毕业论文-电镀废水的处理-修改

夜大学本科毕业论文（设计）题目（中文）：电镀废水的处理（英文）：Treatmentofelectroplatingwastewater学院年级专业学生姓名学号指导教师完成日期2015年10月上海师范大学本科毕业论文（设计）诚信声明本人郑重声明：所呈交的毕业论文（设计），题目《电镀废水的处理》是本人在指导教师的指导下，进行研究工作所取得的成果。对本文的研究做出重要贡献的个人和集体，均已在文中以明确方式注明。除此之外，本论文（设计）不包含任何其他个人或集体已经发表或撰写过的作品成果。本人完全意识到本声明应承担的法律责任。作者签名：日期：年月日摘要电镀废水是一种常见的工业废水来源，电镀废水的成分常常是同时含有多种污染物，其中有毒有害的物质有铬、镍、氰化物、铜等。对此类废水的处理常采用物理、化学和生物的方法。因电镀种类的不同，电镀废水的性质和含量有所差异，因此在处理方法上也要分类处理和综合处理相结合，用合适的方法处理电镀废水。本中总体概况了电镀废水的处理方法，特别对常见的含氰废水、含铬废水、酸碱废水等处理进行详尽的说明。结合分系统处理和综合处理的特点，着重介绍了电镀废水分系统处理的概况。关键词：电镀废水;分系统处理;重金属离子;酸碱废水；AbstractElectroplatingwastewaterisakindofcommonindustrialwastewater,whichisusuallyusedinphysicalandchemicaltreatment.Becauseofthedifferenttypesofelectroplating,thenatureandcontentofelectroplatingwastewateraredifferent,sothetreatmentmethodshouldbeclassifiedastreatmentandcomprehensivetreatment.Thegeneralsituationoftheelectroplatingwastewatertreatmentmethods,especiallythecommoncyanidecontainingwastewater,chromiumcontainingwastewater,acidandalkaliwastewaterprocessingaredetailedinstructions.Thecharacteristicsofthetreatmentandcomprehensivetreatmentofthesystemareintroduced,andthegeneralsituationofthetreatmentofthewastewatersystemisintroduced.Keywords:electroplatingwastewater;systemtreatment;heavymetalion;acidandalkaliwastewater;目录上海师范大学夜大学本科毕业论文（设计）诚信声明………………………………I上海师范大学夜大学本科毕业论文（设计）选题登记表…………………………II上海师范大学夜大学本科毕业论文（设计）指导记录表…………………………Ⅳ摘要······································································································V1引言·····································································································11.1电镀与电镀废水················································································11.1.1电镀废水的概况·····································································11.1.2电镀及电镀废水来源··································································21.1.3电镀废水的性质和危害·······························································31.2我国电镀污染现状·············································································41.3电镀废水处理技术综述·······································································51.3.1物理方法·················································································51.3.2化学方法·················································································61.3.3物理化学方法···········································································81.3.4生物处理方法···········································································92电镀废水的处理方法···········································································112.1含氰废水处理················································································112.2含铬废水中铬的回收处理········································错误!未定义书签。2.2.1铬酸盐沉淀法·················································错误!未定义书签。2.2.2以氢氧化铬或三氧化二铬形式回收··················错误!未定义书签。2.3.3阴离子交换法················································错误!未定义书签。2.3含其他重金属离子的废水处理··································错误!未定义书签。2.4酸碱废水处理·························································错误!未定义书签。3我国治理电镀废水的发展历程···································································154电镀废水发展前景··················································································155结论···································································································16参考文献···································································································17111引言1.1电镀与电镀废水1.1.1电镀废水的概况电镀是将金属通过电解方法镀到制品表面的过程。电镀是当今全球三大污染工业之一，随着科学技术的发展电镀工业的规模亦发展，排放的废水量越来越大，据不完全统计，1999年全国工业和城市生活污水排放总量为401亿m3，电镀厂排放出废水达40亿m3。由此可见，电镀废水的排放量约占工业废水排放量的10%。目前，绝大多数电镀分散在各有关企业，例如：自行车厂、家具厂、汽车厂等等，都附设有电镀车间，实为厂多面广，较为分散，大多数直接排放，给环境造成严重污染。为了解决这一问题，在一个城市或一个地区集中建立电镀工业，使电镀工业由分散转向集中，则有利于电镀废水的处理。电镀废水主要来源有：(1)镀件清洗废水;(2)电镀废液;(3)其他废水(包括冲刷车间、刷洗地板以及通风设备冷凝水和由于镀槽渗漏或者操作管理不当造成跑、冒、滴、漏的各种槽液和排水);(4)设备冷却水。其废水的水质、水量与电镀生产的工艺条件、生产负荷、操作管理以及用水方式等因素有关，其成分复杂，水质变化较大，其中含有铬、铜、镍、镉、锌等重金属离子和氰化物等，具有毒性，有的属“三致”物质，对人类危害极大。如随意排放或处理不当，会造成严重的环境污染。为此，对电镀废水进行有效处理已成为每个生产企业的艰巨任务。电镀品种较多，主要有：镀铬、镀锌、镀铜、镀镍、镀银等，有金属电镀，也有塑料电镀。废水主要来自镀件镀前的酸、碱处理以及镀后的漂洗。镀件镀前的酸、碱处理液对各种电镀是相同的，但是，镀件的漂洗液的组成则完全不同，处理方法也完全不同，所以要把各种电镀按车间分开，使整体布局合理化，给电镀废水的处理集中提供好的基础。通过对该类废水的处理试验研究并进行工艺比较，确定了适合该废水水质水量变化特点的处理方法。即将各类废水单独收集，并进行必要的预处理，然后22再进行适当合并综合处理。该工艺技术已在多家电镀废水处理项目中得到成功应用。1.1.2电镀及电镀废水来源电镀是利用化学和电化学方法在金属和非金属表面进行装饰、防护及获得某些新的性质的一种工艺过程。电镀技术广泛应用于机器制造、轻工、电子等行业。电镀行业中，常用的镀种有镀镍、镀铜、镀铬、镀锌、镀镉、镀铅、镀银、镀金和镀锡。氰根（CN-）具有很好的络合性、表面活性，在某些电镀生产中被大量使用。镀铜、镀锌、镀铜锡合金、镀金及某些活化液、退渡液等，都可采用氰化物。铬主要用于镀铬、钝化和退镀等工艺。铜和镍等重金属也在电镀中应用较多。电镀车间有镀前表面处理、电镀处理和镀后处理三个工艺环节[1]。每个环节又包括若干工序，详见表1。表1电镀车间工艺工序环节镀前表面处理电镀处理镀后处理工序磨光抛光刷光滚光喷砂去油去锈浸蚀中和清洗电镀浸镀等抛光出光钝化着色干燥封闭去氢清洗等作用整平镀件并去除镀件上的污物，为电镀做准备镀上镀层清洗附着液，优化镀层质量电镀废水是电镀的以上环节、工序中产生的含有大量含金属离子、金属络合离子及清洗液的液体。电镀废水主要来源有：前处理除油酸洗工序，镀件的清洗水，废电镀液，跑、冒、滴、漏的各种槽液和排水，冲洗水及设备冷却水。331.1.3电镀废水的性质和危害1.1.3.1电镀废水的性质电镀废水的水质、水量与电镀生产的工艺条件、生产负荷、操作管理水平与用水方式等因素有关。电镀废水的成分非常复杂，除含氰(CN-)废水和酸碱废水外，重金属废水是电镀业潜在危害性极大的废水类别。根据重金属废水中所含重金属元素进行分类，一般可以分为含铬(Cr6+)废水、含镍(Ni)废水、含镉(Cd)废水、含铜(Cu)废水、含锌(Zn)废水、含金(Au)废水、含银(Ag)废水等。废水中含有多种高毒物质，危害性很大。另一方面，废水中许多成分又是宝贵的工业原料[2-3]。1.1.3.2电镀废水的危害1）含氰废水的危害氰化物是极毒物质，特别在酸性条件下，它变成剧毒的氢氰酸。人体对氰化钾的中毒致死剂量