TITLE:
Impact of Water Chemistry on Lead Carbonate Dissolution in Drinking Water Distribution Systems
AUTHORS:
Maryam Mohammadzadeh, Onita D. Basu, Jose E. Herrera
KEYWORDS:
Hydrocerussite, Cerussite, Lead Dissolution, Cold Temperature
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.7 No.5,
March
25,
2015
ABSTRACT: Elemental
lead is a known toxic metal that can pose threats to human health and can be
found in a variety of sources including drinking water at very low level
concentrations (i.e. μg/L range).
Destabilization of the corrosion scale at the inner layer of pipeline is the
major source of lead in drinking water. Chemical properties of the water
passing through the distribution system such as pH, alkalinity, chlorine
content, oxidation reduction potential (ORP) and natural organic matters will
affect the formation and/or destabilization of the corrosion scale. This
research examines the impact of pH values (7.0 - 9.5), temperatures (5°C vs
20°C) and alkalinity levels (moderate vs low), in the presence of chlorine, on
dissolution of hydrocerussite and cerussite in drinking water by various sets
of batch dissolution experiments. The results showed dissolution of cerussite
and hydrocerussite was not impacted significantly by pH ranging 7.0 - 9.5. In
addition, and somewhat surprisingly, cold temperature (5°C) and moderate
alkalinity showed a great influence on decreasing the solubility of lead
species.