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Process for removing sexavalent chromium in low concentration waste water containing chromium

A hexavalent chromium, low-concentration technology, applied in chemical instruments and methods, water/sewage treatment, reduced water/sewage treatment, etc., can solve the problems of poor treatment effect, high one-time investment, and large consumption of chemical agents, etc., to achieve The effect of less dosage, improved removal rate and good environmental benefits

Inactive Publication Date: 2006-02-08
NANJING UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0016] The purpose of the present invention is to provide a hexavalent chromium removal rate for the existing low-concentration hexavalent chromium-containing [Cr(VI)] wastewater treatment technology, which has the disadvantages of poor treatment effect, high one-time investment, and consumption of a large amount of chemical agents. It is a method for removing hexavalent chromium in low-concentration chromium-containing wastewater with high efficiency, simple process, no secondary pollution, chromium recovery, waste resource utilization, and good economic and environmental benefits.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0039] Firstly, adjust the concentration of Cr(VI) in low-concentration hexavalent chromium-containing wastewater to 7 mg / L, and then adjust the initial pH value of the wastewater to 2. The waste water is then 60 The Co source (source intensity is 500,000Ci) is irradiated at the irradiation dose of 1kGy. After the wastewater was irradiated, its pH value was adjusted to 7, and it was filtered. The concentration of Cr(VI) in the filtrate was 0.4 mg / L.

Embodiment 2

[0041] Firstly, adjust the concentration of Cr(VI) in the low-concentration hexavalent chromium-containing wastewater to 7 mg / L, then adjust the initial pH value of the wastewater to 2, and then add 0.1% ethanol (volume ratio). The wastewater added with ethanol was passed through 60 The Co source (source intensity is 500,000Ci) is irradiated at the irradiation dose of 1kGy. After the wastewater was irradiated, its pH value was adjusted to 7, and it was filtered. The concentration of Cr(VI) in the filtrate was 0.06 mg / L.

Embodiment 3

[0043] Firstly adjust the concentration of Cr(VI) in the low-concentration hexavalent chromium-containing wastewater to 30 mg / L, then adjust the initial pH value of the wastewater to 5, and then add 0.08% ethanol (volume ratio). The wastewater added with ethanol was passed through 60 The Co source (source intensity is 500,000Ci) is irradiated at an irradiation dose of 5kGy. After the wastewater was irradiated, its pH value was adjusted to 7, and it was filtered, and the concentration of Cr(VI) in the filtrate was 0.3 mg / L.

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PUM

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Abstract

The process of removing sexavalent chromium in low concentration chromium containing waste water features diluting the sexavalent chromium concentration in the waste water to 0.5-50 mg / L concentration; regulating the pH value of the diluted sexavalent chromium waste water to 2-7; irradiating the waste water with gamma-ray for the waste water to absorb irradiation dosage of 1-20 kGy; regulating the irradiated waste water pH value to 6-9; and filtering the waste water. The present invention has low cost, high elimination rate of sexavalent chromium, simple operation and no secondary pollution, and is favorable to environment protect.

Description

technical field [0001] The invention relates to a wastewater treatment method, in particular to a method for treating wastewater containing low-concentration hexavalent chromium (Cr(VI)), specifically a method for removing hexavalent chromium in low-concentration chromium-containing wastewater . Background technique [0002] In nature, chromium mainly exists in two forms: trivalent (Cr(III)) and hexavalent (Cr(VI)). The chemical properties of Cr(III) are stable, and it is easy to form precipitates under neutral and alkaline conditions (Cr(OH) 3 , K sp =6.3×10 -31 ), so the biological toxicity is low. The chemical properties of Cr(VI) are relatively active, and it is easy to penetrate biological cells and cause damage to the body. According to biological data, Cr(VI) has strong carcinogenic and mutagenic effects, and can also induce dermatitis and respiratory system damage. Its toxicity is more than 100 times higher than that of Cr(III). Cr(VI) is one of the 129 hazardo...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C02F1/58C02F1/70
Inventor 袁守军郑正牟艳艳于鑫赵永富盛杰郭照冰江芳帖靖玺周培国唐登勇顾春晖张继彪王仪春
Owner NANJING UNIV