淀粉接枝物和聚合硅铝混凝剂处理制浆造纸废水

采用实验室制备的淀粉丙烯酰胺接枝物(GCAS)和聚硅酸硫酸铝(PASS)混凝剂对制浆造纸废水进行处理,考察了pH 值、药剂用量及沉降时间等对COD去除率和透光度的影响,得出了最佳实验条件.实验结果表明:淀粉丙烯酰胺接枝物在pH=2.0左右时处理效果较好,其最佳用量为32 mg/L;聚硅酸硫酸铝在pH=10.0左右时处理效果较好,最佳用量为48 mg/L;采用复合混凝剂时,淀粉丙烯酰胺接枝物和聚硅酸硫酸铝的用量分别为32 mg/L和48 mg/L,pH=8.0～9.0,沉降时间为25 min条件下,COD去除率达85%以上,透光率可达99%.该复合混凝剂既可以有较高COD去除率,又可以避免二次污染,有较好的环保效果.

New method for processing papermaking wastewater by coagulant of starch graft copolymer and polyalminium silicate sulfate

The present paper has studied the influences of pH of wastewater by adding the amount of GCAS, PASS and settling time on the COD removal rate and photic degree with the optimum conditions obtained. As is known, inorganic and organic polymer coagulant has been widely used for treating living water, industrial water and industrial effluent. The results obtained are satisfactory. Industrial process shows that the GCAS and PASS prepared in the laboratory can well be utilized for papermaking wastewater treatment. The results show that the flocculating effects of GCAS on acid wastewater and PASS on basic wastewater are satisfactory, with the optimum amount to be added being 32 mg/L and 48 mg/L respectively. The optimum amount of GCAS and PASS composite coagulant to be added is GCAS=32 mg/L, and PASS=48 mg/L, pH=8.09.0, and the settling time being 25 min. In this condition, the COD removal rate of this papermaking wastewater proves over 85%, and the light transmission rate is 97%98%. GCAS and PASS composite coagulant can improve the COD removal rate without the second pollution.