Evaluating the Effects of Polyphosphate Cartridge at Point-of-Entry on Scaling and Corrosion Indices of Household Water

Abstract

Scaling and corrosion are significant issues in water distribution systems that can lead to economic, aesthetic, and health concerns. This study aimed to investigate the effects of a point-of-entry (POE) polyphosphate cartridge on scaling and corrosion indices (Langelier Saturation Index [LSI], Ryznar Stability Index [RSI], Puckorius Scaling Index [PSI] and Aggressive Index [AI]), as well as the quality of water treated with household water treatment systems. In this study, a POE polyphosphate cartridge was directly connected to municipal water to adjust water stability and prevent scaling and corrosion. Parameters were tested in water samples before and after filtration with the POE polyphosphate cartridge. Spearman’s correlation analysis was conducted to determine any monotonic relationship between the variables using SPSS. It was observed that water exhibited scaling properties at flow rates of 0.180, 0.252, and 0.522 L/min based on the LSI, while in other cases, it showed corrosion properties. Additionally, the results of the Spearman analysis indicated a strong positive correlation (r=0.74) between RSI and PSI and a strong negative correlation (r=-0.64) between LSI and RSI in the outlet water from the POE polyphosphate cartridge. The results indicated that more precise control of key quality parameters for scaling and corrosion of water is essential. Significant adjustments must be implemented to prevent corrosion of facilities and valves when utilizing a POE polyphosphate cartridge in household water systems. Moreover, due to the fluctuations in household water consumption, the use of inline POE polyphosphate cartridges may not ensure water stability in the household water supply system.