壳聚糖季铵盐絮凝剂处理丁苯橡胶废水的研究

以壳聚糖(CTS)为母体,3-氯-2-羟丙基三甲基氯化铵(CTA)为改性剂,合成了壳聚糖季铵盐阳离子型高分子絮凝剂2-羟丙基三甲基氯化铵壳聚糖(HTCC),以其对高岭土悬浊液的浊度去除率为指标优化合成条件,以HTCC分别与PAC及PAM复配,絮凝处理丁苯橡胶废水.结果表明,最佳合成条件为:质量比MCTS: MCTA: MNaOH =1:2:1.2、反应温度60℃、反应时间3h,在此条件下合成的HTCC对高岭土悬浊液的浊度去除率达96.46%;HTCC+PAC复配在pH6.0~8.0对丁苯橡胶废水的絮凝效果较好,出水余浊<2NTU,色度去除率达92.98%,COD去除率达32.0%;HTCC+PAM复配在pH5.0~8.9对丁苯橡胶废水的絮凝效果最好,余浊<3NTU,COD去除率46.0 %,且投药量小, pH适宜范围宽,优势比较明显.以HTCC与PAC、PAM分别复配处理丁苯橡胶废水可减轻后续生化处理的负荷,降低PAC、PAM的投加量,从而减小出水中残余铝和残余丙烯酰胺单体的含量.

Preparation of chitosan quaternary ammonium and flocculation of styrene-butadiene rubber wastewater

Cationic flocculant 2-hydroxypropyltrimethyl-ammonium chloride chitosan(HTCC) was prepared by the reaction of chitosan(CTS) with 2-hydroxypropyltrimethyl-ammonium chloride(CTA).The optimum synthesis conditions of HTCC was determined according to its turbidity removal efficiency for kaolin suspension as follows: mass ratio MCTS: MCTA: MNaOH =1:2:1.2,reaction temperature was 60℃ and reaction time was 3h.The flocculation experiment showed the turbidity removal efficiency of HTCC was higher,and the applicable pH range of HTCC was broader compared to CTS.The styrene-butadiene rubber wastewater was treated by the composite flocculant HTCC+PAC.The residual turbidity reached under 2 NTU,the removal rates of COD and chromaticity reached to 32.0% and 92.98% respectively.The applicable pH value range for flocculating the sample by HTCC+PAC was from 6.0 to 8.0.This styrene-butadiene rubber wastewater was also treated by composite flocculant HTCC+ PAM(anion).The residual turbidity reached under 3 NTU,and the removal rate of COD was the most high,reaching to 46.0 %,and the dosage was lower.The applicable pH value range for flocculating the sample by HTCC+PAM was wider from 5.0 to 8.9.The use of HTCC combined with PAC or PAM as flocculants in the preceding treatment of styrene-butadiene rubber wastewater would decrease the load of subsequent biochemical treatment and the dosages of PAC or PAM,thus decrease the residual aluminum and residual acrylamide monomer in the treated water.