印染废水中聚乙烯醇浆料的高效去除及六价铬的协同还原  

Efficient removal of polyvinyl alcohol and synergistic reduction of Cr(VI)from textile wastewater

作　　者：李方[1] 潘航 章耀鹏 马慧婕 沈忱思[1] LI Fang;PAN Hang;ZHANG Yaopeng;MA Huijie;SHEN Chensi(College of Environmental Science and Engineering,Donghua University,Shanghai 201620,China;Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092,China)

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《纺织学报》2023年第3期147-157,共11页Journal of Textile Research

基　　金：上海市自然科学基金项目(21ZR1401500);中央高校基本科研业务费专项资金资助项目(2232021G-11)。

摘　　要：聚乙烯醇(PVA)是印染废水有机污染物的主要来源,同时含铬显影剂的使用导致部分印染废水含有六价铬(Cr(Ⅵ)),高浓度PVA及高毒性Cr(Ⅵ)的协同处理技术亟待突破。利用过硫酸盐热活化可引发聚合物发生自由基交联反应的特点,研究印染废水中PVA及Cr(Ⅵ)协同处理的方法。考察了过硫酸盐投加量、反应温度、初始pH值、Cr(Ⅵ)初始浓度等因素对二者去除效率的影响,借助X射线光电子能谱、凝胶渗透色谱等手段分析了反应沉淀物及剩余废水中残留物,探索了PVA及Cr(Ⅵ)的协同处理机制。结果表明:当过硫酸盐质量浓度为8.0 g/L、反应温度为70℃、废水pH值小于6时,模拟印染废水的化学需氧量去除率达91.9%,PVA去除率可达98.0%,Cr(Ⅵ)还原率为94.3%;过硫酸盐热活化引发PVA自由基交联及PVA的还原性是PVA高效沉淀及Cr(Ⅵ)有效还原的主要原因,此类浆料与重金属污染物的协同处理在印染废水方面具有一定的应用前景。Objective Polyvinyl alcohol(PVA),a major sizing agent used in textile weaving,is eluted in the pretreatment of textile wet processing and becomes the main source of organic pollutants in textile wastewater.Meanwhile,textile industries sometimes adopt chromium-containing developers for the printing screen,leading to Cr(Ⅵ)pollution in the textile wastewater.The simultaneous treatment technology of high concentration of PVA and highly toxic Cr(Ⅵ)in printing and dyeing wastewater is of great concern.Persulfates can initiate the free radical crosslinking of the polymeric chain,which is considered as one of the solutions for the crosslinking-induced precipitation of PVA.Additionally,under high temperature and acidic conditions,PVA can reduce Cr(Ⅵ)to Cr(Ⅲ)which is less toxic.Thus,in the thermally activated persulfate system,with the rapid precipitation of high concentration of PVA,the effective reduction of Cr(Ⅵ)becomes possible.Method To achieve the simultaneous removal of PVA and Cr(Ⅵ)from wastewater,persulfate(K_(2)S_(2)O_(8))was chosen as free radical crossling initiator.Simulative wastewater containing the high concentrations of PVA(10 g/L)and the coexisting Cr(Ⅵ)was the object of treatment.The thermal activation was used to activate K_(2)S_(2)O_(8) because desizing wastewater is often processed at high temperatures(70-80°C)and Cr(Ⅵ)is more easily reduced under high temperature.The remoal performance of PVA and chemical oxygen demand(COD)and the reductive efficiency of Cr(Ⅵ)were studied,with specific attention paid to the performance of free radical-induced crosslinking of PVA and the production of free radicals and explored the critical factors controlling their efficacy by electron spin-resonance spectroscopy(ESR).In addition,the possible underlying mechanism was studied using X-ray photoelectron spectroscopy(XPS),gel permeation chromatography(GPC),and gas chromatography-mass spectrophotometry(GC-MS).Results The K_(2)S_(2)O_(8) dosage,reaction temperature,and pH value of the solution were the k

关 键 词：聚乙烯醇 六价铬 过硫酸盐 印染废水 协同处理 

分 类 号：X703.1[环境科学与工程—环境工程]