Calcium Phosphate Precipitation as an Unintended Consequence of Phosphate Dosing to High-pH Water.

ABSTRACT: A calcium phosphate solid formed as an unintended consequence of a novel high-pH orthophosphate lead corrosion control strategy in Providence, RI, resulting in some consumer complaints and clogged plumbing. Investigations were carried out at pH levels of 8.9-10.4, at temperatures of 5-60°C, and with orthophosphate concentrations ranging from 0 to 4.0 μg/L as orthophosphate (PO₄) to examine this phenomenon. During field testing, the calcium phosphate initially precipitated at orthophosphate doses above about 2 mg/L as PO₄, and the extent of precipitation increased with water age and higher temperature. Laboratory-scale tests confirmed that doses above about 2 mg/L as PO₄ were required to form the precipitate in the absence of preexisting calcium phosphate so

SUBMITTER: Devine C 

PROVIDER: S-EPMC11998932 | biostudies-literature | 2024 May

REPOSITORIES: biostudies-literature