A reverse osmosis pretreatment method when reclaimed water is reused in power plants

Abstract

The invention discloses a reverse osmosis pre-treatment method for recycling reclaimed water in an electric power plant. The reverse osmosis pre-treatment method comprises the following steps: 1) coagulating and clarifying the reclaimed water; 2) filtering in a filtering tank with variable pore aperture; 3) filtering with a multi-medium filter; 4) softening with a strong-cationic sodium ion exchanger; 5) softening with a double-chamber weak-acid and strong-acid cationic exchanger; and 6) adjusting the pH value. The reverse osmosis pre-treatment method has the advantages that: the reclaimed water is pre-treated before reverse osmosis, thereby greatly reducing the reverse osmosis scale formation and contamination blockage risks caused by hardness, COD (chemical oxygen demand), SiO2 and the like in the reclaimed water, prolonging the service life of a reverse osmosis membrane element, and improving the reverse osmosis operation stability of the electric power plant.

Description

technical field [0001] The invention relates to a pretreatment method of recycled reclaimed water before reverse osmosis applied in power plants, in particular to a reverse osmosis pretreatment method when reclaimed water is reused in power plants. Background technique [0002] Reuse of reclaimed water is an effective way to solve the shortage of water resources in power plants, and it is also an important condition for new expansion of power plants. The composition of urban water quality is complex, the salinity, COD, SiO 2 , ammonia nitrogen, turbidity and chromaticity and other indicators are doubled compared with natural water bodies, and contain a large amount of surfactant discharged from production and life, when it is reused for reverse osmosis treatment, it is very easy to cause reverse osmosis Fouling leads to a decline in reverse osmosis output, shortened operating cycle, frequent chemical cleaning, and insufficient water supply to the power plant. In severe case...

AI Technical Summary

Problems solved by technology

The composition of urban water quality is complex, the salinity, COD, SiO 2 , ammonia nitrogen, turbidity and chromaticity and other indicators are doubled compared with natural water bodies, and contain a large amount of surfactant discharged from production and life, when it is reused for reverse osmosis treatment, it is very easy to cause reverse osmosis Fouling, resulting in a decline in reverse osmosis output, shortened operating cycle, frequent chemical cleaning, insufficient water supply to the power plant, and severe cases will shorten the life of the reverse osmosis membrane element, which greatly affects the stability of the reverse osmosis operation of the power plant

[0003] At present, most of the power plants using reclaimed water reuse ultrafiltration as the reverse osmosis pretreatment process. Ultrafiltration occupies a large area and has high investment costs. The SDI value is reduced to the required range, but the removal effect of ultrafiltration on organic matter and microorganisms in water is poor. During operation, ultrafiltration and reverse osmosis are often fouled successively, and reverse osmosis has a decrease in water production, an increase in pressure difference, and a desalination rate. Decline, etc., the operation stability is affected

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