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ID:5674503
大小:2.40 MB
页数:93页
时间:2017-12-22
《小型电镀厂废水处理工程优秀毕业设计完整版(含图纸)》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、南华大学城市建设学院毕业设计摘要:电镀是世界三大污染行业之一,随着我国乡镇电镀企业的迅速发展,我国的电镀污染问题日趋严重。本文首先阐述了我国电镀废水的污染现状以及对人类产生的危害,在对化学处理、离子交换、电解法、生物处理等电镀废水处理方法的分析和比较后,结合乡镇电镀企业要求工艺简单、成本低等特点,决定采用NaHSO4化学还原沉淀法处理该企业的含铬、锌废水。本工艺是在pH=2.5时用NaHSO4溶液将Cr6+还原为Cr3+,在用NaOH溶液调节pH=8后生成Cr(OH)3和Zn(OH)2沉淀,在添加絮凝剂PAC和PAM
2、后生成的絮体在斜板沉淀池中沉淀,出水经砂滤器过滤后可回用于砂滤器反冲洗水及各种溶液的配制,或者达标排放,而污泥则统一交于专业的环保公司处理。在设计中采用了较为先进的ORP测定仪、在线pH计和液位计实现反应过程的自动控制。通过设计计算确定了各构筑物的尺寸以及设备的选型,并对设计和操作管理中的要求进行了说明,最后对电镀废水治理的前景进行了展望。关键字:电镀废水;Cr;Zn;化学还原沉淀法Abstract:Withthespeedydevelopmentoftheelectroplatingenterpriseintown
3、sinourcountry,electroplatingindustry,asoneofthebiggestpollutionsintheworld,causesthepollutionmoreandmoreseverely.Inthispaper,describesthepresentsituationoftheelectroplatingeffluentwaterpollutionandthegreatharmitmakestothehumankindhasbeendescribed.Aftertheanalys
4、esandthecomparisonofdifferentwaysfortreatmentofelectroplatingeffluentsuchaschemicaltreatmentprocess、ionexchangeprocess、electrolyticmethodandbiologicalprocess,IdecidetoadopttheNaHSO4reduction-precipitationtotreatthewastewatercontainingCrandZnforthecorporations,c
5、onsideringthefeaturesofthetownelectroplatingcorporations’demandsofsimpletechniques,lowcosts,etc.ThistechnologyistodeoxidizeCr6+intoCr3+byNaHSO4solutionatthePH=2.5,thenadjustthePHto8withNaOHsolutiontomakeCr(OH)3andZn(OH)2sediment.Theflocculatingconstituent,forme
6、dafteraddingtheflocculatingagentPACandPAM,canbedepositedintheslopingplanksettlingtank.Thewaterleftafterfiltratingthroughasankfiltercanberecycledas第93页共93页南华大学城市建设学院毕业设计thebackwashofsankfilterandbeusedinconfectingvarioussolutionsorbedischargedanemissionstandard.
7、and,thesludgecanbesolvedbytheprofessionalenvironmentalprotectingcompanies.ItadoptssomerelativelyadvancedequipmentsuchasmeasuringelementofORP、pHmeterandcontentgaugerealizetheautomataofthereactionprocess.Throughelaboratedesignationandcalculation,thesizeofeachcons
8、tructandthetypeelectionoftheequipmenthavebeenascertained.Besides,withexplanationsaboutthedesignationandthedemandsintheoperatingmanagement,itfinallycomestotheprospectofsolvin
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