• 关键词：高分子重金属絮凝剂  含Cu²⁺废水  淀粉  黄原酸  螯合物

• 基金项目：国家自然科学基金资助项目(No.20377020)

• 刁静茹
• 兰州交通大学环境与市政工程学院, 兰州 730070

• 常青
• 兰州交通大学环境与市政工程学院, 兰州 730070

• 王娟
• 兰州交通大学环境与市政工程学院, 兰州 730070

• 摘要：以淀粉-丙烯酰胺接枝共聚物、NaOH、CS₂为原料,在一定条件下合成了一种新型高分子重金属絮凝剂——淀粉基黄原酸酯-丙烯酰胺接枝共聚物.研究了该絮凝剂的除Cu²⁺、去浊机理,并对硫酸铝浓度、初始Cu²⁺浓度、pH值、浊度等影响其除铜及去浊效能的因素作了考察.实验结果表明:(1)该絮凝剂对Cu²⁺有很好的捕集功能,但需要与硫酸铝复配以提高其沉降性能,适合复配使用.Al³⁺与初始Cu²⁺的体积摩尔浓度比值为0.3较为适宜,此时Cu²⁺去除率大于98%;(2)pH值对复配体系的除Cu²⁺、去浊效果影响不大;(3)Cu²⁺和致浊物质共存时,会互相促进彼此的去除.对初始Cu²⁺浓度为25mg·L^-1、浊度为5～300NTU的水样,处理后出水Cu²⁺浓度小于0.5mg·L^-1、浊度小于3NTU.

• Abstract：A novel water-soluble macromolecule heavy metal flocculant SSXA has been prepared by reacting starch-acrylamide graft copolymers with CS₂ in alkaline medium. In preliminary experiments, the flocculation performance of SSXA was evaluated by using wastewater which contains Cu²⁺ or/and turbidity. Some factors(concentration of Al₂(SO₄)₃,initial concentration of Cu²⁺,pH value, turbidity)which affect the removal of Cu²⁺ and turbidity were also studied. The experiments results showed that: (1) SSXA has strong binding effect with Cu²⁺, but one of the major limitations was that the separation of the Cu-SSXA complex precipitate from the aqueous phase was difficult. This problem was solved by the addition of Al₂(SO₄)₃ solution followed by simple settling. The Al₂(SO₄)₃ acted as a co-precipitator. The removal rate of Cu²⁺ depends on the concentration of Cu²⁺,Al³⁺ and xanthate group of the macromolecule, and the optimum Al³⁺ /Cu²⁺ concentration (mg·L^-1) ratio was 0.3. The removal rate of Cu²⁺ reached above 98% after treatment of water sample that had 25 mg·L^-1 of initial Cu²⁺. (2) The pH has little effect on the removal rates of Cu²⁺ and turbidity. The copper binding and flocculating capabilities of the SSXA- Al₂(SO₄)₃ remains the same in the pH rage 3.5～5.0. (3) Some effects such as charge neutralization of Al³⁺(Cu²⁺) as well as flocculation bridging of SSXA contributed to the subsequent precipitation and separation of the Cu-SSXA complex and turbidity-causing substance, and some dissolved Cu²⁺ could be absorbed onto the surface of the flocs and removed together with them. Therefore Cu²⁺ and turbidity-causing substance promoted the removal of each other. For the wastewater which contains 25 mg·L^-1 of Cu²⁺ and 5～300NTU of turbidity, the residual concentration of Cu²⁺ was below 0.5 mg·L^-1 and the turbidity was below 3NTU after such a simple treatment.

• Key words：macromolecule heavy metal flocculant  copper wastewater  starch  xanthate  chelation  flocculation

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