Auto-precipitation pretreatment method of high-salt wastewater

Abstract

An auto-precipitation pretreatment method of high-salt wastewater comprises steps as follows: 1) a proper amount of dispersant is added to the high-salt wastewater, and then the wastewater enters a primary membrane separation system for treatment via a high-pressure pump; 2) concentrated water of the membrane separation system is collected, and a small amount of magnesium removing agent and a compound flocculant are added, so that the concentrated water is destabilized to produce precipitates; 3) the concentrated water of the membrane separation system is subjected to solid-liquid separation with an efficient precipitation technology, high-salt water returned by a supernatant and incoming water reenters the membrane separation system for treatment to form circulation, precipitates are products mainly comprising CaSO4 and Mg(OH)2 and are recycled to be used as desulfurizers; 4) the salt of water produced by the membrane separation system contains monovalent ions, the salt content is decreased, the water is classified, evaporated and treated after being subjected to membrane concentration and recycled to be used as fresh water, and salts mainly containing monovalent NaCl and KCl are recycled.

Description

technical field [0001] The invention relates to a method for treating industrial sewage and wastewater, in particular to a method for treating high-salt water, and belongs to the technical industry of industrial sewage and wastewater treatment. Background technique [0002] High-salt wastewater generally refers to wastewater with a total salt content ≥ 1%, which is one of the refractory wastewater. The discharge of high-salt wastewater will bring serious pollution to the environment, especially industrial saline wastewater, which contains high concentrations of inorganic salts and a large amount of refractory organic or toxic substances, and the discharge has a tendency to increase sharply; such If the wastewater is directly discharged into the natural water body without treatment, it will inevitably cause great harm to the animals and plants in the water body, as well as domestic drinking water and industrial and agricultural production water, and will cause huge pressure o...

AI Technical Summary

Problems solved by technology

When the hardness is high, it is necessary to add a large amount of lime and sodium carbonate to reduce the hardness, and a coagulation sedimentation tank and a large amount of chemicals are required, which makes the cost of infrastructure and chemicals often relatively high; at the same time, the normal coagulation and sedimentation equipment The operation needs to adjust a large number of operating parameters, and the dosage of different chemicals varies greatly with the salinity of the wastewater, and the actual operation is more cumbersome or causes unnecessary waste of chemicals; moreover, the effluent effect of the coagulation sedimentation tank will be affected. Due to the influence of different operating parameters and conditions, the water outlet stability is not high

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