WEIChuan-xu,SUNKe-chun,CHENGXue-jian,et al.Nitrogen Recovery in Rural Waste Transfer Station Leachate by Magnesium Ammonium Phosphate Crystallization Process[J].China Water & Wastewater,2023,39(23):8-14.
Nitrogen Recovery in Rural Waste Transfer Station Leachate by Magnesium Ammonium Phosphate Crystallization Process
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第39卷
Number:
第23期
Page:
8-14
Column:
Date of publication:
2023-12-01
- Abstract:
- The nitrogen in rural waste transfer station leachate was treated and recovered by the crystallization method of magnesium ammonium phosphate. The effects of pH, magnesium-nitrogen molar ratio, and stirring intensity on the recovery rate of nitrogen were investigated through small-scale experiments. And the effects of ammonia nitrogen load and operation mode on the recovery rate of ammonia nitrogen were explored through the pilot experiment. The characterization, toxicity analysis and economic analysis of the precipitated product were carried out. The experimental results showed that the max recovery rate of nitrogen was 72.8% under the optimum conditions with pH of 10.0, molar ratio of magnesium to nitrogen of 1.2 and GT value of 20×104. The pilot test results showed that high ammonia nitrogen loading was conducive to improving the recovery rate of ammonia nitrogen, and the maximum recovery rate was 74.8% at ammonia nitrogen loading of 600 mg/L. In both continuous and sequencing batch modes, the best recovery rate of nitrogen in the pilot-scale reaction could be stably higher than 60%. Toxicity analysis showed that the effluent from the supernatant had low biological toxicity, and the precipitated products (mainly MAP) were basically non-toxic to some plant seeds like cucumber seeds. Economic analysis showed that it was feasible to prepare agricultural slow-release fertilizer by synthesizing MAP through crystallization reaction.
Last Update:
2023-12-01