Method for removing ammonia and nitrogen in garbage percolate

Abstract

The invention discloses a method of removing ammonia nitrogen in landfill leachate, pertaining to the wastewater treatment field. The method mainly comprises the steps that magnesium salts and phosphates are first added into the landfill leachate, regulating the pH value and the mole ratio of the magnesium salts and the phosphates and the ammonia nitrogen, which are mixed and stirred so as to produce deposit of magnesium ammonium phosphate; supernatant and the deposit are next separated and precipitation and dehydration are then carried out; blast furnace slag is then added into the dehydrated magnesium ammonium phosphate, the weight ratio of the magnesium ammonium phosphate and the blast furnace slag is controlled, mixed by adding water, and then the magnesium ammonium phosphate is treated with pyrolysis with pyrolysis time and temperature being controlled; ammonia gas generated by the pyrolysis is treated by bio-trickling filter bed and a solid product by the pyrolysis is recovered and recycled in the treatment of the ammonia nitrogen. The invention can not only remove the ammonia nitrogen by recycling chemical precipitation agent with charges saved, but also realize reclamation utilization of the blast furnace slag. The concentration of effluent of the ammonia nitrogen can decrease below 100mg / l after being treated by the invention, which greatly improves conditions for consequent biochemical treatment.

Description

technical field

[0001] The invention relates to a method for treating landfill leachate, in particular to a method for removing ammonia nitrogen in landfill leachate. Background technique

[0002] The composition of landfill leachate is quite complex. It not only contains high concentrations of organic matter, but also contains high concentrations of ammonia nitrogen, alkali and heavy metals. It is a kind of difficult-to-treat wastewater. In the initial stage of landfill, the biodegradability of landfill leachate is good, and the B / C reaches about 0.7. However, with the extension of landfill time, the mass concentration of ammonia nitrogen increased, and the mass ratio of C to N was less than 3. At the same time, the biodegradability of landfill leachate decreased, and B / C was lower. At present, the most economical and effective way to remove high-concentration COD in landfill leachate is anaerobic biological treatment. However, because high concentrations of ammonia nitro...