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ABSTRACT Research has demonstrated that water quality degrades in commercial and institutional (C&I) building premise plumbing leading to increased risk to consumers. This study aimed to bridge the gap between real premise plumbing systems and theory by using a pilot scale pipe rig representative of C&I premise plumbing. The research examined changes in key water quality parameters, including chlorine, copper, trihalomethanes (THMs), and cellular ATP (cATP) across different flushing and stagnation conditions. Results indicated significant degradation during periods of stagnation found in real premise plumbing, with reductions in chlorine levels and increases in copper and THM concentrations. Conversely, flushing effectively renewed water quality, though the extent varied with system size and flow dynamics. Correlations were found between key water quality variables. The findings emphasize the need for strategic water management practices to mitigate risks associated with poor water quality in building plumbing systems. 

Abstract Human urine is a readily available nutrient source that can complement commercial fertilizer production, which relies on finite mineral resources and global supply chains. This study evaluated the effectiveness of a simplified solar distillation process for urine to recover phosphorus (P) and nitrogen for agricultural use and water for non-potable purposes. Synthetic fresh, synthetic hydrolyzed, real fresh, and real hydrolyzed urine were exposed to direct sunlight for 6 h in a simple distillation apparatus, which produced distillation bottoms and distillate. Metal phosphate precipitation in the distillation bottoms was evaluated to recover P. The non-potable water was recovered as distillate. Hydrolyzed urine recovered more metal phosphate solid in the distillation bottoms and had a higher conductivity in the distillate than fresh urine. Hydrolyzed urine also achieved greater distillate volume recovery than fresh urine. Hydrolyzed urine had a greater presence of UV-absorbing organics in the distillate than fresh urine and therefore produced a lower-quality product water. There was no significant correlation between the daily high air temperature and the volume of distillate recovered. This study provides a comprehensive data set on simplified solar distillation of human urine considering the fate of nutrients and water for different types of urine.