Abstract
The quality of water transported through freshly cemented water pipes depends not only on the type of cement used. The other factor affecting the degree of leaching pollutants from cement coatings is the chemical parameters of the water. A disinfection process is necessary for maintaining water which is safe for human health and high quality. However, simultaneously, the presence of disinfectant in water may cause some problems. The results of the experiments performed showed that independently of the concentration of sodium hypochlorite in water, rapid changes of water pH soon after cement mortar lining renovation may always be expected. The addition of disinfectant to water causes an increase in pollutants leaching from cement coatings, even in the case of a low disinfectant dose. Although the concentration of disinfectant in water has a differential impact on the degree of pollutants leaching from cement coatings, the increase in the leaching of the pollutants is not proportional to the disinfectant concentration.
Highlights
Many research papers report the various impacts of differ‐ ent cement types used for cement mortar lining renova‐ tion on the quality of transported water
Based on the measured element concentrations in the water and based on Eqs. (1) and (2) [27], it was possible to count the chemical elements leaching from the 1 m2 of cement coating surface area after contact with the chlo‐ rinated waters and with the water with no disinfectant (Fig. 3)
It can be stated that the concentration of disinfectant in water has no meaningful impact on the degree of pH changes which take place soon after renovation of the cement lin‐ ing
Summary
Many research papers report the various impacts of differ‐ ent cement types used for cement mortar lining renova‐ tion on the quality of transported water. It is known that among the many different factors, secondary water contamination depends on the chemical and biological quality of this water. Considering the impact of some quality parameters of water produced in water treatment plants on secondary water contamination, in this paper, an analysis and com‐ parison of the leaching of pollutants from cement coatings into three disinfected waters were performed. Because chemically instable water leads to the leaching of com‐ ponents from new concrete structures, it was decided to analyse whether any other factors, such as disinfectant concentration in water, affect the leaching of pol‐ lutants directly after cement lining renovation. Based on some analysed research papers [20,21,22], it can be supposed that when in contact with hardened cement mortar, disinfected water shows a different aggressiveness in relation to the cement compounds in comparison with disinfectant-free water. As Polish regulation [25] determines, the limitation value for free chlorine or chloramines in drink‐ ing tap water is 0.30 mg Cl2/dm and 0.50 mg Cl2/dm, respectively
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have