Zero-discharge system for producing ammonium salt from ammonia-nitrogen-containing wastewater and treatment process thereof

Abstract

The invention belongs to the technical field of sewage treatment, and discloses a zero-discharge system for producing an ammonium salt from ammonia-nitrogen-containing wastewater. The system comprisesa PH regulating region I, a precipitation separation region, a sand filtration region, an ammonia-nitrogen removal membrane region, a PH regulating region II and an evaporative crystallization regionwhich are sequentially communicated through pipelines. The method comprises the following steps: adding an alkali into ammonia-nitrogen-containing wastewater to adjust the pH value to 10-13, so thatammonia nitrogen in the wastewater is converted into free ammonia NH3; carrying out precipitation separation on large particles and insoluble suspended matters generated by an alkalifying reaction; making the supernatant enter an ammonia-nitrogen removal membrane group, wherein free ammonia diffuses through the membrane holes to form an ammonium salt solution with an out-of-membrane absorption liquid; adjusting the pH value of the absorption liquid to be neutral; and separating distilled water and the ammonium salt through evaporative crystallization, wherein the ammonium salt can be recycledat the product level, and the deamination wastewater can be discharged after reaching the standard. According to the invention, the investment and operation cost is low, operation is stable, energy consumption is low, the secondary pollution problem cannot be generated, resource utilization of the ammonia-nitrogen-containing wastewater and zero discharge of the ammonia-nitrogen-containing wastewater are achieved, and the method is worthy of popularization.

Description

technical field [0001] The invention relates to the technical field of sewage treatment, and more specifically relates to a zero discharge system for producing ammonium salts from wastewater containing ammonia nitrogen and a treatment process thereof. Background technique [0002] With the rapid development of industry and agriculture, it brings about the gradual increase of ammonia nitrogen pollution sources, such as chemical fertilizers, coking, petrochemical, pharmaceutical, food, landfill and other industries. Ammonia nitrogen is the main cause of environmental pollution. Ammonia nitrogen is the main object of polluting water bodies. It consumes a large amount of oxygen while oxidizing and decomposing, which leads to a decrease in dissolved oxygen content in water, threatens the normal growth of aquatic animals, and even causes death. Ammonia nitrogen is also oxidized to nitrite nitrogen under the action of microorganisms, and then combines with protein to form nitrosami...

AI Technical Summary

Problems solved by technology

[0003] Various ammonia nitrogen removal technologies currently used include chemical methods, biological methods, physical methods, combined physicochemical and biological methods to treat ammonia nitrogen in wastewater, and most of these methods have problems such as investment, operating costs, and secondary pollution.

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