The influence of environmental condition on precipitates from urine

Abstract

The influence of flushing water on the precipitate formation from urine in drainpipes was investigated. In the case of using flush water, hydroxylapatite and amorphous calcium phosphates were precipitated as rigid scale on the surface of drainpipe. In contrast, in the case of waterless condition, struvite was precipitated in gel-like matrix composed of amorphous calcium phosphates and organic compounds, resulting from high concentration of urine and high pH. It is suggested that the waterless condition prevents the formation of rigid scale on the surface of the drainpipe.