Method for improving alkalinity removal effect of single-stage reverse osmosis desalination process

Abstract

The invention relates to a method for improving the alkalinity removal effect of a single-stage reverse osmosis desalination process, which is applied to a desalted water system of a medium-low pressure boiler, in particular to a desalted water system taking a water body with higher alkalinity and high hardness in northwest China as raw water. The acid adding device is additionally arranged at thefront end of the reverse osmosis device, the pH of raw water is adjusted to 7-7.5, the alkalinity in the water is removed, and the alkalinity removal effect is integrally improved through the interception effect of the reverse osmosis device; and a carbon remover is additionally arranged at the rear end of the acid adding device to remove generated free CO2 and remove CO2 dissolved in raw water which cannot be removed by the reverse osmosis device. The alkalinity removal effect of the single-stage reverse osmosis desalination process is improved, and the problems that boiler steam is slightlyacidic and the like due to the fact that the alkalinity removal effect is not ideal are solved; the problem of scaling of insoluble salts such as CaCO3 and slightly soluble salts such as MgCO3 on thesurface of the membrane is solved, and the service life of the reverse osmosis device is prolonged; CO2 dissolved in raw water which cannot be removed by the reverse osmosis device is removed, and the effluent quality is improved.

Description

technical field [0001] The invention relates to a method for improving the alkalinity removal effect of a single-stage reverse osmosis desalination process, which is applied to the desalinated water system of medium and low pressure boilers, especially the water body in Northwest China with relatively high alkalinity and high hardness as raw water desalination system. Background technique [0002] Medium and low-pressure boilers are often used in industries that use saturated steam as a heat medium. In the article "Concept and Practice of Chemical Fiber Boiler Water Treatment", a reverse osmosis desalination water production process is disclosed, which consists of a multi-media filter→activated carbon filter →Security filter→High pressure pump→Reverse osmosis device→Desalinated water pool, the disadvantage is that the removal effect of alkalinity is not ideal when dealing with high alkalinity water, and free CO in water cannot be removed 2 , it is easy to cause CaCO on the ...

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Problems solved by technology

[0003] The invention overcomes the disadvantages of the unsatisfactory alkalinity removal effect and the fouling of the slightly soluble salt on the membrane surface in the prior art, and provides a method for improving the alkalinity removal effect of the single-stage reverse osmosis desalination process, which solves the problems caused by Single-stage reverse osmosis has unsatisfactory effect on alkalinity removal, resulting in the problem of partial acidity of steam and the problem of fouling on the membrane surface