Comparison of chlorination and chloramination practices on microbial inactivation efficiencies within a scaled‐up water distribution network using central composite design

Abstract

Disinfection practices reduce the incidence of water‐borne diseases but may result in formation of disinfection byproducts (DBPs) in raw water that are reported to be carcinogenic. Central composite design (CCD) was employed in the present study for optimization of disinfectant dose and contact time with the rationale to evaluate if an optimal balance could be achieved between minimal DBPs formation and effective microbial inactivation with either free or combined chlorine in treated water within a lab‐scale prototype network to simulate real water distribution network conditions. After a series of experimental runs based upon design of experiments (DoE) by CCD, dose was found to be the most significant factor (P < 0.01) in determining DBPs formation in both disinfectant’s applications. Where, contact time significantly (P < 0.01) affected bacterial inactivation in chlorination experiments, in contrast, dose was effective in chloramination experiments. Thus, it was concluded that the optimal balance may be achieved in the water networks with the help of multifactorial optimization when disinfectant dose was maintained near 3 mg/L as applied chlorine dose in both disinfection cases, while contact time was 62 and 155 min for chlorine and chloramine, respectively.

Modeling the content of chloroform in drinking water infiltration intake by periods of the annual cycle: low-water and permanent watercourse

“…This article presents the results of statistical modeling. The main task of modeling is to assess the change in the drinking water quality when conditions change in the catchment area and to assess the likelihood of events occurrence that pose a threat to the water supply system (in terms of drinking water quality) [3][4][5][6][7].…”