味精生产中离子交换废水的预处理技术研究_白晓慧

味精生产中离子交换废水的预处理技术研究白晓慧1,陈群燕2(1.浙江大学环境工程系,浙江杭州310029;2.杭州市余杭区环境保护局,浙江杭州311100)[摘要]采用电化学法、吹脱法和化学沉淀法对味精废水中离子交换废水的预处理进行了试验研究。结果表明:以铸铁屑为主的铁碳法,当HRT为2h时,pH可从1.97升至4.88,可大大减少后续中和吹氨所需石灰量,Fe-C还原对去除COD、氨氮和提高可生化性无明显效果。pH中和至9.5～10,鼓气量在100m3/h左右,水温55℃左右,经8h,可将原水NH3-N从12000mg/L左右降至4000mg/L左右,脱除率65%以上。磷酸氨镁法去除废水中NH4+-N,在n(Mg2+)∶n(PO43-)∶n(NH4+-N)=1∶1∶1(物质的量比)时,随废水pH升高,NH4+-N去除率逐步增大,pH为10时其去除率达到54%。[关键词]味精废水;离子交换废水;预处理[中图分类号]X703.1[文献标识码]A[文章编号]1005-829X(2002)01-0034-03PretreatmenttechnologyofionexchangewastewaterreleasedfromtheproductionofmonosodiumL-glutamateBAIXiao-hui1,CHENQun-yan2(1.DepartmentofEnvironmentalEngineering,ZhejiangUniversity,Hangzhou310029,China;2.YuhangDistirctEPB,Hangzhou311100,China)Abstract:Experimentshavebeenconductedtopretreattheionexchangewastewater(themainpartoftheMonosodiumL-glutamate(MSG)wastewater)bymeansofFe-CdeoxidizationtoincreasethepHandbiodegradation,limecounteractionandaerationbyairorchemicaldepositiontoremoveammonia.Theexperi-mentresultsshowthatFe-CdeoxidizationbytheuseofcastironbitscanincreasethepHfrom1.97to4.88,whentheHRTis2hsothatthelimequantityforammoniaremovalcanbereducedgreatly.ButthereislittledifferenceinthecostofpHadjustbyFe-Cdeoxidizationandlimecounteration,andnoobviouseffectsarefoundfortheremovalofCODandammonia,sodoestheincreaseofbiodegradation.Theinfluentammoniacanbere-ducedfrom12000mg/Lto4000mg/Lafter8hreaction,andtheremovalratecanbeabove65%,whenthepHis9.5～10;theairquantityisabout100m3/h;thewastewatertemperatureisheatedto55℃.Theexperi-mentalresultofammoniaremovalbymeansofchemicaldepositionshowsthat,whenn(Mg2+)∶n(PO43-)∶n(NH4+-N)=1∶1∶1,ammoniaremovalrateincreaseswiththeincreaseofpH.WhenthepHis10,theammo-niaremovalratecanreach54%.Keywords:MonosodiumL-glutamate(MSG)wastewater;ionexchangewastewater;pretreatment采用发酵法制取味精的生产废水中包括离子交换废水、精制水、洗米水和生活污水。味精废水的特征主要由离子交换废水决定,后者具有低pH值、高有机物浓度、高氨氮和高硫酸盐,有时Cl-含量也很高。离子交换废水中残留谷氨酸的质量分数约为0.2%～0.3%,其COD、NH4+-N质量浓度分别高达30000mg/L和13000mg/L,pH为1～2,其中部分离子交换废水经制SCP并与其他废水混合后NH4+-N、SO42-质量浓度仍有3300mg/L和4167mg/L,无法进行生物处