Polluting and plugging cause analysis and determination method for reverse osmosis system in reuse process of circulating water effluent of power plant and chemical cleaning method

Abstract

The invention discloses a polluting and plugging cause analysis and determination method for a reverse osmosis system in reuse process of circulating water effluent of a power plant and a chemical cleaning method. A polluting and plugging material is determined by experiments, a cleaning method is analyzed and determined according to the polluting and plugging material, analysis shows that the main ingredient of the polluting and plugging material is calcium sulfate scale, which determines the complexity of chemical cleaning, and polluting and plugging of calcium sulfate scale is difficult to remove by reverse osmosis equipment during actual operation. Therefore, the reverse osmosis chemical cleaning method is adopted and comprises the following steps: flushing of the reverse osmosis system, pickling with hydrochloric acid, cleaning with sodium carbonate + EDTA and cleaning with hydrochloric acid. An existing reverse osmosis on-line cleaning system can be utilized to realize on-line reverse osmosis cleaning of calcium sulfate scale, the operation is simple, a short time is spent, the influence on power supply of the power plant is less, cleaning chemicals are simple and easily accessible, and the cleaning cost is low.

Description

technical field [0001] The invention relates to a method for analyzing and cleaning the cause of fouling in a reverse osmosis system. Background technique [0002] Sewage reuse of circulating water is an effective way to solve the shortage of water resources in power plants and realize the reduction of sewage discharge and the utilization of sewage resources. Circulating water and sewage water quality components are complex, the salt content in water, SO 4 2- , Ca 2+ , Alkalinity and other indicators are doubled compared with natural water bodies. When it is reused for reverse osmosis treatment, it is very easy to cause reverse osmosis scaling, resulting in a decrease in reverse osmosis output, shortened operation cycle, frequent chemical cleaning, and power plants. Insufficient water supply will shorten the life of reverse osmosis membrane elements in severe cases, which greatly affects the stability of reverse osmosis operation in power plants. [0003] At present, in ...

AI Technical Summary

Problems solved by technology

Circulating water and sewage water quality components are complex, the salt content in water, SO 4 2- , Ca 2+ , Alkalinity and other indicators are doubled compared with natural water bodies. When it is reused for reverse osmosis treatment, it is very easy to cause reverse osmosis scaling, resulting in a decrease in reverse osmosis output, shortened operation cycle, frequent chemical cleaning, and power plants. Insufficient water supply will shorten the life of reverse osmosis membrane elements in severe cases, which greatly affects the stability of reverse osmosis operation in power plants

[0003] At present, in the operation of power plants that use circulating water and wastewater reuse, calcium sulfate scales often appear in the second stage of reverse osmosis. The water production rate of reverse osmosis decreases, the pressure difference increases, and the desalination rate decreases, which affects the operation stability.

At present, most reverse osmosis membrane elements can only be taken out after calcium sulfate fouling, and long-term off-line cleaning is performed, which not only affects the normal operation of reverse osmosis, but also affects the normal water supply of the unit, and the cleaning cost is high, which affects the economy of the power plant benefits, reducing the enthusiasm of power plants to reuse circulating water and sewage