Recovery of struvite from animal wastewater and its nutrient leaching loss in soil

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• 作者：Md M. Rahman^a ; YingHao Liu^a ; Jung-Hoon Kwag^b ; ChangSix Ra^a ; ^{changsix@kangwon.ac.kr}
• 关键词：Magnesium ammonium phosphate (MAP) ; Swine wastewater ; Leaching loss
• 刊名：Journal of Hazardous Materials
• 出版年：2011
• 出版时间：28 February 2011
• 年：2011
• 卷：186
• 期：2-3
• 页码：2026-2030
• 全文大小：376 K

文摘

Contaminants in swine wastewater were recovered in the form of struvite, a crystal of magnesium ammonium phosphate (MAP), using a newly designed process, and the leaching loss of MAP in soil was examined. The continuous flow process was operated under optimal conditions: 1.0 molar ratio of magnesium (Mg) addition with respect to orthophosphate (OP) and an aeration rate of 0.73 L/L min. Five treatments were performed with three replications for soil pH and nutrient leaching loss tests. It was found that 93 % of the OP in the swine wastewater was crystallized, and the MAP crystal formation was verified by X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses. The analyses revealed that the pattern of pH change and N leaching losses for MAP-treated soil were remarkably different from those for fused super phosphate (FSP)-urea-treated soils. The pH levels for the control and FSP-urea-treated soils after a five-week experiment were unchanged or slightly decreased, whereas an increase in pH was observed in the MAP-treated soils. Leaching loss of N was higher in FSP-urea treatments, with MAP treatments showing N losses of only 1.93 and 2.05 % , respectively, while FSP-urea treatments showed N losses of 7.82 and 6.47 % , respectively, during the same period. Phosphate (P) leaching was very slow in both MAP- and FSP-treated groups.