momentum remains strong. One of the most active and productive research fields has been environmental applications and implications of nanomaterials and nanotechnologies. Environmental nanotechnologies have shown great potential to fundamentally change the conventional practices in environmental cleanup. While the development of innovative cleanup technologies continues to evolve, our understanding of the environmental implications/impacts associated with the booming applications of nanotechnologies in various fields has also deepened. The objectives of this special issue were to： 1） promote exchanges of ideas and information on the latest development of environmental nanotechnologies, 2） facilitate development of more cost-effective and ＂greener＂ cleanup technologies based on innovative nanomaterials and nanotechnologies, 3） address limitation and potential environmental impacts of nanotechnologies and nanomaterials, and 4） identify major knowledge gaps and research directions.
文摘Three adsorbents including TiO_(2),Ti-Ce,and Ti-La hybrid oxides were prepared to remove fluoride from aqueous solution.The Ti-Ce and Ti-La hybrid adsorbents obtained by the hydrolysis-precipitation method had much higher sorption capacity for fluoride than the TiO_(2) adsorbent prepared through hydrolysis.Rare earth(Ce and La)oxides and TiO_(2) exhibited a synergistic effect in the hybrid adsorbents for fluoride sorption.The sorption equilibrium of fluoride on the three adsorbents was achieved within 4 h,and the pseudo-second-order model described the sorption kinetics well.The sorption isotherms fitted the Langmuir model well,and the adsorption capacities of fluoride on the Ti-Ce and Ti-La adsorbents were about 9.6 and 15.1 mg·g^(-1),respectively,at the equilibrium fluoride concentration of 1.0 mg·L^(-1),much higher than the 1.7 mg·g^(-1) on the TiO_(2).The sorption capacities of fluoride on the three adsorbents decreased significantly when the solution pH increased from 3 to 9.5.The electrostatic interaction played an important role in fluoride removal by the three adsorbents,and Fourier transform infrared(FTIR)analysis indicated that the hydroxyl groups on the adsorbent surface were involved in fluoride adsorption.
基金supported by the National High Technology Research and Development of China(No.2013AA06A305)Program for Changjiang Scholars and Innovative Research Team in University,China Postdoctoral Science Foundation(2013T60128)Hundreds Talents Program of Chinese Academy of Sciences.
文摘Ozonation has been proved to be a promising approach for eliminating emerging pollutants in wastewater.In previous studies,emerging pollutants including diverse pharmaceuticals were found to exhibit significantly different ozonation reactivity.However,how the structural differences of emerging pollutants determine ozonation reactivity and mechanisms are still ambiguous.In this work,ozonation of dimethylaminophenazone(DMP)and acetylaminophenazone(AAA)with the same parent structure of phenazone but different substitution groups was investigated,in order to probe influencing mechanisms of structural differences on ozonation reactivity.Results show that DMP reacts with ozone and HOalmost 2 and 1 order of magnitude faster than AAA,respectively.At pH 8,HO· accelerates ozonation of DMP,but decreases ozonation of AAA.Competition simultaneously decreases degradation rate of the two phenazones,but effects on AAA are more significant than that on DMP.According to theoretical calculation results,differences in ozonation reactivity and mechanisms of the two phenazones can be mainly attributed to different substitution groups.The dimethylamino group in the structure of DMP increases the ozonation reactivity of phenazone by increasing reaction orbital energies and altering reaction sites,while the acetylamino group in the structure of AAA decreases the reaction orbital energy and therefore lowers the reactivity.
