Treatment device for ammonia-containing wastewater and method for treating ammonia-containing wastewater

Abstract

Provided is a treatment device for ammonia-containing wastewater, which can efficiently treat high-concentration ammonia-containing wastewater without using chemical reagents such as scale dispersants and slime control agents. A treatment device for ammonia-containing wastewater, comprising: an ammonia stripping treatment device (12), which performs ammonia stripping treatment on ammonia-containing wastewater above pH 10; a primary reverse osmosis membrane treatment device (14), which treats ammonia-containing wastewater above pH 10. The ammonia stripping treatment water after the ammonia stripping treatment is subjected to the reverse osmosis membrane treatment of the first step, thereby being separated into primary permeated water and primary concentrated water; the secondary reverse osmosis membrane treatment device (16), which is below pH8.5 The second step of reverse osmosis membrane treatment is performed on the primary permeated water, thereby separating into secondary permeated water and secondary concentrated water; and a circulation mechanism, which circulates the secondary concentrated water to the upstream of the ammonia stripping treatment device (12) side.

Description

technical field [0001] The present invention relates to a treatment device and a treatment method of ammonia-containing wastewater containing ammonia, and particularly relates to a treatment device and a treatment method of ammonia-containing wastewater containing ammonia at a high concentration. Background technique [0002] As a treatment method for ammonia-containing wastewater containing ammonia, a method combining ammonia stripping treatment for evaporating ammoniacal nitrogen as ammonia gas and reverse osmosis membrane treatment is known. [0003] For example, Patent Document 1 describes the following treatment method for ammonia-containing wastewater: after adding a scale dispersant to the concentrated water separated by reverse osmosis membrane treatment of ammonia-containing wastewater, ammonia stripping treatment is carried out at a pH of 10 or more, and the extracted Ammonia decomposition, in this method, the reverse osmosis membrane treatment process includes the...

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Problems solved by technology

[0004] However, in the method as in Patent Document 1, there are problems in that the scale dispersant chemical agent is expensive, and it is difficult to optimize the amount of chemical agent added due to water quality fluctuations in ammonia-containing wastewater, etc.

[0009] In order to avoid the further wastewater treatment for removal of ammonia, it may be considered to treat ammonia by recycling the concentrated water treated by the reverse osmosis membrane to the upstream side of the ammonia stripping treatment, but there is a problem that other ion components, organic substances, etc. are also mixed with Ammonia is concentrated and circulated together in the reverse osmosis membrane treatment, and in the distillation tower and reverse osmosis membrane for ammonia stripping treatment, scaling of ionic components, slime pollution caused by organic matter, and reduction in treatment performance occur

[0010] Regarding this problem, there is the following method: adding a scale dispersant or adding a slime control agent to the system similarly to the method of Patent Document 1 to suppress scaling of ionic components and slime pollution caused by organic matter, but there are The following problems: the cost of chemical reagents such as scale dispersants is still spent, and it is difficult to optimize the amount of chemical reagents due to changes in the water quality of ammonia-containing wastewater, etc., and the organic matter contained in scale dispersants and slime control agents Processing becomes necessary again

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