综合电镀废水中重金属的协同与竞争去除机理研究
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摘 要
电镀废水是我国每年排放量最大的工业废水之一，属于典型难处理的有毒废
水，每年约 50%的废水不能达标排放。如果未处理完全的废水进入环境，将造成
深远影响。通过对江浙地区九家电镀厂的废水进行监测，大多数电镀废水中都含
有铜、镍、铬这三种重金属组份，它们的浓度随着工艺变化明显。
研究电镀废水单一重金属沉淀规律时发现，重金属随着 pH 变化呈现出四种
形态：离子态重金属（水合态重金属），水溶氢氧化物，胶态氢氧化物，絮状氢
氧化物沉淀。依据铜、镍、铬三种重金属的原子半径以及电负性特点，发现铜、
铬离子与氢氧根的结合能力比镍离子强，进一步研究复合重金属沉淀规律证明了
铜铬离子间存在协同作用，镍离子与铜离子、铬离子间存在竞争作用。这是由于
当重金属离子共存时，不同重金属离子在不同形态时与氢氧根结合能力不同，加
快或减慢了其他重金属离子与氢氧根的结合速度，导致重金属离子间的协同竞争
现象。
研究电镀废水重金属复合污染物去除规律时，首先以一种典型综合电镀废水
为研究对象，分别讨论了氧化还原反应、不同外投材料、碱类的选择及投加方式
和混凝剂对综合电镀废水处理过程中重金属的协同竞争作用；在此基础上开发了
一种基于铁镁/锰尾矿石投加的电镀废水处理新工艺，以七种实际电镀废水为试
验对象，对其工艺及运行参数进行优化，探究了重金属间以及重金属与其他组份
间的协同竞争作用，得到以下结论：
（1）电镀废水中长链有机物、氨氮类污染物易与重金属离子络合，导致出
水重金属浓度偏高；废水中磷酸类污染物物化处理后对出水重金属浓度影响不
大；
（2）选择焦亚硫酸钠为六价铬还原剂具有污泥产量低、投加量少、毒性
低、对重金属离子无明显抑制作用的优点；氢氧化钙作为增重剂能加速小分子重
金属颗粒沉淀，并能中和溶液中多余的焦亚，减少焦亚对重金属沉淀的抑制作
用；选择三氯化铁为混凝剂须严格控制其投加量，避免 pH 下降过多引起重金属
沉淀再溶解；
（3）采用含铁镁/锰尾矿石能中和过量焦亚硫酸钠，经水解后产生的氢氧化
镁能将重金属离子吸附在尾矿石表面，对铜镍离子去除效果明显，能有效降低出
水重金属浓度；尾矿石经酸化后能扩大其内部孔隙结构，加强对重金属的协同去
除能力，减弱对六价铬还原的抑制作用；
（4）适当投加双氧水能有效氧化长链有机物，促进尾矿石对 CODCr 的去除
效果，减少尾矿石投加量；合理的曝气时间能提高废水中溶液氧浓度，加强尾矿
石对废水中有机物的催化氧化作用；
（5）综合电镀废水推荐处理工艺为：投加双氧水/焦亚硫酸钠反应完全后，
外投铁镁尾矿石/铁锰尾矿石，同时开始曝气，曝气结束后投加混合碱沉淀后出
水，依据出水水质决定是否投加纳米铁材料；
（6）优化后的投加量为：双氧水 0.5-1.0mg / mg CODCr；焦亚硫酸钠 0.15-
0.25 mg / mg T-Cr；尾矿 1-4 mg / mL 废水；曝气时间 0.5-2.0h；氢氧化钠：氢氧
化钙比例为 2:1-1:1，一沉 pH 值7.0-8.0，二沉 pH 值10.5-12.0。
关键词：电镀废水 重金属 协同/竞争去除
ABSTRACT
Electroplating wastewater is one of the largest industrial wastewater emissions every
year in China. It belongs to the typical toxic wastewater treatment. About 50% of the
wastewater cannot reach the discharge standard. If the wastewater cannot be treated
completely into the environment, it will have a profound impact. By monitoring the nine
kinds of electroplating wastewater in Jiangsu and Zhejiang electroplate factories, the
majority of electroplating wastewater contained copper, nickel and chromium, three kinds
of heavy metal component, and their concentration change obviously with the process.
The research of single heavy metal precipitation in electroplating wastewater was
found that heavy metal appeared in four forms with the variation of pH: ionic heavy metal
(water soluble heavy metals), water soluble hydroxide, colloidal hydroxide and
flocculation hydroxide precipitation. On the basis of the atomic radius and
electronegativity of copper, nickel and chromium, the combination of copper and
hydroxyl, chromium ion and hydroxyl was stronger than that of nickel. The study of
comprehensive heavy metals precipitation was found the synergistic effect between
copper and chromium ions, and competitive effect between nickel and copper, and
chromium ions. This is due to the coexistence of different heavy metal ions in water,
different heavy metal ions in different forms had different binding capacity with hydroxyl,
which speed up or slow down the combine speed of other metals ions and hydroxyl,
resulting in the phenomenon of synergistic and competitive effect between heavy metal
ions.
When the removal role of heavy metals in composite electroplating wastewater was
studied, firstly, using a typical comprehensive electroplating wastewater as the research
object to discuss the influence of redox reaction, different investment materials, selection
and dosing method of coagulant and alkali on the synergetic and competitive effect
between heavy metal ions during comprehensive electroplating wastewater treatment. On
the basis of this role, a new electroplating wastewater treatment process of magnesium
iron / manganese tailings dosage was based on. Then the process and operation
parameters in treating seven actual electroplating wastewater were optimized to study the
synergistic and competitive effect between heavy metal ions and heavy metals to other
components. The main conclusions can be summarized as the following:
(1) Long chain organic substance, ammonia nitrogen pollutant in the electroplating
wastewater had the complexation reaction with heavy metal ions easily, leading to high
effluent concentration of heavy metals. Phosphate pollutants had little effect on the
effluent after wastewater treatment;
(2) Using sodium metabisulfite as reducing agent of hexavalent chromium had the
advantages of low sludge yield, less dosage, low toxicity, no significant inhibitory effect
on heavy metal ions; Calcium hydroxide as a weighting agent could accelerate the small
molecular metal particle precipitation, neutralize the excess sodium metabisulfite in the
solution and reduce the inhibitory effect of sodium metabisulfite on precipitation of heavy
metals; In order to avoid pH value decline too much to cause the heavy metal precipitation
dissolution, dosage of ferric chloride must be controlled strictly;
(3) Magnesium iron / manganese tailings could neutralize excess adding pyrosulfite.
Magnesium hydroxide, produced by tailings hydrolysis, adsorbed heavy metal ions on
the surface of tailings, having obvious effect on copper and nickel ions and reducing the
outflow concentration of heavy metals effectively; Tailings by acidification could expand
its internal space structure, strengthen the coordination ability of heavy metals, and
weaken the inhibitory effect of the reduction of hexavalent chromium;
(4) Adequate dosage of hydrogen peroxide could oxidate long chain organic matter
effectively. Tailings removal efficiency of CODCr was promoted. The dosage of tailings
was reduced obviously; Reasonable aeration time could improve the oxygen
concentration in the wastewater. Catalytic oxidation of tailings to organic matter in
wastewater was enhanced;
(5) The final process of comprehensive electroplating wastewater treatment was:
after adding hydrogen peroxide / pyrosulfite first, addition of magnesium iron /
manganese tailings and aeration at the same time , end of the aeration and using mixed
alkali to adjust pH value, after precipitation, according to the effluent quality to decide
whether the addition of coagulant or not.
(6) The optimized dosage was: hydrogen peroxide 0.5-1.0mg / mg CODCr;
pyrosulfite 0.15-0.25 mg / mg T-Cr; tailings 1-4 mg / mL electroplating wastewater; the
mixing ratio of sodium hydroxide and calcium hydroxide: 2:1-1:1, the pH value of the
first time precipitation 7.0-8.0, the pH value of the second time precipitation 10.5-12.0.
Key Word: electroplating wastewater, heavy metals, synergistic /
competitive removal
目 录
中文摘要
ABSTRACT
第一章 绪论 ......................................................... 1
1.1 综合电镀废水的来源 ............................................. 1
1.2 综合电镀废水的特性 ............................................. 2
1.3 综合电镀废水预处理 ............................................. 4
1.4 综合电镀废水的危害 ............................................. 5
1.5 重金属的协同竞争去除规律研究 ................................... 8
1.6 研究目的和意义 ................................................ 10
1.7 研究内容 ...................................................... 10
第二章 实验材料、设备及研究方法 .................................... 12
2.1 实验材料与主要试剂 ............................................ 12
2.2 实验主要仪器及设备 ............................................ 12
2.3 试验方法 ...................................................... 13
2.3.1 水样预处理 ................................................ 13
2.3.2 AAS 法检测重金属离子 ...................................... 13
2.3.3 氨氮浓度检测 .............................................. 15
2.3.4 总磷浓度检测 .............................................. 17
2.3.5 CODCr 浓度监测 .............................................. 18
2.3.6 模拟废水的配置 ............................................ 18
2.4 综合电镀废水检测 .............................................. 18
第三章 重金属离子的协同竞争去除机制 ................................ 23
3.1 重金属离子形态特征分析 ........................................ 23
3.1.1 铜离子形态规律 ............................................ 24
3.1.2 镍离子形态规律 ............................................ 24
3.1.3 铬离子形态规律 ............................................ 24
3.2 重金属协同竞争去除理论机理 .................................... 25
3.3 重金属离子间的协同竞争去除试验 ................................ 27
3.3.1 铜离子的协同竞争去除 ...................................... 27
3.3.2 镍离子的协同竞争去除 ...................................... 28
3.3.3 铬离子的协同竞争去除 ...................................... 31
3.4 本章小结 ...................................................... 32
第四章 综合电镀废水处理单元中的协同竞争作用研究 .................... 34
4.1 氧化还原法对重金属的协同竞争作用影响 .......................... 35
4.1.1 不同还原剂对协同竞争作用影响 .............................. 35
4.1.2 不同氧化剂对协同竞争作用影响 .............................. 36
4.2 沉淀法对重金属的协同竞争作用影响 .............................. 37
4.2.1 碱种类对协同竞争作用的影响 ................................ 37
4.2.2 反应体积对协同竞争作用的影响 .............................. 38
4.2.3 碱不同投加方式对协同竞争作用的影响 ........................ 39
4.3 混凝沉淀对重金属协同竞争作用的影响 ............................ 40
4.4 其他污染物组份对重金属协同竞争作用的影响 ...................... 41
4.5 本章小节 ...................................................... 42
第五章 基于重金属协同竞争作用的综合电镀废水处理工艺优化及案例分析 .. 43
5.1 浙江某电镀厂综合电镀废水处理 .................................. 43
5.1.1 外投铁氰化钾对重金属协同竞争作用的影响 .................... 43
5.1.2 焦亚不同投加方式对重金属协同竞争作用的影响 ................ 44
5.1.3 不同搅拌方式对重金属协同竞争作用的影响 .................... 45
5.1.4 外投铁镁尾矿石对重金属协同竞争作用的影响 .................. 47
5.1.5 纳米铁材料对重金属协同竞争作用的影响 ...................... 48
5.2 江苏某大型电镀厂电镀废水处理 .................................. 49
5.2.1 综合废水处理优化 .......................................... 50
5.2.2 含镍水工艺优化 ............................................ 54
5.2.3 含铬水工艺优化 ............................................ 56
5.3 浙江某大型电镀厂废水处理 ...................................... 59
5.3.1 综合水处理 ................................................ 59
5.3.2 含铬及混排废水处理效果 .................................... 63
5.4 本章小结 ...................................................... 64
第六章 结论与建议 .................................................. 66
6.1 结论 .......................................................... 66
6.2 建议 .......................................................... 67
参考文献 ........................................................... 68
在读期间公开发表的论文和承担科研项目及取得成果 ..................... 75
致谢 ............................................................... 76
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作者：侯斌
分类：高等教育资料
价格：15积分
属性：81 页
大小：4.36MB
格式：PDF
时间：2025-01-09
