title: Fate of phosphorus in diluted urine with tap water.
abstract: P loss during the fresh urine storage process is inevitable because of the presence of Ca and Mg. Dilution is one of the most important parameters influencing urine composition and subsequent P recovery. This study aimed to investigate the fate of P in urine with different dilution ratios (Vwater/Vurine, i.e., 0/100, 25/75, 50/50 and 75/25). The results indicate that the percentage of P loss increased from 43% to 76% as the dilution ratio increased from 0/100 to 75/25 because of more Ca and Mg obtained from tap water. Meanwhile, P removal efficiency through struvite precipitation decreased from 51% to 8% because of lower supersaturation ratio as a result of dilution. Struvite crystals with high purity were still obtained even under a dilution ratio of 50/50 urine solution. Batch experiments were also performed to study the influence of temperature (15-35°C) on P recovery and crystal size. For different dilution ratios of urine solutions, no significant discrepancy for the P removal efficiencies were observed at 15 and 35°C, whereas the P removal efficiencies at 25°C showed an increasing gap with those at 15 and 35°C. The largest average crystal sizes were found at 25°C, which was opposite to the trend of P removal efficiency.
authors: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Xiaoning
authors: X
authors: Liu
authors: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Guoqi
authors: G
authors: Wen
authors: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Huihui
authors: H
authors: Wang
authors: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Xiaoqi
authors: X
authors: Zhu
authors: College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: zhyhu@ucas.ac.cn.
authors: Zhengyi
authors: Z
authors: Hu
mesh_terms: D002118:Calcium; D003460:Crystallization / Q000379:methods*; D006801:Humans; D008274:Magnesium; D017616:Magnesium Compounds / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis / Q000737:chemistry*; D013048:Specimen Handling / Q000379:methods*; D000069877:Struvite; D013696:Temperature; D014556:Urine / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D017616:Magnesium Compounds; D010710:Phosphates; D014867:Water; D010758:Phosphorus; D000069877:Struvite; D008274:Magnesium; D002118:Calcium
keywords: Dilution; Phosphorus; Struvite; Temperature; Urine