Assessing comprehensive performance of biofilm formation and water quality in drinking water distribution systems

Environmental fluctuations shape biofilm formation in drinking water distribution systems (DWDSs) and therefore distributed water quality. Yet the comprehensive performance in response to complex environmental conditions remains unclear. We investigated biofilm formation and distributed water quality under various nutrients, including chlorine concentrations and hydrodynamic conditions. Results showed that environmental fluctuations collectively induced changes in microbial propagation, which were mostly associated with turbidity variations, concentrations of total organic carbon, NH4+-N and soluble phosphorus compared to the other parameters. Fuzzy pattern recognition analysis integrating multiple water quality indicators revealed that low nutrient availability and addition of mild chlorine at 0.50 mg/L at 0.50 m/s flow velocity were the most favorable conditions screened for optimized comprehensive performance, while nutrient supplements yielded significant performance deterioration. These quantitative estimations offer new insights into advanced understanding of the system performance responding to often complex environmental fluctuations, essential for optimized design and practical functioning of DWDSs.