A treatment method and device for high-salinity, high-ammonia-nitrogen rare earth production wastewater

Abstract

The invention discloses a treatment process method and device for high-salinity and high-ammonia-nitrogen rare-earth production wastewater, and particularly relates to a wastewater treatment process with efficient desalination and denitrification effects and combining an electrodialysis process, a three-effect condensation crystallization process and an integral anaerobic ammonia oxidation process. Rare-earth production wastewater, after passing through pretreatment units such as a grille, an adjusting pool, a multi-media filter and the like, enters an electrodialysis device, and after being subjected to electrodialysis treatment, the wastewater is divided into concentrated liquid and desalinated liquid; the concentrated liquid enters a three-effect condensation crystallizer to carry out solid-liquid separation; and the desalinated liquid and water discharged from the three-effect condensation crystallizer enter an integral anaerobic ammonia oxidation reactor to carry out biological denitrification reaction. The method and device disclosed by the invention are perfect in process, simple in operation, flexible in control, low in running cost, good in sewage treatment effect, and high in efficiency.

Description

technical field [0001] The invention relates to a processing method and device for high-salinity, high-ammonia-nitrogen rare earth production wastewater, and belongs to the technical field of sewage treatment. Background technique [0002] my country is a big country in rare earth mining and processing. After half a century of development, my country's rare earth industry has made great achievements. environmental problems. From October 1, 2011, the Ministry of Environmental Protection of my country began to implement the "Discharge Standard of Rare Earth Industrial Pollutants (GB 26451-2011)", which has stricter requirements on the quality of wastewater discharged from the rare earth industry. Rare earth wastewater contains extremely high concentrations of ammonia nitrogen, as well as high salinity and concentration of heavy metal elements. It is difficult for the current treatment processes of various enterprises to meet the latest industrial wastewater discharge requireme...

AI Technical Summary

Problems solved by technology

Some R&D personnel mixed ammonia nitrogen wastewater produced in rare earth separation enterprises with magnesium-containing wastewater, and then added Na 3 PO 4 12H 2 O is used as a precipitating agent to adjust the pH of the solution to 9.0, which can make the removal rate of ammonia nitrogen reach 98.6%. This not only solves the salinity problem caused by magnesium-containing wastewater, but also solves the problem of ammonia nitrogen pollution. However, the precipitant used in the magnesium ammonium phosphate method The cost of phosphate is relatively high, and it has not been applied in industry at present

[0014] To sum up, the cost of ammonia distillation and concentration method is high, low concentration wastewater needs to be concentrated first, and product sales are difficult; the break point chlorination method is effective in treating low concentration ammonia nitrogen wastewater, but secondary pollution should be prevented; the efficiency of ammonia stripping method is not high, and the recovery of ammonia is difficult, so these methods are still in the research stage

The MAP method has large processing capacity, low operating cost, and the sediment can be recycled as fertilizer, which has great practical prospects. However, due to the high cost of phosphate, it is still difficult for enterprises to accept it.

Although ammonia nitrogen can be treated by different methods, it is difficult to meet the emission standards by one method, and it will cause a lot of manpower, material resources and energy consumption, and the treatment cost is high

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