• 关键词：稳定常数  两性高分子螯合絮凝剂  重金属离子  紫外分光光度法  溶出特性

• 基金项目：国家自然科学基金(No.51078141);湖南省科技计划项目(No.2010FJ3030)

• 刘立华
• 湖南科技大学化学化工学院,理论化学与分子模拟省部共建教育部重点实验室,分子构效关系湖南省普通高等学校重点实验室,湘潭 411201

• 周智华
• 湖南科技大学化学化工学院,理论化学与分子模拟省部共建教育部重点实验室,分子构效关系湖南省普通高等学校重点实验室,湘潭 411201

• 吴俊
• 湖南科技大学化学化工学院,理论化学与分子模拟省部共建教育部重点实验室,分子构效关系湖南省普通高等学校重点实验室,湘潭 411201

• 唐安平
• 湖南科技大学化学化工学院,理论化学与分子模拟省部共建教育部重点实验室,分子构效关系湖南省普通高等学校重点实验室,湘潭 411201

• 令玉林
• 湖南科技大学化学化工学院,理论化学与分子模拟省部共建教育部重点实验室,分子构效关系湖南省普通高等学校重点实验室,湘潭 411201

• 摘要：采用紫外分光光度法测定了两性高分子螯合絮凝剂(ACPF)与Cu²⁺、Cd²⁺、Pb²⁺、Ni²⁺形成螯合物的吸收光谱,考察了螯合沉淀物的稳定性,探讨了螯合物的组成,并计算其稳定常数.结果表明,ACPF分别在204、251和285 nm处出现最大吸收峰;ACPF中—CSS^-基团与Cu²⁺、Pb²⁺、Cd²⁺和Ni²⁺等离子均按物质的量比2:1形成稳定螯合物,分别在319、310、313.5和326 nm处出现最大吸收峰,最大吸收峰发生显著红移.ACPF与Cu²⁺、Pb²⁺、Cd²⁺和Ni²⁺形成的螯合物的稳定常数分别为1.37×10¹²、3.26×10¹¹、2.05×10¹¹和3.04×10¹⁰.螯合沉淀物中重金属离子的溶出率随溶出液pH值升高而降低.pH≥5.6时,ACPF-Cu²⁺、ACPF-Ni²⁺、ACPF-Pb²⁺和ACPF-Cd²⁺都很稳定,浸出60 d后溶出液中Cu²⁺、Ni²⁺、Pb²⁺和Cd²⁺浓度都分别低于相应的国家污水综合排放标准(GB8979—1996).

• Abstract：The absorption spectra of the Cu²⁺, Pb²⁺, Cd²⁺ and Ni²⁺ chelates of an amphoteric chelating polymer flocculant (ACPF) were measured via ultraviolet spectrophotometry. The compositions of the chelates were discussed, and their stability constants were calculated. ACPF exhibited three apparent absorption peaks at 204, 251, and 285nm. The —CSS^- group of ACPF reacted with Cu²⁺, Pb²⁺, Cd²⁺, and Ni²⁺ in a molar ratio of 2:1 to form the chelates ACPF-Cu²⁺, ACPF-Ni²⁺, ACPF-Pb²⁺, and ACPF-Cd²⁺, respectively. The maximum absorption peaks of the chelates appeared at 319, 310, 313.5, and 326 nm, respectively. Compared with the absorption peaks of ACPF, the maximum absorption peaks of the chelates showed significant red shifting. The stability constants of ACPF-Cu²⁺, ACPF-Ni²⁺, ACPF-Pb²⁺, and ACPF-Cd²⁺ are 1.37×10¹², 3.26×10¹¹, 2.05×10¹¹, and 3.04×10¹⁰, respectively. The leaching rate of heavy metal ions from the chelating precipitates decreased with increasing pH. ACPF-Cu²⁺, ACPF-Ni²⁺, ACPF-Pb²⁺, and ACPF-Cd²⁺ were all very stable at pH≥5.6. The Cu²⁺, Ni²⁺, Pb²⁺, and Cd²⁺ concentrations in the leach liquors were lower than the corresponding limits specified by the Integrated Wastewater Discharge Standard of China(GB8979—1996).

• Key words：stability constant  amphoteric chelating polymer flocculant  heavy metal ions  ultraviolet spectrophotometric method  leaching-out characteristics

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