阳离子高分子絮凝剂处理造纸废水的研究

Study on Treatment of Papermaking Wastewater with Cationic Polymer Flocculant

用丙烯酰胺和聚2-羟基丙基二乙基氯化铵的水溶液聚合制备了一种阳离子型聚季铵盐丙烯酰胺接枝共聚物絮凝剂(PAQD),并将其用于造纸废水的处理,研究了体系pH值、絮凝剂用量和水温对絮凝效果的影响。结果表明,在pH值4～9范围内,PAQD絮凝剂对废水均有很好的处理效果。在常温、pH值7.0、PAQD用量5 mg/L的条件下,SS、COD_(Cr)和色度的去除率分别为91.8%、80.5%和94.1%;温度对COD_(Cr)去除率的影响不大;与常规絮凝剂APAM(阴离子聚丙烯酰胺)、NPAM(非离子聚丙烯酰胺)、PAC(聚合氯化铝)及PFS(聚合硫酸铁)相比,PAQD絮凝剂具有投量少、絮凝沉降速度快、滤饼含水率低、上清液透光性好等特点。

A type of cationic flocculant polyquaternary ammonium acrylamide graft copolymer（PAQD） was prepared from acrylamide and poly-2- hydroxylpropyldiethyl ammonium chloride and was used as flocculant in the treatment of papermaking wastewater. The influence of pH value, flocculant dosage and temperature on flocculation effect was investigated. The results showed that this cationic flocculant had satisfactory results in papermaking wastewater treatment under the pH value ranging from 4 to 9. The removal rate of SS, CODcr and colourity was 91.8%, 80.5% and 94.1% respectively in the condition where temperature was normal, pH value was 7.0 and flocculant dosage was 5mg/L. The temperature had little impact on the removal rate of CODcr In comparison with the conventional flocculants, such as APAM（anionic polyacrylamide）, NPAM（nonionic polyacrylamide）, PAC（polyaluminium chloride） and PFS（polyferrie sulfate）, the floeeulation performance of PAQD was the best. PAQD floeeulant was characterized by less floeeulant dosage, higher sedimentation rate, lower water content of the filter cake, clearer supernatant and lower remains of pollutants in papermaking wastewater.