三聚磷酸铝对水中氨氮的吸附动力学

为研究三聚磷酸铝对铵离子（NH4+）的吸附动力学，通过单因素实验、正交实验研究了铵离子初始质量浓度、溶液pH、三聚磷酸铝用量、吸附温度和吸附时间5个因素对溶液中铵离子去除率的影响。各因素由大到小的影响顺序：三聚磷酸铝用量、吸附温度、铵离子初始质量浓度、吸附时间、溶液pH。最佳吸附条件：铵离子初始质量浓度为50 mg/L，溶液pH为4，吸附剂用量为1.5 g，吸附温度为313 K，吸附时间为70 min。在298 K时，三聚磷酸铝对铵离子的吸附符合三级反应动力学特征，其吸附机理是三聚磷酸铝中的质子氢与其表面吸附的铵离子发生了离子交换。

Adsorption kinetics of aluminum tripolyphosphate to ammonia nitrogen in water

Both single factor and orthogonal experiments were used to explore the effect of the 5 factors，such as initial concen-tration of ammonium ion，pH，dosage of the aluminum tripolyphosphate，adsorption temperature，and time on the removal of ammonium ions.The best adsorption conditions were obtained，and adsorption kinetics of NH4+ on aluminum tripolyphosphate was also studied.The experimental results showed that the main influencing factors were in the order as follows：dosage of aluminum tripolyphosphate，temperature，initial concentration of ammonium ion，absorption time，pH.The optimum concentra-ions for adsorption of ammonium ions by aluminum tripolyphosphate in the solution were as follows：the initial concentration of ammonium ion was 50 mg/L，pH=4，the adsorbent dosage was 1.5 g，the adsorption temperature was 313 K，and the adsorption time was 70 min.The adsorption kinetics for ammonium by aluminum tripolyphosphate was in accordance with a third order reaction process under 298 K.The adsorption mechanism of aluminum dihydrogen tripolyphosphate for ammonium ions was discussed at the same time，which indicated that the main forms of NH4+ adsorption were surface adsorption and ion exchange with proton hydrogen in aluminum tripolyphosphate.