Wastewater softening pretreatment method

Abstract

The invention provides a wastewater softening pretreatment method, comprising: adding an agent into wastewater in a reaction apparatus or reaction tank to carry out chemical reaction; adding magnetized water or dispersant, allowing to react for controlled time of 5-30 min, and controlling reaction PH to 10.5-12; filtering the outflow of reaction with a ceramic membrane, and carrying out PH tempering. The magnetized water or dispersant is added to replace traditional coagulant aids and flocculants to carry out quality modification, so that lattice arrangement and crystal form of flocculent precipitate generated in wastewater can be changed, the flocculent precipitate is downsized and loosened, wastewater softening is achieved by not coagulation precipitation but direct filtering removal, and blocking rarely occurs due to the precipitate attaching to pores of the filter membrane and to the pipe wall of reaction equipment or reaction tank to form scale. Compared with the prior art, the method herein has shorter reaction time, shorter procedure cycle, and smaller equipment area, with membrane pollution avoided and economic cost reduced.

Description

technical field [0001] The invention relates to the field of water treatment, in particular to a wastewater softening pretreatment method. Background technique [0002] In the field of water treatment, the hardness of water generally refers to the total amount of calcium, magnesium and other ions in the form of ions in sewage. Calcium and magnesium ions usually form precipitates with carbonate ions, bicarbonate ions or sulfate ions in water and adhere to the equipment, thus affecting the normal operation of the equipment. Water that contains more soluble calcium and magnesium compounds is also called hard water. The hazards of hard water in industrial production are: first, when used as cooling water, it is easy to cause scale formation on the surface of the heat exchanger, which not only hinders the water flow channel, but in severe cases will reduce the heat exchange efficiency and cause production to stop; second, as the washing of printing and dyeing wastewater Water u...

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to provide a kind of wastewater softening pretreatment method, which solves the long reaction time, many types and large doses of the existing drug-dosing precipitation softening process; the added flocculant and other drugs cause fouling to the membrane system, and the reaction is not good. When it is complete, the sediment will be precipitated in the subsequent process section, blocking pipelines, equipment, etc.; the effluent after dosing and precipitation treatment needs to be tempered, etc.

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