回流比对UASB反应器处理难降解化工综合废水运行性能的影响_刘新文

收稿日期:2006-05-12修回日期:2007-03-07作者简介:刘新文(1978-),男,汉族,山东泗水人,硕士,研究方向为环境生物技术。通讯作者:沈东升,E-mail:shends@zju.edu.cn回流比对UASB反应器处理难降解化工综合废水运行性能的影响刘新文1,沈东升2(1.宁波工程学院化工分院,浙江宁波315016;2.浙江大学环境工程系,浙江杭州310029)摘要:本试验研究了污水回流比(R)对UASB反应器处理难生物降解的化工综合废水(BOD5/CODCr～0.3)运行性能的影响。结果表明:回流比对CODCr去除率影响明显,当R=2时(水力负荷率HLR为0.426m3·m-3d-1,液体升流速UFV为0.0983m·h-1),CODCr最大去除率为60%,基质降解速率SDR为1.122kgCOD·m-3d-1。当R=3时(HLR0.432m3·m-3d-1,UFV0.131m·h-1),CODCr最大去除率为62.2%,SDR为1.163kgCOD·m-3d-1。回流作用强化了污染物与微生物细胞之间传质效果,可能是反应器运行性能提高的重要原因。另外,回流引起UASB反应器内部水力学特性发生改变,使基质浓度梯度减小且混合均匀,VFA的产生量减少,VFA积累引起的抑制作用被消除。关键词:难生物降解;化工废水;UASB反应器;回流比中图分类号:X703;S216.4文献标识码:A文章编号:1000-1166(2007)03-0014-05EffectofCirculationRatesonPerformanceofUASBReactorTreatingtheWastewaterContainingNondegradableSubstratefromChemicalIndustrial/LIUXin-wen1,SHENDong-sheng2/(1.DepartmentofChemicalEngineer-ing,NingboUniversityofTechnology,Ningbo315016,China;2.DepartmentofEnvironmentalEngineering,Zhe-jiangUniversity,Hangzhou310029,China)Abstract:EffectsofcirculationratesontheperformanceofUASBreactortreatingthewastewatercontainingnondegradablesubstratefromchemicalindustrialwerestudied.TheresultsdemonstratedthatcirculationrateshadobviouseffectonCODremoval.Whencirculationratewas2(HLR0.426m3·m-3d-1,UFV0.0983m·h-1),themaximumCODremovalratewas60%andsubstratedegradationratewas1.122kgCOD·m-3d-1.Whencirculationratewas3(HLR0.432m3·m-3d-1,UFV0.131m·h-1),themaximumCODremovalratewas62.2%andsubstratedegradationratewas1.163kgCOD·m-3d-1.CirculationenhancingthemasstransferringbetweenpollutantsandmicrobescouldbetheimportantreasonimprovingUASBperformance.Furthermore,circulationcouldcausethevariationofhydrauliccharacteristicsinUASBreac-tor,andsothesubstrateconcentrationgradientdecreasedandthesubstratetendtouniformlymixed.Meanwhile,theVFAproductiondecreasedandtheinhibitionresultingfromtheaccumulationofVFAwaseliminated.Keywords:difficultbiodegradation;chemicalcompositewastewater;UASBreactor;recirculationrate1引言目前我国的工业化发展速度迅速,制药、印染、农药等高分子有机合成工业的发展为国民经济的发展和人民的生活提高做出了突出的贡献。但工业的发展势必伴有大量工