A comparative study of portland cements CEM I used for water pipe renovation in terms of pollutants leaching from cement coatings and their impact on water quality

Obtained EDS and ICP elemental analyses results showed some small differences between the compositions of two of the most common Portland cements, CEM I types, used for water pipe renovation. An evident link between the cements' composition and total amounts of leached elements from tested cement coatings was observed. The performed experiments confirmed that the greatest risk of water contamination soon after pipe renovation by cement mortar lining is related to aluminium leaching. As it turns out, the degree of aluminium leaching from cements produced by two different manufacturers is indicated to be very similar, in comparison to the leaching of calcium compounds and some trace elements. In both cases, the pollutants leaching from the cement coatings into water is most intensive in the initial period of contact and decreases over time. Despite some differences between the calculated concentrations of chemical elements in water, especially lead and chromium, in most cases, their estimated concentrations at the outflow from freshly renovated pipelines cemented with different Portland cements CEM I types and for different pipe diameters, lengths and water flow velocities were much lower than the maximum permissible levels in drinking water.