Wu Pei, Yi Jiaxiang, Feng Li, Li Xuhao, Chen Yao, Liu Zhen, Tian Shenghai, Li Shiyao, Khan Sarfaraz, Sun Yongjun
School of Civil Engineering and Architecture, Chongqing University of Science and Technology, Chongqing 401331, China; Chongqing Xin Yun Chuang Institute of Environmental Protection Research Co. Ltd, Chongqing 402566, China.
Chongqing Xin Yun Chuang Institute of Environmental Protection Research Co. Ltd, Chongqing 402566, China; School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.
Int J Biol Macromol. 2020 Jul 15;155:708-720. doi: 10.1016/j.ijbiomac.2020.04.011. Epub 2020 Apr 4.
In this study, a new type of graft modified flocculant (CS-g-PAD) was copolymerized of AM, DAC and chitosan (CS) by microwave assisted initiation and used for sludge conditioning and dewatering. The effect of reaction conditions on microwave assisted copolymerization was investigated and their optimal values were obtained by orthogonal experiments. The structure and chemical properties of CS-g-PAD were characterized and the results indicated that microwave assisted polymerization can cause the generated side polymer chain of PAD to react with the -NH active group in CS. Thus, the graft copolymerization occurred at amino group connected with C site. Compared with CCPAM, PAD and CS, the synthesized CS-g-PAD exhibits superior sludge dewatering performance (FCMC: 72.1%, SRF: 4.5 × 10 m/kg, d: 679.556 μm, D: 1.72, floc sedimentation rate: 5.72 cm/min) in a wide pH range (pH = 3.5-9.5). Because CS-g-PAD contains a large amount of cationic DAC and positively charged CS as well as many functional groups on CS, it increases the charge neutralization, electrical patching and adsorption capability. Additionally, the grafting PAD on CS has a good extension in solution to increase its adsorption bridging effect. The new grafted CS-g-PAD is promising and has great practical application value in sludge dewatering and condition.
在本研究中，通过微波辅助引发使丙烯酰胺（AM）、二甲基二烯丙基氯化铵（DAC）和壳聚糖（CS）共聚合成了一种新型接枝改性絮凝剂（CS-g-PAD），并将其用于污泥调理和脱水。研究了反应条件对微波辅助共聚的影响，并通过正交实验获得了其最佳值。对CS-g-PAD的结构和化学性质进行了表征，结果表明微波辅助聚合可使生成的PAD侧聚合物链与CS中的-NH活性基团发生反应。因此，接枝共聚发生在与C位点相连的氨基处。与阳离子型聚丙烯酰胺（CCPAM）、PAD和CS相比，合成的CS-g-PAD在较宽的pH范围（pH = 3.5 - 9.5）内表现出优异的污泥脱水性能（自由水含量：72.1%，比阻：4.5×10 m/kg，d：679.556μm，D：1.72，絮体沉降速率：5.72 cm/min）。由于CS-g-PAD含有大量阳离子型DAC和带正电荷的CS以及CS上的许多官能团，它提高了电荷中和、电补丁和吸附能力。此外，在CS上接枝PAD在溶液中有良好的伸展性，以增强其吸附架桥作用。新型接枝产物CS-g-PAD具有广阔的应用前景，在污泥脱水和调理方面具有很大的实际应用价值。
