Alternative route for the recovery of nitrogen as ammonium phosphate crystals from high strength waste streams
Autor: | Oh Kyung Choi, Dandan Dong, Jae Woo Lee, Kwanhyoung Lee, Yongsuk Hong |
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Rok vydání: | 2017 |
Předmět: |
Stripping (chemistry)
Ammonium phosphate Inorganic chemistry chemistry.chemical_element 02 engineering and technology 010501 environmental sciences 021001 nanoscience & nanotechnology Phosphate 01 natural sciences Nitrogen law.invention chemistry.chemical_compound Ammonia chemistry Volume (thermodynamics) Mechanics of Materials law Crystallization 0210 nano-technology Waste Management and Disposal Phosphoric acid 0105 earth and related environmental sciences |
Zdroj: | Journal of Material Cycles and Waste Management. 20:578-584 |
ISSN: | 1611-8227 1438-4957 |
Popis: | This study suggests a method for the recovery of nitrogen in waste or wastewater as ammonium phosphate crystals. Recovered crystals were a mixture of mono-ammonium phosphate (MAP) and di-ammonium phosphate (DAP), which are valuable fertilizers. A lab-scale system was constructed with an ammonia stripper and absorber with phosphoric acid solution. Formation of ammonium phosphate crystals was dependent on the concentration and volume of phosphoric acid in the absorber. The absorption efficiency of ammonia in the absorber increased as the concentration and volume of phosphoric acid increased. However, the crystals formed better in a smaller volume of absorbing solution. When the N/P ratio in the ammonia absorbed solution reached 0.38 in a continuous stripping condition, crystals could not be formed in the absorber, but could be formed in a crystallizer maintained at 10 °C, the optimal temperature for crystallization. The N/P ratio of the recovered crystals was 1.47, indicating that the crystals were a mixture of MAP and DAP. Analyses of SEM and XRD revealed that the recovered crystals were composed of MAP and DAP. |
Databáze: | OpenAIRE |
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