Treatment process of EDTA type high-complexation heavy metal waste water

A treatment process and heavy metal technology, applied in water/sewage multi-stage treatment, water/sludge/sewage treatment, sludge treatment, etc., to achieve cost saving and obvious removal effect

Pending Publication Date: 2019-05-17
CHINA ELECTRONICS INNOVATION ENVIRONMENTAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although a relatively good removal effect can also be achieved, in actual engineering applications, due to the heterogeneous reaction, in large-scale applications, the effect is worse than that of the homogeneous reaction.

Method used

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  • Treatment process of EDTA type high-complexation heavy metal waste water

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Effect test

Embodiment 1

[0029] The quality of nickel-containing wastewater in a semiconductor factory: suspended solids (SS) 50-80mg / L, total nickel 20-25mg / L, total phosphorus 18-25mg / L, mainly EDTA-Ni. The waste water flow rate is 10t / h, and it runs for 10 hours per day. The implementation steps of this case are as follows:

[0030] Step 1: Adjust the temperature of the waste water to 35°C through the heat exchanger, adjust the pH to 3, the dosage of H2O2 (30%) is 4.0L / h, and the dosage of FeSO4 (20%) is 9.5L / h , the dosing amount of potassium persulfate (10%) is 8.5L / h, and the reaction time for breaking the network is 2.5h;

[0031] The second step: add NaHSO3 to adjust the ORP to 200mv; adjust the pH to 11, and react for 2.5h;

[0032] The third step: add polyacrylamide (0.1%), the dosing amount is 4.0L / h, stir slowly for 2.5h for flocculation;

[0033] The fourth step: Enter the sedimentation tank and settle for 3 hours. After precipitation, the total nickel content of the supernatant is <0...

Embodiment 2

[0035] The quality of nickel-containing wastewater: suspended solids (SS) is 40-100mg / L, and the content of EDTA-Ni is 10-20mg / L. The waste water flow rate is 10t / h, and it runs for 12 hours every day. The implementation steps of this case are as follows:

[0036] Step 1: Adjust the temperature of the waste water to 35°C through the heat exchanger, adjust the pH to 3, the dosage of H2O2 (30%) is 3.0L / h, and the dosage of FeSO4 (20%) is 8.0L / h , The dosage of potassium persulfate (10%) is 7.0L / h. Broken network reaction time is 2.0h;

[0037] The second step: add NaHSO3 (10wt.%) to carry out the reduction reaction; adjust the pH to 10, and react for 2.0h;

[0038] The third step: add polyacrylamide (0.1%), the dosing amount is 6.0L / h, stir slowly for 2.0h for flocculation;

[0039] The fourth step: enter the sedimentation tank and settle for 4 hours. After precipitation, the total nickel content of the supernatant is less than 0.1mg / L, and the SS is less than 5mg / L. After ...

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Abstract

The invention relates to a treatment process of EDTA type high-complexation heavy metal waste water. Through pH regulation, advanced oxidation breaking, alkaline addition precipitation reaction, flocculation reaction and still standing precipitation, the standard reaching discharging of high-complexation state nickel containing waste water is realized; potassium peroxodisulfate, hydrogen peroxide,ferrous sulfate and few Fe-Mn catalysts are simultaneously added into a system; on one hand, the Fenton effect is achieved for generating hydroxyl free radicals; on the other hand, ferrous ions can activate potassium peroxodisulfate; sulfate radical free radicals are generated; the simultaneous oxidation treatment on EDTA-Ni by two kinds of free radicals is realized. Compared with a traditional Fenton-like technology, a new process has the advantages that the removal rate on the EDTA-Ni is approximately 100 percent; by the technology, the standard reaching discharging of nickel can be realized directly through physicochemical treatment; the subsequent deep treatment of continuous resin is not needed; the operation cost is reduced.

Description

technical field [0001] The invention relates to a sewage treatment process, in particular to a treatment process for strongly complexed heavy metal wastewater. Background technique [0002] With the rapid development of the semiconductor industry, the generation of strongly complexed heavy metal wastewater has also increased. In the production process of electronic components, due to the use of different complexing agents (EDTA, DTPA, ethanolamine, citric acid, tartaric acid, etc., among which EDTA has strong complexation), a large number of stable heavy metal complexes are produced, which are highly toxic. And it is difficult to degrade, and the traditional treatment method is difficult to be used for the EDTA-type strong complexed heavy metal wastewater, such as EDTA-Ni to meet the standard treatment. According to the discharge requirements of "Electroplating Pollutant Discharge Standard" (GB21900-2008)_Table 3, the total nickel should be less than 0.1mg / L. Conventional ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C02F101/20C02F11/122
Inventor 王伟廖翔张学良蒋士龙王广灿孙霞
Owner CHINA ELECTRONICS INNOVATION ENVIRONMENTAL TECH CO LTD
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