强化混凝去除循环水溶解性有机物特性研究

摘要

循环水中有机物浓度高易引起微生物滋长和膜污堵,提高循环水利用率必须对其加以处理.采用传统化学分析,结合紫外-可见光谱、凝胶色谱和三维荧光等手段,研究了强化混凝对循环水中有机物的去除特性.结果表明:(1)在0～120 mg/L内,随FeCl3投加量增加,混凝对有机物去除率增加;溶解性有机物分子缩合度降低,分子量减小.(2)在FeCl3质量浓度为120 mg/L条件下,混凝对总有机碳(TOC)和溶解性化学需氧量(SCOD)去除率分别为54.06％和33.33％;腐殖质类物质C1、C2和蛋白质类物质C3的荧光强度Fmax值分别下降了48.02％、66.38％和22.27％.说明强化混凝可有效降低循环水中有机物浓度,特别是去除难被生物降解的腐殖质类物质效果明显,因而可通过旁流强化混凝处理循环水,提高循环水系统运行稳定性,为循环水进一步进行膜处理奠定良好基础.%The high concentration of organic matter in circulating water may easily cause microbial growth and membrane fouling.Removing organic matter could improve the utilization of circulating water.The removal characteristics of dissolved organic matter in the circulating water by enhanced coagulation were investigated through conventional chemical analysis in combination with UV-visible spectra,gel filtration chromatography (GPC) and three-dimensional fluorescence.The results indicated that with the increase ofFeC13 dosage within the range of 0-120 mg/L,the DOM removal rate went up with molecules condensation degree reduced and the molecular weight decreased.Under the condition of FeC13 dosage of 120 mg/L,the removal rate of TOC and SCOD were 54.06％ and 59.71％,respectively;fluorescence intensity Fmax of humic substances C 1,C2 and protein materials C3 were down 48.02％,66.38％ and 22.27％,respectively.Enhanced coagulation could effectively reduce the DOM in circulating water.Especially for those humic substances,which was difficult to be biodegradable,the removal effect was significant.Therefore,enhanced coagulation treatment of circulating water could be used to improve the operation stability of circulating water system and lay a good foundation for the further membrane treatment of circulating water.