Method for processing high-concentration ammonia nitrogen in rare earth wastewater

Abstract

The invention discloses a method for processing high-concentration ammonia nitrogen in rare earth wastewater. The method comprises the specific steps as follows: firstly, taking 100-mesh to 150-mesh granular active carbon for preparing an electrode with catalytic activity; secondly, filling the rare earth wastewater with the high-concentration ammonia nitrogen into an electrolytic tank; thirdly, adding a NaCl solid and electrolyzing for 3-4h at the voltage of 36-110V; and finally, reducing the concentration of the ammonia nitrogen in the discharged rare earth wastewater to be less than 0.2mg / L. According to the method, the concentration polarization of ion concentration in a surrounding solution is eliminated by the granular active carbon and the electrode with catalytic activity, so thatthe redox reaction is conducted to convert the high-concentration ammonia nitrogen in the rare earth wastewater into nitrogen, and the nitrogen is discharged into the air; the ammonia nitrogen removal rate is more than 99.8%; the voltage is low; the energy consumption is low; and the secondary pollution risk is avoided.

Description

technical field [0001] The invention relates to a method for treating high-concentration ammonia nitrogen in rare earth wastewater, belonging to the field of sewage treatment. Background technique [0002] There are three types of wastewater discharged by pharmaceuticals during the production and smelting of rare earths, mainly acidic wastewater generated by spraying and purifying tail gas of rare earth concentrate roasting, ammonium salt wastewater generated by rare earth carbonate production process, and ammonium salt wastewater generated by rare earth separation. Among them, the rare earth industry produces more than 20 million tons of wastewater every year, with an ammonia nitrogen content of 300-5,000 mg / L, exceeding the national discharge standard by ten to hundreds of times. Ammonia nitrogen pollutants in wastewater is one of the three major wastewater produced in rare earth smelting. Ammonia nitrogen in water quality indicators is an important pollutant that causes w...

AI Technical Summary

Problems solved by technology

[0004] In order to seek a method for electrolytic removal of high-concentration ammonia-nitrogen in rare-earth wastewater that can simultaneously achieve low power consumption, low cost, and avoid the risk of secondary pollution, the present invention provides a method for treating high-concentration ammonia-nitrogen in rare-earth wastewater. The catalytically active electrode eliminates the concentration polarization of the ion concentration in the surrounding solution, thereby generating a redox reaction to convert the high concentration of ammonia nitrogen in the dilute wastewater into nitrogen and discharge it into the air. The removal rate of ammonia nitrogen is as high as 99.8%, which solves the problem in the prior art The problems of high voltage and high energy consumption avoid the risk of secondary pollution