两性高分子螯合絮凝剂和氯化钙对羟基亚乙基二膦酸预镀铜废水的去除性能

Removal performance of amphoteric chelating polymer flocculant and calcium chloride towards hydroxyethylidenediphosphonic acid copper plating wastewater

以羟基亚乙基二膦酸(HEDP)预镀铜废水为处理对象,考察两性高分子螯合絮凝剂(ACPF)和CaCl2对其处理效果.结果表明,单独使用ACPF或CaCl2,用量大,残余Cu2+和COD浓度均不能达到电镀污染物排放标准(GB21900—2008);将ACPF和CaCl2配合使用,Ca2+可与HEDP螯合生成HEDP—Ca沉淀,促进ACPF与Cu2+螯合;且Ca2+还可与废水中的酒石酸根离子形成溶解度很小的结晶,促进絮体的形成和沉降.因此,处理药剂的用量明显降低,Cu2+和COD残余浓度均能达标.适宜的处理条件为:弱碱或碱性条件下,ACPF投加量为3.0 g.L-1,CaCl2投加量为2.0 g.L-1,Cu2+和COD的去除率分别达99.74%和97.5%,残余浓度分别为0.335和25.27 mg.L-1.

The removal perfermance of amphoteric chelating polymer flocculant（ACPF） and calcium chloride towards hydroxyethylidenediphosphonic acid（HEDP） copper plating wastewater was studied in the paper.When using ACPF or CaCl2 as the treatment agent alone,their dosages are large,and the residue concentrations of Cu2＋ and COD can not meet the Effluent Standard of Pollutants for Electroplating（GB21900—2008）.When ACPF is used together with CaCl2,Ca2＋ can chelate with HEDP to form HEDP-Ca precipitates,promoting the chelation of ACPF with Cu2＋;moreover,Ca2＋ can also combine with tartrate ions in the wastewater to form a crystal with very little solubility,promoting the formation and sedimentation of flocs.Therefore,the dosages of ACPF and CaCl2 can obviously decrease and the residual concentrations of Cu2＋ and COD can meet the effluent standard.According to the results,weak alkali or alkaline conditions,associated the dosages of ACPF 3.0 g · L-1 and CaCl2 2.0 g · L-1 are the suitable treatment conditions,the removal rates of Cu2＋ and COD are 99.74% and 97.5%,and their residual concentrations are 0.335 mg · L-1and 25.27 mg · L-1,respectively.