Zero emission technology for wastewater

Abstract

The invention discloses a zero emission technology for wastewater. The technology comprises steps as follows: (1), pretreatment: the wastewater passes through a segmented filter, and particulate matter with grain size larger than 100 mu m is removed; (2), FO (forward osmosis): the pretreated wastewater passes through an FO membrane; (3), concentrated wastewater obtained after the pretreated wastewater passes through the FO membrane is subjected to low-temperature evaporative crystallization by a low-temperature evaporative crystallizer; an FO light draw solution obtained after the wastewater passes through the FO membrane is pumped into a high-salt concentration membrane by a high-pressure pump; produced concentrated water is taken as a draw solution to be recovered, and produced fresh water is taken as industrial water. The technical scheme has beneficial effects as follows: 1, pretreatment is simple; 2, the draw solution is recovered with the high-salt concentration membrane technology, the recovery is simple, and no chemical is required to be added; 3, the low-temperature evaporative crystallizer is driven by air in the evaporation process, and required temperature is about 30 DEG C and is the lowest temperature for evaporation in current water treatment industry.

Description

Technical field [0001] The invention relates to a waste water treatment method, in particular to a waste water zero discharge process, belonging to the technical field of environmental protection. Background technique [0002] Since the "Ninth Five-Year Plan", my country has concentrated its efforts on comprehensive improvement of the "Three Rivers and Three Lakes" and other key river basins. Since the "Eleventh Five-Year Plan", we have vigorously promoted pollution reduction and water environmental protection has achieved positive results. However, the serious situation of water pollution in my country has not been fundamentally contained. Regional, compound, and compressed water pollution has become increasingly prominent and has become the most prominent factor affecting my country's water security. The prevention and control situation is very severe. To this end, twelve departments including the Ministry of Environmental Protection and the Development and Reform Commission jo...

AI Technical Summary

Problems solved by technology

Some traditional technologies are used in the treatment of these wastewaters. The system equipment requires complex pretreatment and is prone to fouling, which makes the equipment unable to operate stably. The equipment used must be resistant to high salt corrosion and has high requirements for materials.

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