不溶性淀粉黄原酸盐聚丙烯酰胺接枝共聚物除铜降浊研究

Removal of copper and turbidity by insoluble starch xanthate acrylamide

分别以含Cu2+模拟废水和电镀废水为对象,研究了不溶性淀粉黄原酸盐聚丙烯酰胺接枝共聚物(ISXA)去除Cu2+和降低浊度的能力。论述了该药剂去除Cu2+和降低浊度的优点和机理,探讨了去除Cu2+的影响因素,如投药量、pH和反应时间。试验表明(1)对于电镀废水,在5.5倍理论投药量、pH为5.0、反应10min的条件下,Cu2+去除率为98.89%;当pH≥7时,含Cu2+残渣稳定;在2mol/L的盐酸和硝酸溶液中浸泡6h含Cu2+残渣,Cu2+回收率为93.08%;(2)对于含Cu2+模拟废水,在4.5倍理论投药量、pH为5.0、反应10min的条件下,Cu2+去除率可达99.14%,除Cu2+和降浊存在协同作用。

Insoluble starch xanthate acrylamide （ISXA） is effective for removing metal ions and turbidity due to properties of its two components： insoluble starch xanthate （for metal removal）and starch-acrylamide graft copolymer for turbidity reduction）. Effects of ISXA dosage, reaction time and treatment pH on removal of copper ions and turbidity of simulated and actual electroplating wastewater samples were investigated; the removal mechanisms were proposed. In treating the simulated sample, 〉99. 14% Cu^2＋ removal was achieved using 4.5 times the theoretical requirement of ISXA and 10 rain of reaction at pH of 5.0. For the actual wastewater sample, 98.89% of Cu^2＋ was removed by treatment employing 5.5 times the theoretical ISXA in 10 rain of reaction at pH of 5.0. The removal of Cu^2＋ and turbidity were enhanced by the presence of the other species. Nitric acid was more effective than HCl for copper recovery; 〉93.08% of Cu^2＋ was recovered by soaking the dry residues in 2 mol/L nitric acid for more than 6 h. Copper in the residue was stable at a neutral pH; very little copper was released after 2 weeks of contact with water of pH≥7.