Slow release of emerging contaminants limits their accessibility from soil to pore water,constraining the treatment efficiency of physio-chemical treatment sites.DC fields mobilize organic contaminants and influence t...Slow release of emerging contaminants limits their accessibility from soil to pore water,constraining the treatment efficiency of physio-chemical treatment sites.DC fields mobilize organic contaminants and influence their interactions with geo-matrices such as zeolites.Poor knowledge,however,exists on the joint application of heating and electrokinetic approaches on perfluorooctanoic acid(PFOA)transport in porous media.Here,we investigated electrokinetic PFOA transport in zeolite-filled percolation columns at varying temperatures.Variations of pseudo-second-order kinetic constants(kPSO)were correlated to the liquid viscosity variations(η)and elctroosmotic flow velocities(vEOF).Applying DC fields and elevated temperature significantly(>37%)decreased PFOA sorption to zeolite.A good correlation betweenη,vEOF,and kPSO was found and used to develop an approach interlinking the three parameters to predict the joint effects of DC fields and temperature on PFOA sorption kinetics.These findings may give rise to future applications for better tailoring PFOA transport in environmental biotechnology.展开更多
Ultrasonic extraction technique was used to extract perflurooctanoic acid (PFOA) and its salts from fluro-paints.The extract was quantified after filtration and concentration by gas chromatography-mass (GC-MS) method ...Ultrasonic extraction technique was used to extract perflurooctanoic acid (PFOA) and its salts from fluro-paints.The extract was quantified after filtration and concentration by gas chromatography-mass (GC-MS) method using perflurodecanoic acid methyl ester as an internal standard.The GC-MS conditions were: HP-Innowax capillary column; oven temperature,50℃(5 min)30℃/min240℃(5 min); splittless mode; injection volume,1μL; negative chemical ion source,reacting gas,CH4,20%; select ion scan mode (SIM);Line range was 1.0-1.0×105 μg/L; the correlation coefficient was 0.999; the low limit of detection (LOD) was 0.1 μg/L.The RSD was 4.24% and 3.58% respectively for low and high concentration of PFOA,and the average recovery was between 86%-111%.展开更多
采用介质阻挡放电等离子对全氟辛酸(PFOA)进行降解研究,考察了PFOA初始浓度、放电峰-峰值电压、溶液初始p H及初始电导率对PFOA降解的影响.结果表明介质阻挡放电等离子对PFOA具有良好的降解效果.在峰-峰值电压为14 k V,初始电导率为50μ...采用介质阻挡放电等离子对全氟辛酸(PFOA)进行降解研究,考察了PFOA初始浓度、放电峰-峰值电压、溶液初始p H及初始电导率对PFOA降解的影响.结果表明介质阻挡放电等离子对PFOA具有良好的降解效果.在峰-峰值电压为14 k V,初始电导率为50μS·cm-1条件下,2h脱氟率可达48.43%.TOC去除符合伪一级反应动力学,速率常数为0.4075 h-1,去除率达53.30%,投加羟基自由基(·OH)捕获剂实验表明:·OH是主要的活性物质,对PFOA脱氟贡献率78.30%.采用UPLC-QTOF/MS对反应产物进行检测,并推测PFOA可能的降解路径:1·OH氧化PFOA进行脱氟反应生成C6F13C(OH)2COOH,经分子内脱H2O生成C6F13COCOOH;2·OH氧化PFOA分子,使羧酸键—COOH断裂,生成醛类C7F13HO,最后两者都经·OH氧化成C6F13COOH,然后按上述过程逐级脱去CF2生成短链全氟羧酸.展开更多
基金supported by the National Natural Science Foundation of China(No.42277011)the fellowship of the China Postdoctoral Science Foundation(Nos.2023T160667 and 2022M713300)。
文摘Slow release of emerging contaminants limits their accessibility from soil to pore water,constraining the treatment efficiency of physio-chemical treatment sites.DC fields mobilize organic contaminants and influence their interactions with geo-matrices such as zeolites.Poor knowledge,however,exists on the joint application of heating and electrokinetic approaches on perfluorooctanoic acid(PFOA)transport in porous media.Here,we investigated electrokinetic PFOA transport in zeolite-filled percolation columns at varying temperatures.Variations of pseudo-second-order kinetic constants(kPSO)were correlated to the liquid viscosity variations(η)and elctroosmotic flow velocities(vEOF).Applying DC fields and elevated temperature significantly(>37%)decreased PFOA sorption to zeolite.A good correlation betweenη,vEOF,and kPSO was found and used to develop an approach interlinking the three parameters to predict the joint effects of DC fields and temperature on PFOA sorption kinetics.These findings may give rise to future applications for better tailoring PFOA transport in environmental biotechnology.
文摘Ultrasonic extraction technique was used to extract perflurooctanoic acid (PFOA) and its salts from fluro-paints.The extract was quantified after filtration and concentration by gas chromatography-mass (GC-MS) method using perflurodecanoic acid methyl ester as an internal standard.The GC-MS conditions were: HP-Innowax capillary column; oven temperature,50℃(5 min)30℃/min240℃(5 min); splittless mode; injection volume,1μL; negative chemical ion source,reacting gas,CH4,20%; select ion scan mode (SIM);Line range was 1.0-1.0×105 μg/L; the correlation coefficient was 0.999; the low limit of detection (LOD) was 0.1 μg/L.The RSD was 4.24% and 3.58% respectively for low and high concentration of PFOA,and the average recovery was between 86%-111%.
文摘采用介质阻挡放电等离子对全氟辛酸(PFOA)进行降解研究,考察了PFOA初始浓度、放电峰-峰值电压、溶液初始p H及初始电导率对PFOA降解的影响.结果表明介质阻挡放电等离子对PFOA具有良好的降解效果.在峰-峰值电压为14 k V,初始电导率为50μS·cm-1条件下,2h脱氟率可达48.43%.TOC去除符合伪一级反应动力学,速率常数为0.4075 h-1,去除率达53.30%,投加羟基自由基(·OH)捕获剂实验表明:·OH是主要的活性物质,对PFOA脱氟贡献率78.30%.采用UPLC-QTOF/MS对反应产物进行检测,并推测PFOA可能的降解路径:1·OH氧化PFOA进行脱氟反应生成C6F13C(OH)2COOH,经分子内脱H2O生成C6F13COCOOH;2·OH氧化PFOA分子,使羧酸键—COOH断裂,生成醛类C7F13HO,最后两者都经·OH氧化成C6F13COOH,然后按上述过程逐级脱去CF2生成短链全氟羧酸.
