铁-铝盐混凝剂混合投加工艺控制溶解性残余铝的机理

Mechanism of controlling dissolved residual aluminum in simultaneous addition of iron and aluminum salt coagulants

铁-铝盐混凝剂混合投加是一种常用给水处理工艺。但由于缺乏有效表征手段,对上述工艺的内在机制认识不清。采用紫外-可见光谱法与非理想竞争吸附模型(NICA)相结合的方法,定量表征铁-铝盐凝剂混合投加时水体中溶解性有机物(DOM)特性。结果表明,铁盐(FeCl3)投加能在保证水处理效能的情况下,显著提高酚基类官能团的去除效率,并且通过竞争络合位点抑制络合态有机铝的生成量,使溶解性残余铝浓度显著降低。以上研究结果对优化混凝工艺控制具有指导意义。

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.