Abstract:

The silk printing and dyeing wastewater has been treated with amphoteric chitosan as flocculant. The flocculating property of amphoteric chitosan has been compared with that of carboxymethyl chitosan, quaternized chitosan, poly(aluminum chloride) and polyacrylamide, respectively. The effects of the wastewater pH, mass concentration of the flocculant, type of assistant flocculant and mass ratio of assistant flocculant to amphoteric chitosan on the flocculating properties have been studied. The results indicate that the flocculating property of amphoteric chitosan is better than that of carboxymethyl chitosan, quaternized chitosan, poly(aluminum chloride)and polyacrylamide. When its pH is 5.0-6.0 and mass concentration of amphoteric chitosan is 90 mg/L, the COD removal rate of wastewater could be up to 76.8%. Adding the assistant flocculant could help amphoteric chitosan to improve the COD removal rate of wastewater. When m(assistant flocculant) ∶m(flocculant) =40 and the dosage of the coagulant is 2 500-3 000 mg/L, the COD removal rate of the wastewater is above 80%.

Key words: amphoteric chitosan, chemical oxygen demand, flocculant, assistant flocculant, flocculating property

摘要：

以两性壳聚糖为絮凝剂处理了丝绸印染废水，并与羧甲基壳聚糖、壳聚糖季铵盐、聚合氯化铝和聚丙烯酰胺的絮凝性能进行了比较，研究了废水的pH、絮凝剂的质量浓度、助凝剂的类型及其与两性壳聚糖的复配比对其絮凝性能的影响。结果表明，两性壳聚糖的絮凝性能优于羧甲基壳聚糖、壳聚糖季铵盐、聚合氯化铝和聚丙烯酰胺;在pH为5.0～6.0、絮凝剂两性壳聚糖的质量浓度为90mg/L时，废水的COD去除率可达76.8%;助凝剂的加入可提高两性壳聚糖对COD的去除率，在m(助凝剂)∶m(絮凝剂)=40、混凝剂的加入量为2500～3000mg/L时，废水COD的去除率可在80%以上。

关键词: 两性壳聚糖, 化学需氧量, 絮凝剂, 助凝剂, 絮凝性能

CLC Number: 

• TQ314.253

• TD926.5