Method for reusing municipal wastewater for circulating-cooling water and power-plant boiler feedwater

Abstract

The invention provides a method for reusing municipal wastewater for circulating-cooling water and power-plant boiler feedwater. The method comprises the following steps that: discharged wastewater of a municipal wastewater treatment plant, which is subjected to secondary biochemical treatment and meets discharge standard, enters a moving bed biofilm reactor; BOD and ammonia nitrogen are degraded in the moving bed biofilm reactor; water treated through the moving bed biofilm reactor is led into a rapid mixing tank and is rapidly mixed with coagulant in the rapid mixing tank; the water rapidly mixed with the coagulant enters a flocculation tank; the flocculated water enters an air-floatation filter and is subjected to dissolved air floatation and multi-medium filtration; the water subjected to dissolved air floatation and multi-medium filtration enters an ultrafiltration membrane and is subjected to crude membrane separation; the water subjected to crude membrane separation is led into primary reverse osmosis equipment and subjected to primary membrane separation; the water subjected to primary membrane separation is led into secondary reverse osmosis equipment and subjected to secondary membrane separation; and the water subjected to secondary membrane separation is supplied as boiler feedwater. The method has the advantage of producing water with good quality and high efficiency.

Description

technical field [0001] The invention relates to a method for recycling urban sewage, and further relates to a method for recycling urban sewage to circulating cooling water and power plant boiler feed water. The invention belongs to the technical field of sewage treatment and reuse methods. Background technique [0002] China's water shortage and water pollution are very serious. It is one of the 13 water-poor countries in the world. The per capita water consumption is only a quarter of the world's average level. It ranks 110th among 149 countries in the world and belongs to the serious shortage of water resources. nation. [0003] Industrial enterprises are large water users. In recent years, with the increasing scarcity of water resources, the supply of water sources has become a restrictive factor restricting the expansion and increase of production. On the one hand, there is a serious shortage of water resources. On the other hand, there is a serious problem of industr...

AI Technical Summary

Problems solved by technology

The BOD (biochemical oxygen demand, abbreviated as BOD) of the secondary effluent is lower than 15mg / l. After coagulation and filtration, the BOD is about 5mg / l. The removal ability of organic matter and ammonia nitrogen is not strong, and the effluent quality is unstable. , affect the subsequent UF and RO treatment, reduce the life of UF membrane and RO membrane, and cause discontinuous water supply

[0006] At the same time, this process has the defects of long treatment process, large infrastructure investment, high drug consumption, and high operating costs.

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