Integrated electroplating treatment method for waste water

A technology for electroplating wastewater and wastewater treatment is applied in the field of recycling precious metal resources, which can solve the problems of secondary pollution of sludge, inability to recycle precious metals, and inability to reuse effluent, and achieve the effect of reducing production costs.

Inactive Publication Date: 2008-08-06
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the disadvantages of the traditional chemical method that the effluent cannot be reused, the secondary pollution of the sludge is serious, and the precious metal cannot be recovered, the present invention provides a new process for the treatment of electroplating wastewater, which can not only make the electroplating wastewater treated The effluent meets the reuse water standard, and some indicators are better than the tap water standard, and the precious metal resources in the original wastewater can be recovered

Method used

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  • Integrated electroplating treatment method for waste water
  • Integrated electroplating treatment method for waste water
  • Integrated electroplating treatment method for waste water

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Example 1: An industrial park in Shenzhen discharges 3,000 tons of comprehensive electroplating wastewater every day. Influent water quality index:

[0025] Table 1 Sewage water quality of three kinds of sewage Unit: mg / L

[0026]

[0027] Use the method shown in Figure 1:

[0028] 1. Pretreatment of chromium-containing wastewater

[0029] The chromium-containing wastewater enters the pH value adjustment tank, and then enters the chromium reduction tank through the lifting pump. A set of pH automatic control system and ORP automatic control system are installed in the reduction tank. The pH control system automatically controls the amount of acid added to adjust the wastewater. The pH is 2.5, and at the same time, the addition of reducing agent is controlled by the ORP automatic control system, so that the ORP value of the wastewater is 250mV. Add NaOH to the reduced chromium-containing wastewater to control the pH value to 7.5, so that the trivalent chromium will...

Embodiment 2

[0044] Example 2: Treatment and reuse of comprehensive electroplating wastewater in an "Electroplating City" (daily treatment capacity: 2,000 tons)

[0045] Table 1 Sewage Water Quality of Three Kinds of Sewage Unit: mg / L

[0046]

[0047] 1. Pretreatment of chromium-containing wastewater

[0048] The pH of the wastewater was adjusted to 2.7, and the ORP value of the wastewater reached 270mV by adding a reducing agent. NaOH was added to the reduced chromium-containing wastewater to control the pH to 7.8. The rest of the process steps were the same as in Example 1.

[0049] 2. Pretreatment of cyanide-containing wastewater

[0050] The pH of the wastewater is adjusted to 11, the ORP value is 330mV; the pH of the wastewater is adjusted to 7.7 in the secondary oxidation tank, the ORP value is 640mV, and the hydraulic retention time is 1 hour. All the other processing steps and reaction conditions are with embodiment 1.

[0051] 3. Comprehensive waste water

[0052] (1) Coag...

Embodiment 3

[0062] Example 3: Treatment and reuse of electroplating comprehensive wastewater in an electroplating enterprise (daily processing capacity: 2500 tons)

[0063] Table 1 Sewage Water Quality of Three Kinds of Sewage Unit: mg / L

[0064]

[0065] 1. Pretreatment of chromium-containing wastewater

[0066] Adjust the pH of the wastewater to 3.0, and make the ORP value of the wastewater reach 300mV by adding a reducing agent. Add NaOH to the reduced chromium-containing wastewater to control the pH value to 8.0, and the rest of the process steps are the same as in Example 1.

[0067] 2. Pretreatment of cyanide-containing wastewater

[0068] Adjust the pH of the wastewater to 11.8, the ORP value is 320mV; adjust the pH of the wastewater to 8.0 in the secondary oxidation tank, the ORP value is 650mV, and the hydraulic retention time is 1 hour. All the other processing steps and reaction conditions are with embodiment 1.

[0069] 3. Comprehensive waste water

[0070] (1) Coagula...

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Abstract

The invention relates to a method for treating comprehensive galvanization wastewater, particularly relating to a technique reclaiming resources of precious metal and recycly utilizing treated and comprehensively discharged galvanization wastewater. The method for treating the galvanization wastewater in the invention is characterized in that the following steps are included: (1) treating the wastewater containing chromium; (2) treating the wastewater containing cyanogen; (3) mixing and treating clear liquid obtained during treating the wastewater containing chromium in step (1) and the wastewater containing the cyanogen during treating the wastewater containing the cyanogen in step (2); (4) leading the clear liquid obtained during mixing and treating in step (3) into a reclaiming clean water pond; (5) leading the concentrated solution in step (4) into a comprehensive regulating pond of wastewater. Through treated by the technique of the method for treating comprehensive galvanization wastewater, each index of water quality of obtained water can reach or exceed the Drinking Water Sanitary Standard (GB5749-2006); the water can be reused in galvanization workshops; the water production rate of the reused water can reach over 80 percent; useful metal ions can be reclaimed; the target of environment protection can be met; benefits can be generated at the same time; the production cost can be reduced.

Description

technical field [0001] The invention relates to a comprehensive electroplating wastewater treatment method, in particular to a process for recycling the comprehensively discharged electroplating wastewater after treatment and recovering precious metal resources. Background technique [0002] In the electroplating industry, according to the different plating types and electroplating processes, the wastewater generated during the production process mainly includes oily wastewater, wastewater containing different complex refractory substances, acid-base copper-nickel wastewater, chromium-containing wastewater and cyanide-containing wastewater, etc. several categories. Especially for comprehensive enterprise industrial parks such as "Electroplating City", the water quality of electroplating wastewater is complex and the composition is difficult to control. Among them, the most polluting factors that exceed the standard are heavy metals such as copper ions, chromium ions, nickel...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C02F1/58C02F1/24C02F1/52C02F9/14C02F101/18C02F101/22C02F103/16
Inventor 孙宝盛张斌齐庚申朱文亭刘景允张海丰刘世德
Owner TIANJIN UNIV
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