Treatment method of cyanide-containing electroplating comprehensive wastewater

A technology that integrates waste water and treatment methods. It is applied in metallurgical waste water treatment, special compound water treatment, neutralized water/sewage treatment, etc. It can solve problems such as poor sulfur cyanide removal effect, consumption of sodium hypochlorite, and increased treatment costs. Achieve the effect of low infrastructure cost, low operating cost and high processing efficiency

Active Publication Date: 2015-03-11
HUAQIAO UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method also has disadvantages. Sodium pyrosulfite is reductive and easily decomposed into sodium sulfite. If the aeration time of the added sodium pyrosulfite is insufficient, some sodium pyrosulfite will enter the next step, which will consume sodium hypochlorite and greatly increase cost of treatment; in addition, this method is not very effective for the removal of thiocyanate

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] (1) Take cyanide ≤ 600mg / L, copper ion ≤ 800mg / L, nickel ion ≤ 400mg / L comprehensive cyanide-containing electroplating wastewater, add liquid caustic soda to adjust the pH to 8.2, add cationic PAM to a final concentration of 0.1‰ , left to settle, and the supernatant was analyzed to determine the concentration of cyanide, as follows: the concentration of cyanide was 256.84 mg / L, the concentration of copper ions was 174.98 mg / L, and the concentration of nickel ions was 48.60 mg / L;

[0029] (2) adding liquid caustic soda to the supernatant obtained in step (1) to adjust the pH to 11.20;

[0030] (3) Add sodium hypochlorite solution to the supernatant after pH adjustment in step (2), stir and react with a speed of 200rpm for 30min, after the reaction finishes, leave to settle and get the supernatant, the dosage of the sodium hypochlorite solution makes this time The mol ratio of the sodium hypochlorite added and the cyanide of the supernatant in step (1) reaches 1.2:1;

...

Embodiment 2

[0035] (1) Take cyanide ≤ 600mg / L, copper ions ≤ 800mg / L, nickel ions ≤ 400mg / L comprehensive cyanide-containing electroplating wastewater, add liquid caustic soda to adjust the pH to 11.7, and add cationic PAM to a final concentration of 0.8‰ , left to settle, and the supernatant was analyzed to determine the concentration of cyanide, as follows: the concentration of cyanide was 187.52 mg / L, the concentration of copper ions was 152.38 mg / L, and the concentration of nickel ions was 11.02 mg / L;

[0036] (2) adding liquid caustic soda to the supernatant obtained in step (1) to adjust the pH to 11.22;

[0037] (3) Add sodium hypochlorite solution to the supernatant after adjusting the pH in step (2), stir and react with 200rpm speed for 35min, after the reaction finishes, leave to settle and get the supernatant, the dosage of described sodium hypochlorite makes this time The mol ratio of the sodium hypochlorite added and the cyanide of the supernatant in step (1) reaches 1.5:1; ...

Embodiment 3

[0042] (1) Take cyanide ≤ 600mg / L, copper ions ≤ 800mg / L, nickel ions ≤ 400mg / L electroplating cyanide comprehensive wastewater, add liquid caustic soda to adjust the pH to 10.0, add cationic PAM to a final concentration of 0.1‰ , left to settle, and the supernatant was analyzed to determine the concentration of cyanide, as follows: the concentration of cyanide was 339.38 mg / L, the concentration of copper ions was 169.08 mg / L, and the concentration of nickel ions was 74.03 mg / L;

[0043] (2) adding liquid caustic soda to the supernatant obtained in step (1) to adjust the pH to 11.25;

[0044] (3) Add sodium hypochlorite solution to the supernatant after pH adjustment in step (2), stir and react with a speed of 200rpm for 30min, after the reaction finishes, leave to settle and get the supernatant, the dosage of the sodium hypochlorite solution makes this time The mol ratio of the sodium hypochlorite added and the cyanide of the supernatant in step (1) reaches 2.0:1;

[0045] (...

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PUM

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Abstract

The invention discloses a treatment method of cyanide-containing electroplating comprehensive wastewater, which comprises the following steps: (1) taking the cyanide-containing electroplating comprehensive wastewater, adding alkaline liquor, regulating pH (potential of hydrogen) to 8.0-12.0, adding cationic PAM (polyacrylamide), standing for precipitation, taking a supernate for analysis to determine the cyanide concentration, (2) adding the alkaline liquor to the supernate to regulate the pH to 10-14, (3) adding a sodium hypochlorite solution, stirring for reaction, standing for precipitation after the reaction, and taking a supernate, (4) adding concentrated sulfuric acid, regulate the pH to 6.5-7.0, (5) adding the sodium hypochlorite solution, stirring for reaction to form reaction liquid, and (6) adding a ferrate solution into the reaction liquid, stirring, standing for reaction, and filtering to obtain treated wastewater. The method solves the problems that a thiocyanogen compound cannot be removed by a two-step alkaline chlorination method and a sodium pyrosulfite air oxidation-sodium hypochlorite combined method, and the water becomes black when sodium hypochlorite is fed excessively during treatment.

Description

technical field [0001] The invention belongs to the technical field of wastewater treatment, and in particular relates to a treatment method for electroplating comprehensive cyanide-containing wastewater. Background technique [0002] Electroplating is one of the three major industrial pollutions in the world today. The large amount of cyanide used in the electroplating process makes the electroplating wastewater very harmful. Not only that, the electroplating wastewater often contains heavy metal ions such as chromium, nickel, copper, and lead, as well as acids, alkalis, and a large amount of organic matter. Cyanide (especially free cyanide) is a highly toxic substance, which will combine with ferricytochrome oxidase in the human body, hinder cell respiration and cause suffocation and death; discharge of cyanide-containing wastewater into the natural environment will cause serious Environmental pollution, heavy metals will pollute the soil and cause the accumulation of hea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C02F103/16
CPCC02F1/003C02F1/56C02F1/66C02F1/72C02F1/76C02F9/00C02F2103/16C02F2301/00C02F2303/185C02F2303/22C02F2305/023
Inventor 苑宝玲朱铭桥黄华山何强周真明
Owner HUAQIAO UNIVERSITY
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