Chemical and microbiological risk-based optimization of disinfection and monitoring: a meta-model approach

The proper operation of drinking water distribution networks (DWDN) requires an optimal equilibrium between chemical and microbiological risk. In disinfected DWDNs a trade-off needs to be found in setting the concentration of residual disinfectant at the outlet of the drinking water treatment plant (DWTP) to simultaneously minimize bacterial regrowth and disinfection by-products (DBPs) formation. Since, support tools for such optimization are missing, the goal of our study was to develop a meta-model to link the disinfection operating parameters with microbiological and chemical water quality parameters. This was achieved through three steps: (i) analysis of monitoring data provided by an Italian water utility referred to 27 DWTPs; (ii) design and performing of monitoring campaigns in four DWTPs, selected as representative from the data analysis; (iii) development of a meta-model, built with data collected during monitoring campaigns.