两性生物基絮凝剂制备及其处理造纸废水性能评价

Synthesis and Performance Evaluation of an Amphoteric Bio-based Flocculant for Papermaking Wastewater Treatment

关键词:  壳聚糖季铵盐  羧甲基纤维素  两性生物基絮凝材料  絮凝  造纸废水

Key Words:chitosan quaternary ammonium salt  carboxymethyl cellulose  amphiphilic bio-based flocculating material  flocculation  papermaking wastewater

摘要:本研究以壳聚糖季铵盐（HTCC）和羧甲基纤维素（CMC）为原料，通过戊二醛交联，制备了一种两性生物基絮凝材料（HTCC-g-CMC）。采用傅里叶变换红外光谱、热重分析对HTCC-g-CMC进行表征，并将其应用于高岭土悬浊液和OCC造纸废水的絮凝处理以评价其絮凝性能。结果表明，HTCC与CMC通过缩醛反应成功合成了具有阴阳离子两性的HTCC-g-CMC；当pH值为4时，不添加PAC，HTCC-g-CMC絮凝高岭土悬浊液最小浊度为42.1 NTU，当pH值分别为6、10时，在添加PAC的条件下，HTCC-g-CMC絮凝高岭土悬浊液最小浊度为2.5、4.5 NTU；将HTCC-g-CMC和商业APAM、CPAM对造纸废水直接进行絮凝处理，当用量为12 mL时，废水的浊度和COD_Cr去除率分别为88.7、81.2、35.6 NTU和66.2%、63.6%、70.0%，表明HTCC-g-CMC絮凝在浊度和COD_Cr去除率方面与商业PAM的效果相当。

Abstract:An amphoteric bio-based flocculant (HTCC-g-CMC) was prepared by cross-linking glutaraldehyde with chitosan quaternary ammonium salt and carboxymethyl cellulose. The HTCC-g-CMC was characterized by fourier transform infrared spectroscopy and thermogravimetric analysis. The product was applied to flocculation treatments of kaolin suspension and actual papermaking wastewater to evaluate its flocculation effect. The results showed that the HTCC-g-CMC products with anionic and cationic groups were successfully synthesized by HTCC and CMC through aldolization. The minimum turbidity using HTCC-g-CMC for flocculating kaolin suspension was 42.1 NTU at pH value 4 without adding PAC. The minimum turbidities of HTCC-g-CMC with adding PAC for flocculating kaolin suspension were 2.5, 4.5 NTU at pH value 6, 10 respectively. HTCC-g-CMC was used to flocculate papermaking wastewater comparing with commercial APAM and CPAM, when dosage was 12 mL, the turbidities and COD_Cr removal rates of wastewater were 88.7、81.2、35.6 NTU and 66.2%, 63.6%, 70.0%, respectively. It indicated that the HTCC-g-CMC flocculant was basically equivalent to the commercial PAM in terms of turbidity and COD_Cr removal rate, and could be applied in the flocculation and precipitation processes of papermaking wastewater treatment.