芬顿-生物接触氧化法处理MDF纤维干燥尾气净化系统含污废水  

Treatment of medium density fiberboard fiber dry exhaust purification system wastewater by Fenton-biological method

作　　者：余晓 朱南峰 陆义磊 张磊[2] 周培国[2] YU Xiao;ZHU Nanfeng;LU Yilei;ZHANG Lei;ZHOU Peiguo(College of Materials Science and Engineering,Nanjing Forestry University,Nanjing 210037,China;College of Biology and the Environment,Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京210037 [2]南京林业大学生物与环境工程学院,南京210037

出　　处：《林业工程学报》2018年第6期104-109,共6页Journal of Forestry Engineering

基　　金：国家重点研发计划项目(2016YFD0600703);江苏省科技支撑计划重点项目(BE2016304);江苏高校优势学科建设工程资助项目(PAPD)

摘　　要：中密度纤维板(MDF)纤维干燥尾气净化系统产生的含污废水成分复杂,其甲醛质量浓度高达1 080 mg/L,COD质量浓度为20 g/L,悬浮物含量为500 mg/L,含盐量为300 g/L,还含有氯仿、甲苯、4-异丙基甲苯等多种有机物,p H为6,属于难降解有机废水,很难用生物法直接处理。笔者利用Fenton氧化法和生物接触氧化法的组合工艺,探讨了对该废水的净化效果。试验结果表明,Fenton预处理的优选工艺条件:Fe^(2+)/H_2O_2摩尔比为0.3∶1.0、初始p H为3、反应温度为40℃、反应时间为1 h;处理后,该废水中甲醛质量浓度可以降到450 mg/L,COD质量浓度降至10 g/L。由于生物接触氧化法对进水的COD质量浓度要求为1 500 mg/L以下,故在进行生物处理前将该预处理废水稀释10倍左右。生物接触氧化法的优选工艺条件:COD质量浓度为1 000 mg/L、HRT为10 h、气水比为20∶1。研究发现,采用Fenton-生物接触氧化法处理该废水,甲醛去除率可达100%,达到《污水综合排放标准》(GB 8978—1996)一级排放标准,说明Fenton-生物接触氧化法组合工艺的推广应用,将会有利于降低纤维板行业的环境污染风险,提高水资源利用率,推进纤维板行业向绿色、环保的产业升级,具有良好的社会、经济和环境效益。A large amount of wastewater containing high-concentration of formaldehyde as high as 1 080 mg/L could be generated from the spraying operation used for dissolving formaldehyde in the fiber drying exhaust gas purification system during the production of medium density fiberboard(MDF).It is difficult to be handled directly by the traditional biological methods to remove formaldehyde,and also called as a refractory organic wastewater due to its complex components including up to 20 g/L of COD,500 mg/L of suspended solids,300 g/L of salinity,and a few kinds of organic compounds such as chloroform,toluene and 4-isopropyl toluene,with a pH value of 6.In this study,the combined process of Fenton oxidation and biological contact oxidation was used to investigate the purification effect of the wastewater.The results in the Fenton-pretreated experiments showed that the processing parameters were optimized as follows:0.3∶1.0 of Fe^2+/H2O2,the initial pH value of 3,the reaction temperature of 40℃,and the reaction time of 1 h.After the treatment,the formaldehyde concentration in this wastewater was reduced to 450 mg/L and COD concentration was dropped to 10 g/L,which indicated that the Fenton reagent can effectively oxidize various recalcitrant organic compounds rapidly to generate hydroxyl radicals for the decrease of formaldehyde in wastewater.Then the Fenton-pretreated wastewater was diluted by 10 times or so for the biological contact oxidation,of which the optimum conditions were the influent COD concentration of 1 000 mg/L,high resolution time of 10 h,gas-water ratio of 20∶1.Under these conditions,the formaldehyde in the wastewater was removed completely with the removal rate up to 100%.Therefore,using the combined process of the Fenton-pretreatment and biological contact oxidation,the effluent from the fiber drying exhaust purification system during the production of the MDF can meet the requirements of the primary discharge standards of“Integrated Wastewater Discharge Standard”(GB 8978-1996).All these resul

关 键 词：中密度纤维板 尾气净化系统 芬顿法 生物接触氧化法 甲醛废水 

分 类 号：TS653.6[轻工技术与工程]