Cellular Automata-Based Mechanistic Model for Analyzing Microbial Regrowth and Trihalomethanes Formation in Water Distribution Systems

...For simplification, the bacterial cells’ organic carbon contents were approximated as 1 × 10−9 mg-C/CFU [10,11]....

...0 mg-C/L represents water with possible organic pollution [11]....

...The chlorine-induced mortality was modeled with second-order kinetics based on the concept of competing reactions in water [11]....

...A similar work, utilizing a Cellular Automata-based model (CA-MSRT model), was recently reported by [11]....

...The existing scientific knowledge was applied during the model development to define chlorine decay, NOM degradation, planktonic microbial regrowth, biofilm dynamics, and THM formation inside the distribution pipes....

...The MSRT model, implemented using the multi-species extension of EPANET (EPANET-MSX) [24], considers the advective transport and reactions of chlorine, NOM, microorganisms, and 2,4,6-TCP in WDSs. Simulations were conducted within two benchmark systems, and the resulted output includes concentrations of the relevant biotic and abiotic parameters signifying the physicochemical and biological interactions in WDSs....

...Recent research identified two independent pathways for 2,4,6-TCA formation [16]: chlorination of anisole in natural organic matter (NOM); microbial O-methylation of precursor 2,4,6-trichlorophenol (2,4,6-TCP)....

...Apart from SAM, the other methyl donors include methanol, methylamines, and methanethiol, which are amply present as NOM in the natural waters [20]....

...Yield coefficients were selected to represent THMs formation by chlorine reactions with NOM [25] and planktonic microorganisms [36]....