高分子絮凝剂DT(PEI-PAM)的优化制备及其除Cu(Ⅱ)性能与机理  

Optimized preparation of dithiocarboxylated polyethyleneiminepolyacrylamide and its Cu(Ⅱ)removal performance and mechanism

作　　者：桑芳娟 王刚[1] 王雪 杨晓敏 SANG Fangjuan;WANG Gang;WANG Xue;YANG Xiaomin(School of Environmental and Municipal Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学环境与市政工程学院,甘肃兰州730070

出　　处：《工业水处理》2024年第12期67-76,共10页Industrial Water Treatment

基　　金：国家自然科学基金项目(51368030)。

摘　　要：以聚丙烯酰胺(PAM)、氢氧化钠(NaOH)、次氯酸钠(NaClO)、二硫化碳(CS2)为原料,制备了二硫代羧基化聚乙烯亚胺-聚丙烯酰胺〔DT(PEI-PAM)〕。以DT(PEI-PAM)对水样中Cu(Ⅱ)的去除率为考察目标,采用正交实验法确定出DT(PEI-PAM)的最佳制备条件;利用絮凝实验研究了DT(PEI-PAM)对Cu(Ⅱ)的去除性能;通过表征手段探究了DT(PEI-PAM)的制备机理及其除Cu(Ⅱ)机理。结果表明,以PAM质量分数为1%、n(PAM)∶n(NaClO)∶n(NaOH)为1∶1∶2、反应温度为30℃、反应时间为120 min、反应介质pH为6.5的最佳条件制备出中间产物聚乙烯亚胺(PEI);再以PEI、CS_(2)、NaOH质量浓度比为1∶2∶3、预反应温度为25℃、预反应时间为40 min、主反应温度为60℃,主反应时间为120 min的最佳条件制备出最终产物DT(PEI-PAM)。DT(PEI-PAM)对含Cu(Ⅱ)水样〔Cu(Ⅱ)初始质量浓度25 mg/L、pH 6.0〕中Cu(Ⅱ)的最高去除率为96.15%。红外表征和能谱分析的结果表明,DT(PEI-PAM)制备过程中成功引入了二硫代羧基,DT(PEI-PAM)对Cu(Ⅱ)的去除机理主要为氧化还原作用和螯合沉淀作用,絮凝作用机理主要为吸附架桥作用,并辅以网捕卷扫作用。Dithiocarboxylated polyethyleneimine-polyacrylamide〔DT(PEI-PAM)〕was prepared by using polyacrylamide(PAM),sodium hydroxide(NaOH),sodium hypochlorite(NaClO),and carbon disulfide(CS2)as raw materials.The Cu(Ⅱ)removal in water samples by DT(PEI-PAM)was investigated as the target,and the optimal preparation conditions of DT(PEI-PAM)were determined by orthogonal experiments.The removal performance of DT(PEI-PAM)for Cu(Ⅱ)was investigated by using flocculation experiments,and the preparation mechanism and the removal mechanism for Cu(Ⅱ)with DT(PEI-PAM)were investigated by characterization means.The results showed that the intermediate polyethylenimide(PEI)was prepared under the optimal conditions as 1% of PAM concentration,1:1:2 of n(PAM):n(NaClO):n(NaOH),30℃ of reaction temperature,120 min of reaction time,and 6.5 of pH in reaction medium.The final product DT(PEI-PAM)was prepared under the optimal conditions as 1:2:3 of reactant mass concentration ratio for PEI:CS_(2):NaOH,25℃ of pre-reaction temperature,40 min of pre-reaction time,60℃ of main reaction temperature,and 120 min of main reaction time.The highest removal rate of Cu(Ⅱ)by DT(PEI-PAM)was 96.15% in water sample〔25 mg/L of Cu(Ⅱ)and pH 6.0〕.The infrared characterization and energy spectrum analysis showed that the dithiocarboxyl groups were successfully introduced in DT(PEI-PAM).The mechanism of DT(PEI-PAM)for Cu(Ⅱ)removal was mainly oxidation reduction and chelation precipitation,and the flocculation mechanism was mainly adsorption bridging and net sweep action.

关 键 词：聚丙烯酰胺 二硫代羧基 含铜废水 絮凝 

分 类 号：X703.1[环境科学与工程—环境工程]