Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China.
Jiangsu Key Laboratory of Industrial Water-Conservation & Emission Reduction, College of Environment, Nanjing Tech University, Nanjing 211800, China.
Sci Total Environ. 2017 Dec 31;609:410-418. doi: 10.1016/j.scitotenv.2017.07.192. Epub 2017 Jul 26.
In this study, maleyl chitosan-graft-polyacrylamide (MHCS-g-PAM), a novel chitosan-based flocculant, was prepared through UV irradiation, and maleyl chitosan (MHCS) was designed and prepared with maleic anhydride and acrylamide (AM) through maleyl acylation reaction. The effects of monomer concentration, MHCS-to-AM ratio, illumination time, initiator concentration, pH on viscosity, and grafting efficiency were investigated to optimize the synthesis of these substances. MHCS-g-PAM was characterized through Fourier transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectroscopy, scanning electron microscopy, and thermal gravimetric analysis. Flocculation mechanisms in alga-containing wastewater at various pH levels and dosages were examined in detail on the basis of zeta potential measurements. Zeta potential experiments indicated that the adsorption-bridging and charge neutralization mechanisms played an important role in algal removal. Flocculation tests on algal removal demonstrated that the flocculation performance of MHCS-g-PAM was more effective than that of cationic polyacrylamide, polyferric sulfate, and polymeric aluminium. The optimal Chl-a and COD removal rate obtained by MHCS-g-PAM was 98.6% and 94.9% at pH7 and 4mg·L, respectively.
在这项研究中，通过紫外线照射制备了一种新型壳聚糖基絮凝剂马来酰基壳聚糖接枝聚丙烯酰胺（MHCS-g-PAM），并通过马来酰化反应设计和制备了马来酸酐和丙烯酰胺（AM）的马来酰基壳聚糖（MHCS）。考察了单体浓度、MHCS 与 AM 的比例、光照时间、引发剂浓度、pH 值对粘度和接枝效率的影响，以优化这些物质的合成。通过傅里叶变换红外光谱、核磁共振氢谱、扫描电子显微镜和热重分析对 MHCS-g-PAM 进行了表征。基于zeta 电位测量，详细研究了不同 pH 值和剂量下含藻废水中的絮凝机理。zeta 电位实验表明，吸附架桥和电荷中和机制在藻类去除中起着重要作用。藻类去除的絮凝试验表明，MHCS-g-PAM 的絮凝性能优于阳离子聚丙烯酰胺、聚合硫酸铁和聚合铝。在 pH7 和 4mg·L 下，MHCS-g-PAM 获得的最佳 Chl-a 和 COD 去除率分别为 98.6%和 94.9%。
