纳米微孔链状PAS-PDMDAAC混凝剂制备条件的优化与表征  

Optimization of the preparation conditions and characterization of PAS-PDMDAAC coagulant with nano-microporous chain shape

作　　者：朱天菊[1] 陈春燕[1] 来进和 刘蕊 ZHU Tianju;CHEN Chunyan;LAI Jinhe;LIU Rui(College of Chemistry and Chemical Engineering,Southwest Petroleum University,Chengdu 610500,China;Yumen Oilfield Branch,China National Petroleum Co.Ltd.,Jiuquan 735000,China)

机构地区：[1]西南石油大学化学化工学院,成都610500 [2]中国石油天然气股份有限公司玉门油田分公司,酒泉735000

出　　处：《环境工程学报》2020年第1期16-23,共8页Chinese Journal of Environmental Engineering

基　　金：国家水体污染控制与治理科技重大专项(2016ZX05062)

摘　　要：以硫酸铝(AS)和二甲基二烯丙基氯化铵聚合物(PDMDAAC)为原料制备了无机-有机复合混凝剂(PASPDMDAAC),并利用其对页岩气钻井废水中TOC的去除率为响应值,采用响应面法中Box-Behnken实验设计,优化了制备工艺条件。结果表明:复合混凝剂制备工艺条件对页岩气钻井废水中TOC的去除率影响显著性依次为反应温度>反应时间>Al/PDMDAAC质量比;在响应曲面法模拟优化条件下,PAS-PDMDAAC复合混凝剂对页岩气钻井废水中TOC的去除率为74.35%;当反应温度为70℃,反应时间为70 min,AS/PDMDAAC质量比为6时,制备的复合混凝剂对页岩气钻井废水中TOC的去除率偏差为0.72%,符合实验精度要求。通过微观结构表征发现:PAS-PDMDAAC复合混凝剂中存在聚合羟基铝;AS水解形成羟基铝后,通过静电作用与PDMDAAC复合成规则的纳米微孔链状空间结构,并通过混凝实验溶液中Zeta电位变化,进一步验证了复合混凝剂中因静电作用使其电中和能力减弱的结论,此时复合混凝剂的最佳pH为6,弱酸性条件可避免铝盐类复合混凝剂的沉淀,以上研究结果为提高无机-有机复合混凝剂的混凝效果提供了参考。An inorganic-organic composite coagulant PAS-PDMDAAC was prepared with aluminum sulfate(AS)and dimethyldiallylammonium chloride homopolymer(PDMDAAC),and was used to remove TOC in shale gas drilling wastewater.Then the TOC removal rate was taken as the response value,and the preparation process conditions were optimized by the Box-Behnken experimental design of the response surface method.The results showed that the significance of the effect of the preparation conditions of PAS-PDMDAAC on the TOC removal rate in shale gas drilling wastewater was following:the reaction temperature>reaction time>Al/PDMDAAC mass ratio.Under the optimum conditions through response surface method simulation,the TOC removal rate in shale gas drilling wastewater by composite coagulant PAS-PDMDAAC was 74.35%.At the reaction temperature of 70°C,the reaction time of 70 min,and the AS/PDMDAAC mass ratio of 6,the standard deviation of TOC removal rate in gas drilling wastewater for composite coagulant was 0.72%,which met the accuracy requirements of the experiment.Through the microstructural characterization,polymerized hydroxyaluminum was found in PAS-PDMDAAC composite coagulant.AS hydrolyzed to form hydroxyaluminum and it could combine with PDMDAAC to form a regular nanoporous chain-like space structure through electrostatic interaction.The Zeta potential variation in the coagulation test solution further verify that the complex electrostatic interaction might weaken its electrical neutralization ability,and the optimum pH of PAS-PDMDAAC composite coagulant was 6.At weak acid conditions,the use of aluminum salt composite coagulant should be avoided due to its hardly precipitation.This provides the theoretical support for the improvement of the coagualation effect of the inorganic-organic composite coagulant.

关 键 词：混凝剂 钻井废水 响应面法优化 表征 

分 类 号：X703[环境科学与工程—环境工程]