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Ion‐exchange softening of human urine to control precipitation
Author(s) -
Boyer Treavor H.,
Taylor Kyle,
Reed Alesandra,
Smith Daniel
Publication year - 2014
Publication title -
environmental progress and sustainable energy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.495
H-Index - 66
eISSN - 1944-7450
pISSN - 1944-7442
DOI - 10.1002/ep.11825
Subject(s) - struvite , chemistry , precipitation , urine , ion exchange , amberlite , hydrolysis , magnesium , ion exchange resin , chromatography , inorganic chemistry , nuclear chemistry , ion , adsorption , biochemistry , organic chemistry , physics , meteorology
A major barrier to widespread implementation of urine source‐separation is the uncontrolled precipitation of magnesium (Mg) and calcium (Ca) minerals in waterless urinal plumbing, which results in clogging that increases maintenance requirements. The goal of this research was to investigate the use of ion‐exchange softening of undiluted, fresh human urine to control precipitation reactions in hydrolyzed urine. The working hypothesis was that selective removal of Ca and Mg from undiluted, fresh urine by cation exchange resin would decrease the precipitation of Ca and Mg minerals in hydrolyzed urine. Ion‐exchange experiments and precipitation experiments were used to investigate ion‐exchange reactions in synthetic urine. Cation exchange resin (Amberlite A200C) removed both Ca and Mg from undiluted, fresh urine with a greater affinity for Ca over Mg. Precipitation experiments showed that struvite, MgNH 4 PO 4 ·6H 2 O, and hydroxyapatite, Ca 5 (PO 4 ) 3 (OH), were the dominant minerals in untreated and ion‐exchange treated hydrolyzed urine. Overall, ion‐exchange softening decreased the mass of solids that would be deposited in the urinal plumbing and increased the phosphate available for nutrient recovery. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 564–571, 2014