High residual concentration of arsenic and fluoride is a tricky problem to be solved in the process of reinjection after geothermal water utilization.We develop a method to simultaneously remove As(V)and F-from geothe...High residual concentration of arsenic and fluoride is a tricky problem to be solved in the process of reinjection after geothermal water utilization.We develop a method to simultaneously remove As(V)and F-from geothermal water using magnetic Fe_(3)O_(4)@MgO adsorbent,fabricated via a one-step method.The effects of pH,contact time,adsorbent dose and temperature on the removal efficiency were investigated systematically.The results show that the Fe_(3)O_(4)@MgO composite has a wide range of pH(2-11),ultrafast removal dynamics(As(V):2 min;F-:30 min),and high removal efficiency(As(V):99.9%;F-:96.6%).The adsorption kinetics follows the pseudo-secondorder kinetics model,and the adsorption isotherm model fits Freundlich.The adsorption capacity of As(V)and F-can reach 123 and 98.4 mg/g,respectively.The exchange of As(V)and F-with Mg-hydroxyl groups hydrolysis by MgO was determined the adsorption mechanism.The Fe_(3)O_(4)@MgO adsorbent was capable of achieving the adsorption efficiency as high as 99.9%for As(V)and 97.3%for F-in real geothermal water,respectively.Hence,the proposed Fe_(3)O_(4)@MgO composite exhibited as an excellent adsorbent for the remediation of As-and F-contaminated geothermal water.展开更多
基金funded by the Second Comprehensive Scientific Investigation Project of Qinghai-Tibet Plateau(No.2019QZKK0603)the National Natural Science Foundation of China(No.22066022)+2 种基金Science and Technology Plan Projects of Tibet Autonomous Region(No.ZYYD2022000255)Key Projects of“Science and Technology Help Economy 2020”(No.SQ2020YFF0423891)Key Projects of Solid Waste Recycling(No.2019YFC1904103-04)。
文摘High residual concentration of arsenic and fluoride is a tricky problem to be solved in the process of reinjection after geothermal water utilization.We develop a method to simultaneously remove As(V)and F-from geothermal water using magnetic Fe_(3)O_(4)@MgO adsorbent,fabricated via a one-step method.The effects of pH,contact time,adsorbent dose and temperature on the removal efficiency were investigated systematically.The results show that the Fe_(3)O_(4)@MgO composite has a wide range of pH(2-11),ultrafast removal dynamics(As(V):2 min;F-:30 min),and high removal efficiency(As(V):99.9%;F-:96.6%).The adsorption kinetics follows the pseudo-secondorder kinetics model,and the adsorption isotherm model fits Freundlich.The adsorption capacity of As(V)and F-can reach 123 and 98.4 mg/g,respectively.The exchange of As(V)and F-with Mg-hydroxyl groups hydrolysis by MgO was determined the adsorption mechanism.The Fe_(3)O_(4)@MgO adsorbent was capable of achieving the adsorption efficiency as high as 99.9%for As(V)and 97.3%for F-in real geothermal water,respectively.Hence,the proposed Fe_(3)O_(4)@MgO composite exhibited as an excellent adsorbent for the remediation of As-and F-contaminated geothermal water.
