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A kind of arsenic-containing wastewater treatment method

A waste water treatment and waste water collection technology, applied in water/sewage multi-stage treatment, water/sludge/sewage treatment, chemical instruments and methods, etc., can solve the problems of large area of ​​facilities and failure to meet discharge standards, etc., to achieve Save application costs, improve the efficiency of drug use, and avoid unstable effects

Active Publication Date: 2021-11-09
CHINA ELECTRONICS INNOVATION ENVIRONMENTAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the process uses two-stage coagulation and sedimentation, and the facility occupies a large area; at the same time, due to the relatively high arsenic in the effluent after coagulation, it cannot meet the increasingly stringent discharge standards

Method used

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  • A kind of arsenic-containing wastewater treatment method

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Effect test

Embodiment 1

[0037] Example 1: Water quality of arsenic-containing wastewater from a gallium arsenide semiconductor enterprise: There are two different concentrations of arsenic-containing wastewater in this enterprise: (1) arsenic-containing acid-alkaline wastewater: pH 3~9.5, arsenic content in wastewater TAs<100mg / L , Suspended solids content in wastewater SS<10mg / L, discharge rate 120m3 / d; (2) Arsenic-containing grinding wastewater: pH 3~9.5, TAs<100mg / L, SS<300mg / L, discharge rate 120m3 / d. Two kinds of waste water are jointly collected to the regulating tank for post-processing. This embodiment includes the following steps:

[0038] The first step: adjust the pH of the collected arsenic-containing wastewater to 6.5~7.5, and the reaction time is 30 minutes; then add 10% sodium hypochlorite to maintain ORP>400mV, and the reaction time is 30 minutes;

[0039] Step 2: Add 20% ferric chloride, the flow rate is 60L / h, adjust the pH to 7.5~9.5, and coagulate for 30 minutes. Then enter the c...

Embodiment 2

[0044] Example 2: An LED semiconductor production enterprise, the high-concentration arsenic-containing wastewater quality of the enterprise is: design discharge rate 20 m3 / h, COD 10-150 mg / L, SS 0-400 mg / L, TAs 50-250 mg / L , TP 10-20 mg / L, pH 3-7. The process steps before transformation are as follows:

[0045] The first step: adjust the pH of the collected arsenic-containing wastewater to 6.5~7.5, and the reaction time is 30 minutes; then enter the oxidation tank, add 10% sodium hypochlorite to maintain ORP>400mV, the reaction time is 30 minutes, and the effluent enters the reaction tank;

[0046] The second step: add 20% ferric chloride to the reaction tank, the flow rate is 288L / h, the pH is adjusted to 7.5~9.5, the coagulation reaction is 60min, then PAM is added, the reaction is 30min, and enter the sedimentation tank. The hydraulic retention time of the sedimentation tank is 4.5h, the supernatant enters the relay tank, and the hydraulic retention time of the relay tank...

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Abstract

The invention provides an arsenic-containing wastewater treatment method, which has good arsenic removal effect and can meet increasingly strict arsenic discharge standards. It includes the following steps: 1. After the wastewater is collected, the pH is adjusted by adding acid and alkali agents, and the trivalent arsenic is oxidized to pentavalent arsenic by adding an oxidant; 2. The mixed solution obtained in step 1 is coagulated by adding iron salt Coagulation reaction and pH adjustment; 3. Pass the mixed solution obtained in step 2 into the concentration pool, which is added with arsenic removal agent, and remove insoluble particles through the tubular microfiltration membrane system; 4. Process to step 3 to obtain Add iron salt to the mixed solution, and further reduce the arsenic concentration through the catalytic arsenic removal tower; 5. Add a reducing agent to the mixed solution obtained in step 4 to make the oxidation-reduction potential ORP<300mV, and after adjusting the pH to 5~6, pass The arsenic removal resin or arsenic removal filter material is discharged after deep arsenic removal.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a method for treating arsenic-containing wastewater. Background technique [0002] The arsenic-containing wastewater in the semiconductor industry usually comes from two parts. One part comes from the chip production process, such as cleaning, stripping, etching, grinding and polishing, and chip cutting. , Phosphorus-containing wastewater. As a class I pollutant, the discharge of arsenic is strictly controlled, and it is required in Table 1 of the Comprehensive Wastewater Discharge Standard (GB8978-1996) that arsenic should be less than 0.5mg / L. "Electronic Industry Pollutant Discharge Standard" (Second Draft for Comment) requires arsenic <0.1mg / L in Table 2; in Shanghai "Semiconductor Industry Pollutant Discharge Standard" (DB31-2006) Table 1, the Class A standard is arsenic < 0.05mg / L; the special discharge standard is arsenic <0.05mg / L. However, the ca...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F9/04C02F101/10
Inventor 田宇鸣熊江磊陆晟星周笈董全宇
Owner CHINA ELECTRONICS INNOVATION ENVIRONMENTAL TECH CO LTD
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