新合成复合絮凝剂HECES絮凝性能研究

Performance of a novel combined flocculant HECES

以无机铝盐和天然高分子玉米淀粉为原料 ,合成一种生态安全型复合高效絮凝剂HECES .结果表明 ,在一定范围里适当提高淀粉 /铝盐比例 ,有利于HECES絮凝性能的提高 ;处理模拟废水时 ,3.0mg·L-1的HECES相当于 4 .5mg·L-1PAC和 1.0mg·L-1PAM复合投加效果 ;对生活污水、市政污水的最佳投加量分别为 8.0mg·L-1和 4 .0mg·L-1,相当于PAC用量的 5 0 %和 4 0 % ,浊度去除率高达 95 %和99% .研究还证实絮凝效果与模拟浊度废水的浓度、供试污水的组成成分有关 ,HECES对高浓度废水处理效果更佳 .HECES在 pH =4 .0～ 9.5范围内絮凝效果最佳 .其生态安全特点体现在投加量少 ,具有较大生态毒性的游离态铝离子残留量低 .

Combined flocculants with higher environmental safty and lower ecological risk are urgently required in the process of water and wastewater treatment. HECES, a kind of flocculants with high effect and high ecological safety was synthesized by natural and biodegradable polysaccharide starch of corn and inorganic aluminium salt. Flocculent performance includes sediment character and turbidity removal rate. The jar test results showed that the flocculent performance of HECES with the dose of 3.0mg·L -1 was prior to the combined adding 4.5 mg·L -1 PAC and 1.0 mg·L -1 PAM in treating kaolin suspensions. The optimal concentration of HECES was 8.0 mg·L -1 and 4.0 mg·L -1 in treating domestic wastewater and municipal effluent respectively, with the comparison to 50% an 40% of PAC, the removal rate of turbidity reached 95% and 99%, respectively. It was also identified that the optimal concentration required to effect flocculation depended on kaolin concentration,and on the character of the wastewater within the range examined. It could be more effective to treat wastewater with higher concentration of HECES. The flocculating performance would be better at pH 4.0～9.5.The superior ecological safety of HECES was due to its lower dosage and its lower concentration of residual activated aluminium.