Industrial Water Treatment ›› 2024, Vol. 44 ›› Issue (12): 67-76. doi: 10.19965/j.cnki.iwt.2023-1157

• RESEARCH AND EXPERIMENT • Previous Articles     Next Articles

Optimized preparation of dithiocarboxylated polyethyleneimine-polyacrylamide and its Cu(Ⅱ) removal performance and mechanism

Fangjuan SANG(), Gang WANG(), Xue WANG, Xiaomin YANG   

  1. School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
  • Received:2024-10-13 Online:2024-12-20 Published:2024-12-24

高分子絮凝剂DT(PEI-PAM)的优化制备及其除Cu(Ⅱ)性能与机理

桑芳娟(), 王刚(), 王雪, 杨晓敏   

  1. 兰州交通大学环境与市政工程学院,甘肃 兰州 730070
  • 作者简介:

    桑芳娟(1997— ),硕士研究生。E-mail:

    王刚,教授。E-mail:

  • 基金资助:
    国家自然科学基金项目(51368030)

Abstract:

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:CS2: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.

Key words: polyacrylamide, dithiocarboxyl groups, copper-containing wastewater, flocculation

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、CS2、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。

关键词: 聚丙烯酰胺, 二硫代羧基, 含铜废水, 絮凝

CLC Number: