Ultrasound-initiated synthesis of cationic polyacrylamide for oily wastewater treatment: Enhanced interaction between the flocculant and contaminants
Ultrasound-initiated synthesis of cationic polyacrylamide for oily wastewater treatment: Enhanced interaction between the flocculant and contaminants
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用于含油废水处理的超声波引发合成阳离子聚丙烯酰胺：增强絮凝剂和污染物之间的相互作用
DOI：
10.1016/j.ultsonch.2017.11.006
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Shixin Zhang
中科院分区：
文献类型：
--
作者：
chuanliang zhao;huaili zheng;Baoyu Gao;Yongzhi Liu;Jun Zhai;Shixin Zhang
絮凝剂与油的弱相互作用是含油废水处理的主要瓶颈。针对这一问题，采用超声引发聚合技术合成了一种具有阳离子微嵌段结构和苯环疏水基团的新型絮凝剂PAB，并将其应用于水中除浊除油。为了避免传统模板和胶束共聚合中不必要的添加试剂，采用在水溶液中具有自组装能力的表面活性单体氯化苄（甲基丙烯酰氧乙基）二甲基铵（BMDC）合成絮凝剂。用电导法和表面张力法测得BMDAC的临界缔合浓度为0.014 mol·L-1。竞聚率、序列长度分布统计分析和1H NMR结果为阳离子微嵌段共聚物的合成提供了依据。表观粘度的测定表明PAB具有明显的疏水缔合特性。絮凝试验表明，PAB的加入大大提高了絮凝性能，在投加量为40 mg·L-1、pH为7.0时，对油和浊度的去除率均达到最大值（87.5%和92%）。絮凝机理研究表明，电中和、吸附架桥和疏水缔合作用的协同作用起着重要作用。由于絮凝剂与油的相互作用增强，PAB形成的絮体大而致密，不易破碎，且易于再生。综上所述，本研究可为有机絮凝剂在含油废水处理中的应用设计提供重要参考。
Weak interaction between flocculants and oil is a main bottleneck in the treatment of oil-containing wastewater. To solve this problem, a novel flocculant PAB with cationic micro-block structure and hydrophobic groups of benzene rings was synthesized by ultrasound initiated polymerization technique and applied to remove turbidity and oil from water. To avoid unnecessary addition of reagents in traditional template and micellar copolymerization, surface-active monomer benzyl(methacryloyloxyethyl)dimethylammonium chloride (BMDAC) with self-assembly ability in aqueous solution was employed to synthesize flocculants. The critical association concentration of BMDAC measured by conductivity and surface tension methods was 0.014 mol·L−1. The results of reactivity ratio, statistical analysis of sequence-length distribution and 1H NMR provided evidence for the synthesis of copolymer with cationic micro-block. In addition, the apparent viscosity measurement indicated that PAB had an obvious hydrophobic association property. Finally, flocculation tests demonstrated that flocculation performance was greatly improved by adding PAB and the removal rate of oil and turbidity both reached the maximum (87.5% and 92%) at dosage of 40 mg·L−1 and pH of 7.0. Flocculation mechanism investigation demonstrated that the cooperation of charge neutralization, adsorption bridging, and hydrophobic association effect played an important role. The formed flocs by PAB was large, compact, difficult to break, and easy to regrow because of the enhanced interaction between flocculants and oil. In summary, this study can provide important reference in the design of organic flocculants in oily wastewater treatment applications.