Mechanism of controlling dissolved residual aluminum in simultaneous addition of iron and aluminum salt coagulants
LI Mengzhuo1,, CHENG Jixia1, GU Junnong2, LI Yuxian2, ZOU Fang2, YAN Mingquan3,, 1.School of Water and Environment, Chang′an University, Xi′an 710054, China 2.Beijing Engineering Research Center for Drinking Water Quality, Beijing Waterworks Group Co. Ltd., Beijing 100012, China 3.Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environmental Science and Engineering, Peking University, Beijing 100871, China
Abstract:The simultaneous addition of iron and aluminum salt coagulants is a common water treatment process in practice. However, due to the complexity of coagulation process and the lack of effective characterizing methods, the internal mechanism of the above process is still unclear. The combination of UV-vis spectroscopy and the non-ideal competitive adsorption model (NICA) is used to quantitatively characterize the properties of the dissolved organic matter (DOM) in the water when iron and aluminum salt coagulants were simultaneously dosed. The results show that the addition of iron salt (FeCl3) could significantly increase the removal efficiency of phenolic functional groups while ensuring the efficiency of water treatment, and could inhibit the formation of complex organic aluminum through competing the complex sites, which led to the significant decrease of the dissolved residual aluminum concentration. The results are of guiding significance for optimizing the coagulation process control. Key words:residual aluminum/ dissolved organic matter (DOM)/ coagulation/ UV-vis spectroscopy/ metal complex.
图1滤池出水水质参数随着FeCl3投加量的变化 Figure1.Changes of water quality parameters in filtered water with the dosage of FeCl3
图4FeCl3投加量对单位数量活性官能团络合的铝、铁浓度的影响 Figure4.Effect of the FeCl3 dosage on the concentrations of complexed aluminum and iron with an active functional group
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1.School of Water and Environment, Chang′an University, Xi′an 710054, China 2.Beijing Engineering Research Center for Drinking Water Quality, Beijing Waterworks Group Co. Ltd., Beijing 100012, China 3.Key Laboratory of Water and Sediment Sciences, Ministry of Education, School of Environmental Science and Engineering, Peking University, Beijing 100871, China Received Date: 2020-05-14 Accepted Date: 2020-06-13 Available Online: 2021-02-22 Keywords:residual aluminum/ dissolved organic matter (DOM)/ coagulation/ UV-vis spectroscopy/ metal complex Abstract:The simultaneous addition of iron and aluminum salt coagulants is a common water treatment process in practice. However, due to the complexity of coagulation process and the lack of effective characterizing methods, the internal mechanism of the above process is still unclear. The combination of UV-vis spectroscopy and the non-ideal competitive adsorption model (NICA) is used to quantitatively characterize the properties of the dissolved organic matter (DOM) in the water when iron and aluminum salt coagulants were simultaneously dosed. The results show that the addition of iron salt (FeCl3) could significantly increase the removal efficiency of phenolic functional groups while ensuring the efficiency of water treatment, and could inhibit the formation of complex organic aluminum through competing the complex sites, which led to the significant decrease of the dissolved residual aluminum concentration. The results are of guiding significance for optimizing the coagulation process control.
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