Sewage decoloration method

Abstract

The invention provides a sewage decoloration method. A chemical oxidation method is adopted in the sewage decoloration method. The sewage decoloration method is characterized in that sewage which is treated with biotechnology is conveyed into a first decoloration tank through a pump, and meanwhile moderate decoloration agents A are added into the first decoloration tank. The sewage in the first decoloration tank is conveyed into a second decoloration tank through a pump, and meanwhile moderate decoloration agents B are added into the second decoloraton tank. The sewage in the second decoloration tank is conveyed into a waste water clarification tank through a pump, meanwhile, flocculants are added into the clarification tank for standing for 1-2h, and clear water is discharged, wherein the chromaticity of the clear water is smaller than 50. The decoloration agents A comprise, by weight, 30-60% of calcium hypochlorite, 30-40% of sodium hypochlorite and 0-40% of 10% hypochlorous acid solution. The moderate decoloration agents B comprise, by weight, 10-20% of acetic acid, 75-89% of 30% hydrogen peroxide solution and 1-5% of ozone. The sewage decoloration method has the advantages of being simple in technology, good in discharged water quality, low in chromaticity and the like.

Description

technical field [0001] The invention relates to a sewage decolorization method, which belongs to the technical field of sewage treatment. Background technique [0002] GB8978-1996 "Comprehensive Wastewater Discharge Standard" has the discharge requirements for chroma (dilution multiple method): first-level discharge standard: 50 for dye industry; 50 for other discharge units; 100 for mining, mineral processing, and coal processing industries; Secondary emission standards: 180 for dye industry; 80 for other emission units; 300 for mining, ore dressing, and coal preparation industries; 500 for gold ore dressing. GB18919-2002 "Pollutant Discharge Standards for Urban Sewage Treatment Plants" stipulates that the chromaticity (dilution multiple method) discharge standard is 30 for the first grade; 40 for the second grade; and 50 for the third grade. It can be seen from the above two national standards that the sewage discharge standard is very strict on the chromaticity index. T...

AI Technical Summary

Problems solved by technology

However, the main components of the decolorizing agent used in the chemical oxidation method are calcium hypochlorite, sodium hypochlorite, hypochlorous acid, etc. Therefore, although the chromaticity of the decolorized sewage is low, the water quality contains a small amount of active chlorine, which is harmful to biological cells. Strong toxicity, capable of harming aquatic plants and animals, and threatening human health

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