Exploration on Removal of Zinc Ion in Salt Separation Crystallization Residue of Coal Chemical Industry Exploration on Removal of Zinc Ion in Salt Separation Crystallization Residue of Coal Chemical Industry
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摘要: 煤化工高盐废水零排放过程中会产生少量浓缩残液,盐含量高达20% ~ 30%,含有一定量的锌离子为代表的重金属离子,属于危废,处理成本高。本研究开展高盐体系锌离子赋存状态模拟计算,得到Zn的各种形式占比随pH值、温度、NaCl盐浓度的变化趋势,并开展了以Na2S为沉淀剂对实际高盐有机废水体系深度脱除探索,优化了搅拌速度、初始pH值、硫化钠投加量等工艺条件,为煤化工高盐废水中锌离子的脱除提供理论指导与技术支持。
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关键词:
- 煤化工 /
- 高盐废水 /
- 重金属 /
- Visual MINTEQ
Abstract: In the process of zero discharge of high-salt wastewater from coal chemical industry, a small amount of concentrated residual liquid will be produced, the salt content is as high as 20% ~ 30%, and it contains a certain amount of heavy metal ions represented by zinc ions. It is hazardous waste and has high treatment costs. This research carried out the simulation calculation of the occurrence state of zinc ions in the high-salt system, obtained the variation trend of the proportion of various forms of Zn with the pH value, temperature, and NaCl salt concentration, and carried out the actual high-salt organic wastewater system with Na2S as the precipitant. In-depth exploration of removal, optimization of the stirring speed, initial pH value, sodium sulfide dosage and other process conditions, provide theoretical guidance and technical support for the removal of zinc ions in coal chemical high-salt wastewater.-
Key words:
- coal chemical industry /
- high-salt wastewater /
- heavy metals /
- Visual MINTEQ
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表 1 锌溶液体系的沉淀物SI值(wNaCl=0)
Table 1. The SI value of the precipitate in the zinc solution system(wNaCl=0)
Mineral SI value pH=5 pH=6 pH=7 pH=8 pH=9 Bianchite −3.254 −3.254 −3.255 −3.283 −3.935 Goslarite −3.008 −3.008 −3.009 −3.037 −3.689 Zincite −3.725 −1.725 0.273 2.231 3.438 Zincosite −8.946 −8.946 −8.948 −8.976 −9.628 Zn(OH)2 (am) −4.969 −2.969 −0.972 0.987 2.194 Zn(OH)2 (beta) −4.249 −2.249 −0.252 1.707 2.914 Zn(OH)2 (delta) −4.339 −2.339 −0.342 1.617 2.824 Zn(OH)2 (epsilon) −4.029 −2.029 −0.032 1.927 3.134 Zn(OH)2 (gamma) −4.229 −2.229 −0.232 1.727 2.934 Zn2(OH)2SO4 (s) −5.012 −3.012 −1.016 0.914 1.469 Zn3O(SO4)2 (s) −21.442 −19.442 −17.447 −15.545 −15.642 Zn4(OH)6SO4 (s) −10.902 −4.903 1.089 6.935 9.904 ZnSO4∶1H2O (s) −4.379 −4.379 −4.381 −4.409 −5.061 表 2 锌溶液体系的沉淀物SI值(wNaCl=25%)
Table 2. The SI value of the precipitate in the zinc solution system(wNaCl=25%)
Mineral SI value pH=5 pH=6 pH=7 pH=8 pH=9 Bianchite −9.533 −9.533 −9.533 −9.533 −9.535 Goslarite −9.615 −9.615 −9.615 −9.615 −9.617 Halite −0.551 −0.551 −0.551 −0.551 −0.551 Mirabilite −5.101 −5.101 −5.101 −5.101 −5.101 Thenardite −3.258 −3.257 −3.257 −3.257 −3.257 Zincite −6.952 −4.952 −2.952 −0.952 1.046 Zincosite −13.26 −13.26 −13.26 −13.26 −13.263 Zn(OH)2 (am) −8.524 −6.524 −4.524 −2.524 −0.526 Zn(OH)2 (beta) −7.804 −5.804 −3.804 −1.804 0.194 Zn(OH)2 (delta) −7.894 −5.894 −3.894 −1.894 0.104 Zn(OH)2 (epsilon) −7.584 −5.584 −3.584 −1.584 0.414 Zn(OH)2 (gamma) −7.784 −5.784 −3.784 −1.784 0.214 Zn2(OH)2SO4 (s) −12.881 −10.881 −8.881 −6.881 −4.885 Zn2(OH)3Cl (s) −11.465 −8.465 −5.465 −2.465 0.531 Zn3O(SO4)2 (s) −33.297 −31.297 −29.297 −27.297 −25.304 Zn4(OH)6SO4 (s) −25.881 −19.881 −13.881 −7.882 −1.890 Zn5(OH)8Cl2 (s) −27.098 −19.098 −11.098 −3.098 4.892 ZnCl2 (s) −11.447 −11.447 −11.447 −11.447 −11.449 ZnSO4:1H2O (s) −9.021 −9.021 −9.021 −9.021 −9.023 表 3 实际废水样品水质分析
Table 3. Water quality analysis of experimental water
Project Result pH value 6.40 COD(mg/L) 887.10 TOC(mg/L) 248.00 NaCl(mg/L) 1.96×105 Electrical conductivity(ms/cm) 217.98 Ammonia nitrogen(mg/L) 1.15 Calcium hard(mg/L) 0.10 表 4 废水中有机物成分分析
Table 4. Type and content of organic matter in water sample
Number Residence time Organic matter Total/% 1 8.07 1,3,5, 7-tetraoxacycloctane 2.21 2 11.56 5-acetoxy-6 (1, 2-epoxypropyl) -5, 6-dihydropyrane-2-one 1.87 3 12.09 (E)-4, 4-dimethyl-2-pentene 0.75 4 12.18 Ethyl 2-methyl-2-formyl-4-pentenoate 0.37 5 12.44 (s) -1-nitroso-2-piperidinic acid 5.58 6 12.82 9-oxabicyclic [3.3.1] none-2-ol 3.26 7 13.32 Octadhydro-2,3' -difuran 5.66 8 13.76 4-methyl-3-ethyl-2-pentene 0.89 9 14.15 2-ethyl-1-dodecene 69.29 Note: This percentage is only the peak area percentage, and cannot be used as a percentage of content. It is for reference only. -
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