壳聚糖季铵盐絮凝剂处理丁苯橡胶废水的研究

摘要

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,在此条件下台成的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.%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'C and reaction time was 3h. The floccularlon 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.