[Objectives]To evaluate the pollution status of phthalate esters(PAEs)in the soil of facility vegetable base in Yangling District of Xianyang City.[Methods]A total of 15 kinds of PAEs in soil samples were detected and...[Objectives]To evaluate the pollution status of phthalate esters(PAEs)in the soil of facility vegetable base in Yangling District of Xianyang City.[Methods]A total of 15 kinds of PAEs in soil samples were detected and analyzed by gas chromatography-mass spectrometry.[Results]A total of 12 kinds of PAEs were detected in analyzed soil samples,with a total content of 53.4-3524.1μg/kg and an average of 602.7μg/kg.Specifically,DEHP,DBP,DIBP,DMEP,BBP and DNOP were the main PAEs pollutants in the soil,with the detection rates of 100%,100%,100%,73.3%,63.3%and 53.3%,and the average content were 286.3,167.3,123.1,157.6,121.3,and 130.5μg/kg,respectively.[Conclusions]Compared with the soil in other regions,the pollution level of PAEs in the soil of facility vegetable base in Yangling District is lower,but such compounds are widespread in the facility vegetable base,and their potential environmental risks should attract close attention.展开更多
Phthalates esters(PAEs) are extensively used as additives for polymers in plastic, particularly in polyvinyl chloride(PVC) and polyethylene terephthalate(PET). These compounds are not part of the polymer chains and ca...Phthalates esters(PAEs) are extensively used as additives for polymers in plastic, particularly in polyvinyl chloride(PVC) and polyethylene terephthalate(PET). These compounds are not part of the polymer chains and can be released easily from products and migrate into beverages and foods that come into direct contact, causing environmental and human health impacts. Simple and rapid detection of such substances is of great significance for ensuring environmental food safety and consumer health. At present, optical sensor and electrochemical sensor detection technologies have been applied to PAEs detection due to their advantages, such as simple, rapid, low cost, high sensitivity, simple operation, portability and high specificity. They can make up for the shortcomings of chromatographic detection technology, such as expensive equipment, cumbersome operation, the need for professional and technical personnel, and difficulty in achieving a large number of sample screening objectives. In this paper, research progress on optical sensors and electrochemical sensors for the detection of phthalates in recent ten years is reviewed and discussed. This is helpful to better understand preparation methods for sensors and their detection mechanisms for phthalates. The review will also be used in developing a more effective trace detection sensor for phthalates.展开更多
Phthalate esters(PAEs)are widely used as main plasticizers in plastic products,agricultural regulators,toys,and other fields.This paper reviewed the research progress on the distribution,sources,and ecological effects...Phthalate esters(PAEs)are widely used as main plasticizers in plastic products,agricultural regulators,toys,and other fields.This paper reviewed the research progress on the distribution,sources,and ecological effects of PAEs.The effects of PAEs on soil microorganisms,animals,plants and soil properties were explored in sequence,providing effective theoretical basis for future research on PAEs.展开更多
As primary degradation products of phthalate esters,phthalate monoesters(MPEs)have been widely detected in various aquatic environments and drawn growing toxicological concerns.Hydrolysis kinetics that is of importanc...As primary degradation products of phthalate esters,phthalate monoesters(MPEs)have been widely detected in various aquatic environments and drawn growing toxicological concerns.Hydrolysis kinetics that is of importance for assessing environmental persistence of chemicals remain elusive for MPEs.Herein,kinetics of base-catalyzed and neutral hydrolysis for 18 MPEs with different leaving groups was investigated by density functional theory calculation.Results indicate that MPEs with leaving groups having p Kaof<10 prefer dissociative transition states.MPEs are more persistent than their parents,and their hydrolysis half-lives were calculated to vary from 3.4 min to 79.2 years(p H=7–9).A quantitative structure-activity relationship model was developed for predicting the hydrolysis kinetics parameters.It was found that p Kaof the leaving groups and electronegativity of the MPEs are key factors determining the hydrolysis kinetics.This work may lay a theoretical foundation for better understanding the chemical process that governs MPE persistence in aquatic environments.展开更多
Microplastics(MPs)and phthalate acid esters(PAEs)co-occur as emerging contaminants of global importance.Their abundance in soil is of increasing concern as plastic-intensive practices continue.Mulching with plastic fi...Microplastics(MPs)and phthalate acid esters(PAEs)co-occur as emerging contaminants of global importance.Their abundance in soil is of increasing concern as plastic-intensive practices continue.Mulching with plastic films,inclusion in fertilizers,composts,sludge application,and wastewater irrigation are all major and common sources of MPs and PAEs in soil.Here,we review studies on the concentration and effects of MPs and PAEs in soil.While there is limited research on the interactions between MPs and PAEs in agroecosystems,there is evidence to suggest they could mutually affect soil ecology and plant growth.Therefore,we propose new research into 1)establishing an efficient,accurate,and simple method to quantify different types of microplastics in soils and plants;2)exploring the behavior and understanding the mechanisms of co-transfer,transformation,and interactions with soil biota(especially in vegetable production systems);3)assessing the risk and consequences of combined and discreet impacts of MPs and PAEs on plants and soil biota,and 4)preventing or reducing the transfer of MPs and PAEs into-and within-the food chain.展开更多
Lipid metabolism play an essential role in occurrence and development of asthma,and it can be disturbed by phthalate esters(PAEs)and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease,...Lipid metabolism play an essential role in occurrence and development of asthma,and it can be disturbed by phthalate esters(PAEs)and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease,the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure,but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the disease.We have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled with mass spectrometry,and its relationships with the dysregulation of lipid metabolism in asthmatic,bronchitic(acute infammation)and healthy(non-infammation)children.Eight PAEs and nine OPFRs congeners were found in the serum of children(1–5 years old)from Shenzhen,and their total median levels were 615.16 ng/m L and 17.06 ng/m L,respectively.Moreover,the serum levels of mono-methyl phthalate(MMP),tri-propyl phosphate(TPP)and tri-n-butyl phosphate(TNBP)were significant higher in asthmatic children than in healthy and bronchitic children as control.Thirty-one characteristic lipids and fatty acids of asthma were screened by machine-learning random forest model based on serum lipidome data,and the alterations of infammatory characteristic lipids and fatty acids including palmitic acids,12,13-Di HODE,14,21-Di HDHA,prostaglandin D2 and Lyso PA(18:2)showed significant correlated with high serum levels of MMP,TPP and TNBP.These results imply PAEs and OPFRs promote the occurrence of childhood asthma via disrupting infammatory lipid and fatty acid metabolism,and provide a novel sight for better understanding the effects of plastic additives on childhood asthma.展开更多
Phthalate esters(PAEs),typical pollutants widely used as plasticizers,are ubiquitous in various indoor and outdoor environments.PAEs exist in both gas and particle phases,posing risks to human health.In the present st...Phthalate esters(PAEs),typical pollutants widely used as plasticizers,are ubiquitous in various indoor and outdoor environments.PAEs exist in both gas and particle phases,posing risks to human health.In the present study,we chose four typical kinds of indoor and outdoor environments with the longest average human residence times to assess the human exposure in Hangzhou,including newly decorated residences,ordinary residences,offices and outdoor air.In order to analyze the pollution levels and characteristics of 15 gasand particle-phase PAEs in indoor and outdoor environments,air and particulate samples were collected simultaneously.The total PAEs concentrations in the four types of environments were 25,396,25,466.8,15,388.8 and 3616.2 ng/m^3,respectively.DEHP and DEP were the most abundant,and DMPP was at the lowest level.Distinct variations in the distributions of indoor/outdoor,gas/particle-phase and different molecular weights of PAEs were observed,showing that indoor environments were the main sources of PAEs pollution.While most PAEs tended to exsit in indoor sites and gas-phase,the high-molecular-weight chemicals tended to exist in the particle-phase and were mainly found in PM2.5.PAEs were more likely adsorbed by small particles,especially for the indoor environments.There existed a good correlation between the particle matter concentrations and the PAEs levels.In addition,neither temperature nor humidity had obvious effects on the distributions of the PAEs concentrations.展开更多
Nano-Fe_(2)O_(3)embedded in montmorillonite particles(Fe-Mt)were prepared to degrade diethyl phthalate(DEP)with citric acid(CA)under xenon light irradiation.Compared to pristine montmorillonite(Na-Mt),the embedding pr...Nano-Fe_(2)O_(3)embedded in montmorillonite particles(Fe-Mt)were prepared to degrade diethyl phthalate(DEP)with citric acid(CA)under xenon light irradiation.Compared to pristine montmorillonite(Na-Mt),the embedding process increased 14.5-fold of iron content and 1.8-fold of specific surface area.The synthesized Fe-Mt have more oxygen vacancies than Fe_(2)O_(3)nanoparticles(nFe_(2)O_(3)),which could induce more reactive oxygen species(ROSs)generation in the presence of CA under xenon lamp irradiation.Fe-Mt with CA enhanced photo-assisted degradation of DEP 2.5 times as compared to nFe_(2)O_(3)with CA.Quenching experiments,electron paramagnetic resonance(EPR)spectroscopy and identification of products confirmed that surface-bound·OH was the main radical to degrade DEP.Common anions(i.e.,NO_(3)-,CO_(3)^(2-),Cl^-)and humic acid could compete·OH with DEP and cause slower degradation of DEP.The removal efficiency of DEP was more than 56%with Fe-Mt after three recycles,and the dissolved Fe concentration from Fe-Mt was below 75μmol/L,indicating Fe-Mt had a good stability as a catalyst.Fe-Mt together with CA appeared to be a promising strategy to remove organic pollutants in surface water,or topsoil under solar irradiation.展开更多
Microplastics(MPs)and plasticizers,such as phthalate esters(PAEs),were frequently detected in municipal wastewater treatment plants(MWTP).Previous research mainly studied the removal of MPs and PAEs in wastewater.Howe...Microplastics(MPs)and plasticizers,such as phthalate esters(PAEs),were frequently detected in municipal wastewater treatment plants(MWTP).Previous research mainly studied the removal of MPs and PAEs in wastewater.However,the occurrence of MPs and PAEs in the sludge was generally ignored.To comprehensively investigate the occurrence and the migration behaviors of MPs and PAEs in MWTP,a series of representative parameters including the number,size,color,shape of MPs,and the concentrations of PAEs in wastewater and sludge were systematically investigated.In this study,the concentrations of MPs in the influent and effluent were 15.46±0.37 and 0.30±0.14 particles/L.The MP removal efficiency of 98.1%was achieved and about 73.8%of MPs were accumulated in the sludge in the MWTP.The numbers of MPs in the sludge before and after digestion were 4.40±0.14 and 0.31±0.01 particles/g(dry sludge),respectively.Fourier Transform Infrared Spectroscopy(ATR FT-IR)analysis showed that the main types of MPs were polyethylene terephthalate(PET),polypropylene(PP),polyethylene(PE),and polystyrene(PS).Six PAEs,including phthalate(DMP),diethyl phthalate(DEP),diisobutyl phthalate(DIBP),ortho dibutyl phthalate(DBP),butyl benzyl phthalate(BBP),and bis(2-ethyl)hexyl phthalate(DEHP),were detected in the MWTP.The concentrations of total PAEs(ΣPAEs)in the influent and effluent were 76.66 and 6.28μg/L,respectively.The concentrations ofΣPAEs in the sludge before and after digestion were 152.64 and 31.70μg/g,respectively.In the process of thermal hydrolysis,the number and size of MPs decreased accompanied by the increase of the plasticizer concentration.展开更多
Six phthalate acid esters(PAEs)priority pollutants[dimethyl phthalate(DMP),diethyl phthalate(DEP),dibutyl phthalate(DBP or DNBP),di-n-octyl phthalate(DNOP),di 2-ethyl hexyl phthalate(DEHP),and butyl benzyl phthalate(B...Six phthalate acid esters(PAEs)priority pollutants[dimethyl phthalate(DMP),diethyl phthalate(DEP),dibutyl phthalate(DBP or DNBP),di-n-octyl phthalate(DNOP),di 2-ethyl hexyl phthalate(DEHP),and butyl benzyl phthalate(BBP)]were opted as the research object.PAE-degrading esterase CarEW(PDB ID:1C7I)isolated from Bacillus subtilis acting as a template and an iterative saturation mutation strategy was adopted to modify key amino acids to attain efficient PAE-degrading esterase substitutes with a reasonable structure constructed by homology modeling method.Present study designed a total of 285 unit-site and multi-site substitutions of PAE-degrading esterase using the homology modeling method.Among them,207 PAE-degrading esterase substitutions,which contained the 6-site PAE-degrading esterase substitute 1C7I-6-9 with 84.21%enhancement intensity of degradation ability revealed better degradability to all the 6 PAEs after modification.Moreover,molecular dynamics simulation based on the Taguchi method reported the optimal external application environment for PAE-degrading esterase substitutes as follows:pH=6,T=35℃,the rhamnolipid concentration was 50 mg/L,the molar ratio of nitrogen to phosphorus(N:P)was 10:1,the concentration of H2O_(2) was 50 mg/L,and the voltage gradient was 1.5 V/cm.The degradation ability of PAE-degrading esterase substitutes was found to be elevated by 13.04%as compared to that of the blank control under the optimal condition.Moreover,11 highly efficient PAE-degrading esterase substitutes with thermal stability were designed.展开更多
基金Supported by Scientific Research Fund Project of Yangling Vocational and Technical College(A2018053)Science and Technology Plan Project of Yangling Agricultural High-tech Industry Demonstration Zone(2018SF-02).
文摘[Objectives]To evaluate the pollution status of phthalate esters(PAEs)in the soil of facility vegetable base in Yangling District of Xianyang City.[Methods]A total of 15 kinds of PAEs in soil samples were detected and analyzed by gas chromatography-mass spectrometry.[Results]A total of 12 kinds of PAEs were detected in analyzed soil samples,with a total content of 53.4-3524.1μg/kg and an average of 602.7μg/kg.Specifically,DEHP,DBP,DIBP,DMEP,BBP and DNOP were the main PAEs pollutants in the soil,with the detection rates of 100%,100%,100%,73.3%,63.3%and 53.3%,and the average content were 286.3,167.3,123.1,157.6,121.3,and 130.5μg/kg,respectively.[Conclusions]Compared with the soil in other regions,the pollution level of PAEs in the soil of facility vegetable base in Yangling District is lower,but such compounds are widespread in the facility vegetable base,and their potential environmental risks should attract close attention.
基金financially supported by the National Natural Science Foundation of China (Nos. 61871180, 61971187, and 61901168)Hunan Provincial Innovation Foundation for Postgraduate (No. CX20211074)Open Funding of State Key Laboratory of Oral Diseases (No. SKLOD2022OF05)。
文摘Phthalates esters(PAEs) are extensively used as additives for polymers in plastic, particularly in polyvinyl chloride(PVC) and polyethylene terephthalate(PET). These compounds are not part of the polymer chains and can be released easily from products and migrate into beverages and foods that come into direct contact, causing environmental and human health impacts. Simple and rapid detection of such substances is of great significance for ensuring environmental food safety and consumer health. At present, optical sensor and electrochemical sensor detection technologies have been applied to PAEs detection due to their advantages, such as simple, rapid, low cost, high sensitivity, simple operation, portability and high specificity. They can make up for the shortcomings of chromatographic detection technology, such as expensive equipment, cumbersome operation, the need for professional and technical personnel, and difficulty in achieving a large number of sample screening objectives. In this paper, research progress on optical sensors and electrochemical sensors for the detection of phthalates in recent ten years is reviewed and discussed. This is helpful to better understand preparation methods for sensors and their detection mechanisms for phthalates. The review will also be used in developing a more effective trace detection sensor for phthalates.
基金Supported by Undergraduate Innovation and Entrepreneurship Training Program (202310580018).
文摘Phthalate esters(PAEs)are widely used as main plasticizers in plastic products,agricultural regulators,toys,and other fields.This paper reviewed the research progress on the distribution,sources,and ecological effects of PAEs.The effects of PAEs on soil microorganisms,animals,plants and soil properties were explored in sequence,providing effective theoretical basis for future research on PAEs.
基金supported by the National Natural Science Foundation of China (No.22136001)the National Key R&D Program of China (No.2022YFC3902100)+2 种基金the Key R&D Program of Hebei Province (No.21374001D)the Supercomputing Center of Dalian University of Technologythe National Supercomputer Center in Tianjin。
文摘As primary degradation products of phthalate esters,phthalate monoesters(MPEs)have been widely detected in various aquatic environments and drawn growing toxicological concerns.Hydrolysis kinetics that is of importance for assessing environmental persistence of chemicals remain elusive for MPEs.Herein,kinetics of base-catalyzed and neutral hydrolysis for 18 MPEs with different leaving groups was investigated by density functional theory calculation.Results indicate that MPEs with leaving groups having p Kaof<10 prefer dissociative transition states.MPEs are more persistent than their parents,and their hydrolysis half-lives were calculated to vary from 3.4 min to 79.2 years(p H=7–9).A quantitative structure-activity relationship model was developed for predicting the hydrolysis kinetics parameters.It was found that p Kaof the leaving groups and electronegativity of the MPEs are key factors determining the hydrolysis kinetics.This work may lay a theoretical foundation for better understanding the chemical process that governs MPE persistence in aquatic environments.
基金This research was funded by the National Key Research and Development Program of China(2016YFD0800204)the Outstanding Youth Fund of Natural Science Foundation of Jiangsu,China(BK20150050)+2 种基金the National Natural Science Foundation of China(41977137,42007145,41977356)the Key Program of Frontier Sciences,Chinese Academy of Sciences(QYZDJ-SSWDQC035)the Natural Science Foundation of Jiangsu,China(BK20201106).
文摘Microplastics(MPs)and phthalate acid esters(PAEs)co-occur as emerging contaminants of global importance.Their abundance in soil is of increasing concern as plastic-intensive practices continue.Mulching with plastic films,inclusion in fertilizers,composts,sludge application,and wastewater irrigation are all major and common sources of MPs and PAEs in soil.Here,we review studies on the concentration and effects of MPs and PAEs in soil.While there is limited research on the interactions between MPs and PAEs in agroecosystems,there is evidence to suggest they could mutually affect soil ecology and plant growth.Therefore,we propose new research into 1)establishing an efficient,accurate,and simple method to quantify different types of microplastics in soils and plants;2)exploring the behavior and understanding the mechanisms of co-transfer,transformation,and interactions with soil biota(especially in vegetable production systems);3)assessing the risk and consequences of combined and discreet impacts of MPs and PAEs on plants and soil biota,and 4)preventing or reducing the transfer of MPs and PAEs into-and within-the food chain.
基金supported by the National Natural Science Foundation of China (Nos.22076197,21707149 and 82127801)the Scientific Instrument Developing Project of the Chinese Academy of Sciences (No.YJKYYQ20200034)+1 种基金Shenzhen Science and Technology Research Funding (Nos.JCYJ20210324115811031 and JCYJ20200109115405930)Guangdong Basic and Applied Basic Research Foundation (No.2020B1515120080)。
文摘Lipid metabolism play an essential role in occurrence and development of asthma,and it can be disturbed by phthalate esters(PAEs)and organophosphate fame retardants(OPFRs).As a chronic infammatory respiratory disease,the occurrence risk of childhood asthma is increased by PAEs and OPFRs exposure,but it remains not entirely clear how PAEs and OPFRs contribute the onset and progress of the disease.We have profiled the serum levels of PAEs and OPFRs congeners by liquid chromatography coupled with mass spectrometry,and its relationships with the dysregulation of lipid metabolism in asthmatic,bronchitic(acute infammation)and healthy(non-infammation)children.Eight PAEs and nine OPFRs congeners were found in the serum of children(1–5 years old)from Shenzhen,and their total median levels were 615.16 ng/m L and 17.06 ng/m L,respectively.Moreover,the serum levels of mono-methyl phthalate(MMP),tri-propyl phosphate(TPP)and tri-n-butyl phosphate(TNBP)were significant higher in asthmatic children than in healthy and bronchitic children as control.Thirty-one characteristic lipids and fatty acids of asthma were screened by machine-learning random forest model based on serum lipidome data,and the alterations of infammatory characteristic lipids and fatty acids including palmitic acids,12,13-Di HODE,14,21-Di HDHA,prostaglandin D2 and Lyso PA(18:2)showed significant correlated with high serum levels of MMP,TPP and TNBP.These results imply PAEs and OPFRs promote the occurrence of childhood asthma via disrupting infammatory lipid and fatty acid metabolism,and provide a novel sight for better understanding the effects of plastic additives on childhood asthma.
基金supported by the National Key R&D Program of China (No. 2016YFC0207103)the National Natural Science Foundation of China (No. 21607127)the Brain Bridge project with Koninklijke Philips N.V. (No. BB3-2016-01)
文摘Phthalate esters(PAEs),typical pollutants widely used as plasticizers,are ubiquitous in various indoor and outdoor environments.PAEs exist in both gas and particle phases,posing risks to human health.In the present study,we chose four typical kinds of indoor and outdoor environments with the longest average human residence times to assess the human exposure in Hangzhou,including newly decorated residences,ordinary residences,offices and outdoor air.In order to analyze the pollution levels and characteristics of 15 gasand particle-phase PAEs in indoor and outdoor environments,air and particulate samples were collected simultaneously.The total PAEs concentrations in the four types of environments were 25,396,25,466.8,15,388.8 and 3616.2 ng/m^3,respectively.DEHP and DEP were the most abundant,and DMPP was at the lowest level.Distinct variations in the distributions of indoor/outdoor,gas/particle-phase and different molecular weights of PAEs were observed,showing that indoor environments were the main sources of PAEs pollution.While most PAEs tended to exsit in indoor sites and gas-phase,the high-molecular-weight chemicals tended to exist in the particle-phase and were mainly found in PM2.5.PAEs were more likely adsorbed by small particles,especially for the indoor environments.There existed a good correlation between the particle matter concentrations and the PAEs levels.In addition,neither temperature nor humidity had obvious effects on the distributions of the PAEs concentrations.
基金funded by the National Key Research and Development Program of China(Nos.2017YFA0207000 and 2018YFC1802000)the National Natural Science Foundation of China(No.41773125)。
文摘Nano-Fe_(2)O_(3)embedded in montmorillonite particles(Fe-Mt)were prepared to degrade diethyl phthalate(DEP)with citric acid(CA)under xenon light irradiation.Compared to pristine montmorillonite(Na-Mt),the embedding process increased 14.5-fold of iron content and 1.8-fold of specific surface area.The synthesized Fe-Mt have more oxygen vacancies than Fe_(2)O_(3)nanoparticles(nFe_(2)O_(3)),which could induce more reactive oxygen species(ROSs)generation in the presence of CA under xenon lamp irradiation.Fe-Mt with CA enhanced photo-assisted degradation of DEP 2.5 times as compared to nFe_(2)O_(3)with CA.Quenching experiments,electron paramagnetic resonance(EPR)spectroscopy and identification of products confirmed that surface-bound·OH was the main radical to degrade DEP.Common anions(i.e.,NO_(3)-,CO_(3)^(2-),Cl^-)and humic acid could compete·OH with DEP and cause slower degradation of DEP.The removal efficiency of DEP was more than 56%with Fe-Mt after three recycles,and the dissolved Fe concentration from Fe-Mt was below 75μmol/L,indicating Fe-Mt had a good stability as a catalyst.Fe-Mt together with CA appeared to be a promising strategy to remove organic pollutants in surface water,or topsoil under solar irradiation.
基金supported by the National Natural Science Foundation of China(Nos.42177051 and 52170021).
文摘Microplastics(MPs)and plasticizers,such as phthalate esters(PAEs),were frequently detected in municipal wastewater treatment plants(MWTP).Previous research mainly studied the removal of MPs and PAEs in wastewater.However,the occurrence of MPs and PAEs in the sludge was generally ignored.To comprehensively investigate the occurrence and the migration behaviors of MPs and PAEs in MWTP,a series of representative parameters including the number,size,color,shape of MPs,and the concentrations of PAEs in wastewater and sludge were systematically investigated.In this study,the concentrations of MPs in the influent and effluent were 15.46±0.37 and 0.30±0.14 particles/L.The MP removal efficiency of 98.1%was achieved and about 73.8%of MPs were accumulated in the sludge in the MWTP.The numbers of MPs in the sludge before and after digestion were 4.40±0.14 and 0.31±0.01 particles/g(dry sludge),respectively.Fourier Transform Infrared Spectroscopy(ATR FT-IR)analysis showed that the main types of MPs were polyethylene terephthalate(PET),polypropylene(PP),polyethylene(PE),and polystyrene(PS).Six PAEs,including phthalate(DMP),diethyl phthalate(DEP),diisobutyl phthalate(DIBP),ortho dibutyl phthalate(DBP),butyl benzyl phthalate(BBP),and bis(2-ethyl)hexyl phthalate(DEHP),were detected in the MWTP.The concentrations of total PAEs(ΣPAEs)in the influent and effluent were 76.66 and 6.28μg/L,respectively.The concentrations ofΣPAEs in the sludge before and after digestion were 152.64 and 31.70μg/g,respectively.In the process of thermal hydrolysis,the number and size of MPs decreased accompanied by the increase of the plasticizer concentration.
文摘Six phthalate acid esters(PAEs)priority pollutants[dimethyl phthalate(DMP),diethyl phthalate(DEP),dibutyl phthalate(DBP or DNBP),di-n-octyl phthalate(DNOP),di 2-ethyl hexyl phthalate(DEHP),and butyl benzyl phthalate(BBP)]were opted as the research object.PAE-degrading esterase CarEW(PDB ID:1C7I)isolated from Bacillus subtilis acting as a template and an iterative saturation mutation strategy was adopted to modify key amino acids to attain efficient PAE-degrading esterase substitutes with a reasonable structure constructed by homology modeling method.Present study designed a total of 285 unit-site and multi-site substitutions of PAE-degrading esterase using the homology modeling method.Among them,207 PAE-degrading esterase substitutions,which contained the 6-site PAE-degrading esterase substitute 1C7I-6-9 with 84.21%enhancement intensity of degradation ability revealed better degradability to all the 6 PAEs after modification.Moreover,molecular dynamics simulation based on the Taguchi method reported the optimal external application environment for PAE-degrading esterase substitutes as follows:pH=6,T=35℃,the rhamnolipid concentration was 50 mg/L,the molar ratio of nitrogen to phosphorus(N:P)was 10:1,the concentration of H2O_(2) was 50 mg/L,and the voltage gradient was 1.5 V/cm.The degradation ability of PAE-degrading esterase substitutes was found to be elevated by 13.04%as compared to that of the blank control under the optimal condition.Moreover,11 highly efficient PAE-degrading esterase substitutes with thermal stability were designed.
