Advanced treatment process for paper-making waste water

Abstract

The invention discloses an advanced treatment process of paper-making wastewater. The process comprises the following steps: introducing the paper-making wastewater after being subjected to secondary biochemical treatment into a micro-aeration iron reduction bed, backfilling iron chips in the micro-aeration iron reduction bed, and carrying out reducing reaction to the paper-making wastewater in the micro-aeration iron reduction bed; introducing effluent water after being processed according to step one into a coagulation basin, and adding a coagulating agent and a coagulant aid to the coagulation basin, so as to promote grains in the water to be agglomerated; introducing effluent water after being processed according to step two to a sedimentation tank for sludge separation; introducing the effluent water in the sedimentation tank into a filter basin for being filtered; introducing the effluent water filtered after being sterilized and disinfected into a reusing water pipe network; introducing sludge in the sedimentation tank and back washing blow-off water in the filter basin into a sewage thicker, and outwardly transporting the sludge and the back washing blow-off water after being dehydrated for disposal; and meanwhile, introducing dehydrate filtrate solution and overflowing liquid in the sewage thicker into the coagulation basin for re-treatment. The process has the advantages of simple process, good decoloration effect and cheap cost.

Description

technical field The invention relates to a method for recycling papermaking wastewater after advanced treatment, in particular to a decolorization process for advanced treatment of papermaking wastewater after secondary biochemical treatment. Background technique Papermaking industrial wastewater is a difficult industrial wastewater with high chroma, high alkalinity, high organic pollutants, and low biodegradability. The wastewater contains a variety of hydrocarbons, phenols, acids, benzene, anthracene, quinones and other organic substances and their derivatives , polymers, halogenated substances, especially lignin are difficult to biodegrade. Papermaking enterprises generally carry out secondary biochemical treatment or even tertiary treatment of their wastewater, but the chemical oxygen demand (COD for short) of the effluent is generally above 150mg / L, and the dilution factor of the chroma is greater than 64 times. Biochemical Oxygen Demand (BOD) 5 ) is usually very low,...

AI Technical Summary

Problems solved by technology

However, there are defects in these conventional processes: the adsorption method needs to add a large amount of adsorbent, which will fail after the adsorption is saturated, the cost is high and a large amount of sludge will be generated; the oxidation method (ozone, hydrogen peroxide, hypochlorous acid, etc.) The decolorization effect is not obvious, and the purpose of decolorization cannot be achieved; the conditions required for high-efficiency decolorization engineering bacteria are harsh, and it is difficult to apply in engineering; the electrolysis method is effective, but the power consumption is high, resulting in unacceptable operating costs; The effect of reducing suspended solids (SS) and desalination is very good, but the removal effect of lignin that causes the color of papermaking wastewater has yet to be verified, and its construction cost and operating cost are very high

Images