Calcium removal system and method for ion exchange regenerated sewage

Abstract

The invention discloses a calcium removal system for ion exchange regenerated sewage. The calcium removal system comprises a waste acid buffer pool, a leaching sewage buffer pool, a waste alkali buffer pool, a sodium hydroxide storage tank, a calcium removal agent sodium carbonate storage tank, an adjusting pool, a mixer, a settling pool, a vacuum drum filter, a carbon dioxide storage tank and an adjusting tank. The invention also discloses a calcium removal method for ion exchange regenerated sewage. Ion exchange regeneration sewage is divided into calcium-containing waste acid, waste alkali and leaching sewage, so that the calcium removal load can be reduced by about 85%; the waste alkali is used for neutralizing the calcium-containing waste acid, so that the alkali consumption for adjusting the pH before the calcium remover is added can be greatly reduced; the waste alkali is separated from ion exchange leaching sewage, so that the waste alkali is utilized, and the consumption of carbon dioxide for neutralizing pH before the leaching sewage enters an anaerobic tower is reduced; and precipitated calcium is separated from sewage through vacuum drum filtration, and the separation effect is improved. The method is high in calcium removal efficiency, the concentration of calcium ions in the calcium-removed sewage is controlled within 20 ppm, and the risk of scaling and sludge caking of a sewage system pipeline is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of treatment of decommissioned recycled sewage, in particular to a decalcification system and method for decomposed and regenerated sewage. Background technique [0002] In the sugar industry, it is often necessary to add a large amount of slaked lime for flocculation and precipitation in the pretreatment stage of the sugar liquid. Although the carbon dioxide is settled, the calcium ions in the material before separation are still high (1000ppm~2000ppm). During the process, it is adsorbed by the separation resin, and enters the sewage through the separation and regeneration process, resulting in the concentration of calcium ions in the separation and regeneration sewage often reaching 1000ppm or more. If calcium removal treatment is not performed, the sewage treatment system is prone to fouling, and often needs to be stopped for cleaning. Affect the normal operation of production. [0003] The presence of a...

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Problems solved by technology

[0002] In the sugar industry, it is often necessary to add a large amount of slaked lime for flocculation and precipitation in the pretreatment stage of the sugar liquid. Although the carbon dioxide is settled, the calcium ions in the material before separation are still high (1000ppm~2000ppm). During the process, it is adsorbed by the separation resin, and enters the sewage through the separation and regeneration process, resulting in the concentration of calcium ions in the separation and regeneration sewage often reaching 1000ppm or more. If calcium removal treatment is not performed, the sewage treatment system is prone to fouling, and often needs to be stopped for cleaning. Affect the normal operation of production

[0003] The existence of a large amount of calcium ions in sewage not only easily causes fouling of sewage pipes, but also the existence of sludge will also affect the operation of water systems. At present, there have been many researches on calcium removal

For example, the patent No. CN201410414823.9 discloses a sewage decalcification device for the paper industry. By improving the decalcification device, the continuous treatment of sewage is realized and the decalcification efficiency of the water system is improved. However, the patent uses filter sand The cost of calcium removal is high, and the efficiency of calcium removal is low. It is only suitable for the removal of calcium before sewage is discharged, which has great limitations.

Another example is that the patent No. CN201610666207.1 discloses a sewage treatment process and its equipment. Calcification is carried out by adding a decalcifier, but a large amount of quicklime is added in the pH adjustment stage, which increases the difficulty of solid-liquid separation in the later stage. At the same time, quicklime The alkalinity is relatively weak, and the treatment cost for adjusting pH is relatively high. In addition, adding quicklime to the sewage will generate a lot of heat, and the sewage is prone to produce many bad smells, so it is not suitable for the sewage treatment of the sugar industry

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