Device and method for recycling low concentration ammonia nitrogen wastewater

Abstract

The invention discloses a device for recycling low concentration ammonia nitrogen wastewater, which comprises a storage tank for the low concentration ammonia nitrogen wastewater before filtration, asurface filter, a storage tank for the low concentration ammonia nitrogen wastewater after filtration and an ultrafiltration and nanofiltration system, wherein the storage tank for low concentration ammonia nitrogen wastewater before filtration, the surface filter, the storage tank for lowconcentration ammonia nitrogen wastewater after filtration and the ultrafiltration and nanofiltration system are sequentially connected through pipelines. The invention also discloses a method for recycling the low concentration ammonia nitrogen wastewater. According to the device and the method for recyclinglow concentration ammonia nitrogen wastewater, the low concentration ammonia nitrogen wastewater treatment process is shortened, the product quality remains unaffected, and the mixing and recycling of the low concentration ammonia nitrogen wastewater generated by different kinds of rare earth carbonate products are achieved.

Description

technical field [0001] The invention relates to a wastewater treatment technology, in particular to a device and method for recycling low-concentration ammonia nitrogen wastewater. Background technique [0002] The rare earth elements contained in northern rare earth mines are mainly La, Ce, Pr, and Nd. Most of the single or mixed rare earths produced in the production process are transferred to the next process in the form of carbonate. In the production process of rare earth carbonate, the leaching wastewater produced by washing rare earth carbonate contains low concentration of ammonia nitrogen, a small amount of rare earth carbonate particles and trace amounts of rare earth ions. If it is discharged directly, it will cause ecological damage. [0003] At present, the main treatment methods for this low-concentration ammonia nitrogen wastewater are: [0004] 1. Concentrated crystallization method [0005] After the low-concentration ammonia nitrogen wastewater is filtere...

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Problems solved by technology

[0009] The wastewater treated in this way still contains a certain concentration of rare earth ions. In order to avoid the pollution of different rare earth ions to high-purity rare earth products, it can only be reused in the corresponding production lines.

The amount of leaching wastewater produced by different types of rare earth carbonates is unbalanced. When reused in the respective precipitant preparation processes, there will be some surpluses and some shortages

Because the precipitant cannot be uniformly prepared, all the wastewater cannot be reused in the production line, resulting in a waste of part of the water, and the equipment used is large, occupying a large area, and the utilization rate is low; the filter press used for filtering wastewater cannot be sealed and needs to be manually disassembled regularly Filter plate, poor operating environment, high labor intensity

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