目 录
摘 要 ····································································································· 错误！未定义书签。 Abstract ································································································ 错误！未定义书签。
1 引言····································································································································· 1
1.1 电镀与电镀废水 ········································································································ 1
1.1.1 电镀及电镀废水来源 ····················································································· 1 1.1.2 电镀废水的性质和危害 ················································································· 1 1.2 我国电镀污染现状 ···································································································· 3 1.3 电镀废水处理技术综述 ···························································································· 4
1.3.1 物理方法 ········································································································· 4 1.3.2 化学方法 ········································································································· 4 1.3.3 物理化学方法 ································································································· 6 1.3.4 生物处理方法 ································································································· 8 1.4 设计的主要内容和范围 ···························································································· 9
1.4.1 设计的主要内容 ····························································································· 9 1.4.2 设计范围 ······································································································· 10
2 设计说明书 ······················································································································ 11
2.1 工程概况 ·················································································································· 11 2.2 设计依据和设计原则 ······························································································ 11
2.2.1 设计依据 ······································································································· 11 2.2.2 设计原则 ······································································································· 12 2.3 设计水质水量、排放标准和出路 ········································································· 12
2.3.1 水质水量 ······································································································· 12 2.3.2 排放标准 ······································································································· 13 2.3.3 排放出路 ······································································································· 13 2.4 处理工艺的选择及说明 ·························································································· 13
2.4.1 水质水量特性分析 ······················································································· 13 2.4.2 工艺流程的选择 ··························································································· 13 2.4.3 工艺流程说明 ······························································································· 17
2.5 主要构筑物的设计及设备选型说明 ····································································· 19
2.5.1 含氰废水处理系统 ······················································································· 19 2.5.2 含铬废水处理系统 ······················································································· 20 2.5.3 综合废水处理系统 ······················································································· 20 2.5.4 药剂投配系统 ······························································································· 21 2.6 构筑物和设备材料一览表······················································································ 23
2.6.1 构筑物一览表 ······························································································· 23 2.6.2 设备材料一览表 ··························································································· 24 2.7 平面布置和高程布置 ······························································································ 26
2.7.1 平面布置 ······································································································· 26 2.7.2 高程布置 ······································································································· 26 2.8 土建、电气和自动控制介绍·················································································· 26 2.9 二次污染防治 ·········································································································· 27 2.10 人员配备 ················································································································ 27 3 设计计算书 ······················································································································ 28
3.1 含氰废水处理系统计算 ·························································································· 28
3.1.1 单体计算 ······································································································· 28 3.1.2 投药量计算 ··································································································· 28 3.2 含铬废水处理系统计算 ·························································································· 30
3.2.1 单体计算 ······································································································· 30 3.2.2 投药量计算 ··································································································· 30 3.3 综合废水处理系统计算 ·························································································· 31
3.3.1 单体计算 ······································································································· 31 3.3.2 投药量计算 ··································································································· 33 3.4 药剂投配系统计算 ·································································································· 35
3.4.1 酸（H2SO4）································································································ 35 3.4.2 碱（NaOH）································································································ 35 3.4.3 二氧化氯（ClO2） ······················································································ 35 3.4.4 焦亚硫酸钠（Na2S2O5） ··········································································· 35 3.4.5 混凝絮凝剂（PAC/PAM）········································································· 36 3.5 高程计算 ·················································································································· 36 4 工程概预算 ······················································································································ 37
4.1 投资估算 ·················································································································· 37
4.1.1 直接费············································································································ 37 4.1.2 间接费············································································································ 40 4.1.3 第二部分费用 ······························································································· 40 4.1.4 工程预备费 ··································································································· 40 4.1.5 工程总投资 ··································································································· 40 4.2 运行费用 ·················································································································· 41
4.2.1 动力费············································································································ 41 4.2.2 药剂费············································································································ 41 4.2.3 工资及福利费 ······························································································· 41 4.2.4 总资产折旧费 ······························································································· 41 4.2.5 其他费用 ······································································································· 41 4.3 单位废水处理成本 ·································································································· 41 5 效益分析 ·························································································································· 42
致 谢 ····································································································································· 43 参考文献 ································································································································· 44 附 录 ····································································································································· 46
1 引言
1.1 电镀与电镀废水
1.1.1 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 工序 作用 镀前表面处理 磨光 抛光 刷光 滚光喷砂 去油 去锈浸蚀 中和 清洗 整平镀件并去除镀件上的污物，为电镀做准备 电镀处理 电镀 浸镀等 镀上镀层 镀后处理 抛光 出光 钝化 着色 干燥 封闭 去氢 清洗等 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。
1.1.2 电镀废水的性质和危害
1.1.2.1 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]。 1.1.2.2 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为0.25g（纯净氰化钾为0.15g）。很低浓度的氢氰酸（4~5）×10-6，0.05mg/L，会引起很短时间的头疼、心率不齐。在高浓度（9×10-6，0.1 mg/L）时能立即致人死亡。
对鱼类和其他水生物的危害为（以游离CN-计）：浓度为0.04~0.1mg/dm3就能使鱼类致死。此外，含氰废水作为农灌水时会使农作物减产。 2）含铬废水的危害
铬有三价（Cr3+）和六价（Cr6+）之分。六价铬对人体的危害，因进入途径不同，中毒表现也不同。（1）对人体皮肤的损害：六价铬化合物对皮肤有刺激和过敏作用。六价铬经过切口和擦伤处进入皮肤，会因腐蚀作用而引起铬溃疡（又称铬疮）。（2）对呼吸系统的损害：六价铬对呼吸系统的损害，主要是鼻中隔膜穿孔、咽喉炎和肺炎。（3）对内脏的损害：六价铬经消化道侵入，会造成味觉和嗅觉减退，以至消失。剂量小时也会腐蚀内脏；引起肠胃功能降低，出现胃痛，甚至肠胃道溃疡，对肝脏还可能造成不良影响。
三价铬是生物所必需的微量元素。通过动物试验发现三价铬有激活胰岛素的作用，还可以增加对葡萄糖的利用。实验证明，六价铬的毒性比三价铬高100倍。 3）含锌废水的危害
锌是人体必需的微量元素之一，正常人每天从食物中摄取锌10~15mg。人体缺锌会出现不少不良症状，误食可溶性锌盐对消化道黏膜有腐蚀作用。过量的锌会引起急性肠胃炎症状，如恶心、呕吐、腹痛、腹泻，偶尔腹部绞痛，同时伴有头晕、周身乏力。误食氯化锌会引起腹膜炎，导致休克而死亡。 4）含铜废水的危害
铜是生命所必须的微量元素之一，但过量的铜对人体和动植物都有害。对于人来说，过量的接触铜化合物会导致皮炎和湿疹；水中铜含量过量时，会抑制水体自净；铜可以在土壤中富集，污染粮食籽粒；铜对水生生物的毒性也很大。 5）含镍废水的危害