CauseAnalysisandCountermeasuresforDeclineofDissolvedOxygeninAerobicTankLuoPeng-fei,PeiYue-fei(QinghuaCoalChemicalIndustryCo.,Ltd.ofBaotouIron&Steel(Group)Co.,Ltd.,Baotou014010,InnerMongoliaAutonomousRegion,China)　　Abstract:Inthispaper,itisconsideredtobethemaincausefordeclineofdissolvedoxygenthattheloadoforganicmatterinaerobictankincreasesrapidlybyanalyzingthetypicalexamplefordeclineofdissolvedoxygeninaerobictankofbiochemicalsystemforcokingwastewater.Verifiedbyexperiment,theconcentrationofdissolvedoxygeninaerobictankcouldreturntonormalwithin1~2daysbytakingsuchmeasuresasincreasingtheaerationrateofaerobictank,addingthewaterwithlowCODconcentrationintoaerobictankandstrictlycontrollingtheamountoforganicmatterenteringaerobictank.　　Keywords:dissolvedoxygen;aerobictank;organicmatter　　某焦化厂废水处理系统负责处理厂区内焦化废水、蒸氨废水、甲醇生产废水、生活污水等,污水处理生物反应池采用厌氧—缺氧—好氧工艺,即 A/A/O法,处理能力为 380m3 /h,分为东、西两个系统,好氧池每个系统由 4个池体串联运行。