Method and device for treating and purifying sewage in a membrane coupling way

Abstract

The invention provides a device and a method for treating and purifying high-concentration industrial sewage in a membrane coupling way. Raw water primarily enters a membrane evaporation tank for primary circulation evaporation, alkali is added into overflowed concentrated water, primary reaction filtration is performed in an immersing ultrafiltration reactor, filtered water enters a secondary membrane evaporation tank for secondary circulation evaporation after being pumped by a pump, and overflowed concentrated water enters a secondary immersing ultrafiltration reactor for reaction filtration after alkali and flocculating agent are added. A membrane evaporation assembly adopts a hollow fiber membrane assembly with a casing, and is vertically immersed into or half immersed into an evaporation tank, hot water enters from a lower opening of the hollow fiber membrane assembly through the pumping of the circulation pump and is upwards pumped out through a tube pass, and the hot water is circulated and evaporated through a reducing membrane. The membrane evaporation tanks are internally provided with baffle plates, and supernatant liquid after being settled primarily enters membrane regions through the baffle plate, thereby the membrane pollution is reduced. The invention greatly reduces the sewage emission, lowers the operation cost of a membrane evaporation and concentration system, realizes the purification and the recycling of the industrial sewage and achieves the purposes of saving water and reducing the emission. The invention can concentrate the reverse osmosis by about 100 times usually and can greatly reduce the sewage emission. Concentrated liquid and sludge can be directly dried by a general evaporator so as to achieve zero emission.

Description

technical field [0001] The invention relates to a water treatment system and a treatment method, in particular to a membrane coupling purification treatment method for industrial sewage purification treatment. Background technique [0002] Circulating cooling water is a major part of industrial water consumption. In petrochemical, electric power, steel, metallurgy and other industries, the consumption of circulating cooling water accounts for 50-90% of the total water consumption of enterprises. The cooling water of some power plants and chemical enterprises accounts for 90-95% of total water consumption. During the continuous circulation of circulating cooling water in the system, due to the change of water temperature and flow rate, the water evaporates continuously, the inorganic ions and organic matter gradually concentrate, and the Ca in the water 2+ , Mg 2+ , Cl - Plasma, dissolved solids, and suspended solids increase accordingly, coupled with pollutants in the air...

AI Technical Summary

Problems solved by technology

Usually, after conventional biochemical treatment, ultrafiltration or microfiltration plus reverse osmosis is used to purify and reuse most of the sewage. However, there are still two problems with the use of reverse osmosis technology: one is that reverse osmosis technology has no effect on the treated wastewater. Water treatment requires high pretreatment, and usually requires the use of ultra- and microfiltration technology as pre-treatment, and the raw water temperature is usually not higher than 40 ° C, resulting in high equipment investment and high operating costs. Second, the water recovery rate is low, generally only It can reach about 70%, and there is still about 30% concentrated water discharge, which is a large amount of discharge

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