分步投加FeSO_4·7H_2O、H_2O_2法预处理皮革鞣制废液试验研究  

Experimental research on the pretreatment of leather tanning waste water by stepwise adding FeSO_4·7H_2O and H_2O_2

作　　者：吴旭鹏[1] 蔡庆庆[1] 沈红池 姚立荣[2] 程寒飞[2] 张文艺[1] 

机构地区：[1]常州大学环境与安全工程学院,江苏常州213164 [2]中冶华天工程技术有限公司,江苏南京210019

出　　处：《应用化工》2016年第10期1917-1921,共5页Applied Chemical Industry

基　　金：江苏省科技支撑计划项目(BY2015027-03);常州市科技计划项目(CE20155061)

摘　　要：对皮革鞣制废液采用分步投加FeSO_4·7H_2O、H_2O_2法进行预处理,考察了FeSO_4·7H_2O、H_2O_2的投加方式与投加量、反应温度、pH值、反应周期等的影响。结果表明,最佳工艺参数为:温度50℃,pH值5,FeSO_4·7H_2O投加量5 mmol/L,H_2O_2用量50 mmol/L,反应周期3 h。在此工艺条件下,可使废液色度从40 000倍降为10倍,COD、总铬和Cr^(6+)浓度分别从2 700,19.27,18.78 mg/L降为426.7,0.162,0.15 mg/L,达到了《制革及毛皮加工工业水污染物排放标准》(GB 30486—2013)要求。方法主要是利用先投加FeSO_4·7H_2O还原Cr^(6+),搅拌反应一段时间后,再投加H_2O_2形成Fenton试剂。其去除机制有别于传统Fenton试剂,主要是针对皮革鞣制废液中的Cr^(6+)浓度高这一水质特色,先用Fe^(2+)还原Cr^(6+),并利用Cr_2O_72-的强氧化性,在酸性条件H+与H_2O_2的共同作用下,形成Fe^(2+)、Fe^(3+)、Cr^(3+)、Cr^(6+)、H_2O_2、·OH、OH-等离子的共氧化和共沉淀体系,实现色度、Cr^(6+)、COD和总铬的同步去除。The pretreatment technology of high concentration wastewater from leather tanning process by adding FeSO4·7H2O and H2O2 was developed. The methodology and its technological parameters,including the adding sequence of FeSO4·7H2O and H2O2,reaction temperature,p H and reaction time were studied. The results revealed that the chroma of wastewater decreased from 40 000 to 10 at optimum conditions of reaction temperature of 50 ℃,pH of 5,reaction time of 3 h,5 mmol / L and 50 mmol / L corresponding to the adding amounts of FeSO4·7H2O and H2O2 respectively. Moreover,the concentrations of COD,total chromium and Cr^6＋ were reduced from 2 700 mg / L,18. 78 mg / L and 19. 27 mg / L to426. 7 mg / L,0. 15 mg / L and 0. 162 mg / L,respectively. Which met the requirement of discharge standard of water pollutants for leather and fur making industry（ GB 30486—2013）. The possible mechanism of the proposed method in this study involved the reduction of Cr^6＋ with the addition of FeSO4·7H2O and Fenton reaction with the addition of H2O2,which was different with native Fenton reaction. Cr^6＋ could be reduced to Cr^3＋initially in the presence of Fe^2＋due to its strong oxidation,the Fenton reaction might be formed with the addition of H2O2,which might form co-oxidation and co-precipitation system of Fe^2＋,Fe^3＋,Cr^3＋,Cr^6＋,H2O2,·OH,OH-and other ions. Therefore,the synchronous removal of chroma,Cr^6＋,COD and total chromium can be achieved.

关 键 词：皮革鞣制废液 分步投加 Cr6+ 总铬 FENTON 

分 类 号：TQ610[化学工程—精细化工] TQ11