改性海泡石吸附低浓度Ni(Ⅱ)-CA的研究

Study on the adsorption of low concentration Ni(Ⅱ)-CA in electroplating plant wastewater by modified sepiolite

利用3-氨丙基三乙氧基硅烷对海泡石进行改性,用于吸附柠檬酸络合镍(Ni(Ⅱ)-CA)废水,考察了初始pH、吸附剂用量、吸附时间及初始浓度对柠檬酸镍吸附性能的影响,并结合吸附动力学和等温吸附模型对其分析。结果表明,Ni(Ⅱ)-CA浓度为5 mg/L,加入12 g/L吸附剂,pH为6时,室温下反应40 min左右达到平衡,改性海泡石对柠檬酸镍的去除率与吸附量分别为96. 24%和0. 401 mg/g。经过改性后的海泡石吸附能力有较大提高,最大吸附量从0. 619 mg/g提升至1. 116 mg/g,提高了80%。准二级动力学模型和Langmuir等温吸附模型能较好地描述海泡石和改性海泡石对柠檬酸镍的吸附过程。

3-Aminopropyltriethoxysilane(APTES)modified sepiolite was prepared as the adsorbent for removal of Ni(Ⅱ)-CA in the electroplating plant wastewater.The effects of initial concentration and adsorption time,adsorption dose,initial pH in the process of modification on the adsorbing capacity for Ni(Ⅱ)-CA by using modified sepiolite have been investigated,and combined with the dynamic adsorption and its analysis adsorption isotherm model.The removal efficiency and adsorption capacity of Ni(Ⅱ)-CA by APTES-SEP could reach 96.24%and 0.401 mg/g,respectively,when the initial concentration was 5 mg/L and the adsorption dose was 12 g/L at 40 min and room temperature.After amino modification,the adsorption capacity of sepiolite was greatly improved,the maximum adsorption capacity increased from 0.619 mg/g to 1.116 mg/g,and increased by 80%.The adsorption of Ni(Ⅱ)-CA onto sepiolite and modified sepiolite could be well described by Langmuir adsorption isotherm equation and pseudo-second-order model.