The dynamics of biofilm detachment from the pipe walls of drinking water distribution systems was investigated through experiments in a full-scale pipe loop laboratory system. Biofilms grown under steady-state and transitory flow rates were compared. Flow cytometry was used to quantify the microbial cells of the biofilms, and biofilm shear strength was evaluated based on their capacity to resist mobilization when subjected to elevated flushing flow rates. The results suggest that biofilms grown under transitory flow regimes may develop stronger adhesion strength to the pipe wall. This paper contributes to the enhanced understanding of biofilm behaviour in drinking water systems and its potential impacts on water quality.

Moderate hydraulic transients (∼20 kPa) enhanced biofilm growth/adhesion; stronger ones caused detachment but created resilient films. Small transients shaped biofilm distribution in water pipes, proving flow variability drives microbial stability.

An indicator that correlates physical quantities with water quality has great relevance for the definition of projects and understanding of real hydraulic transient phenomena. The work proposing a method to estimate water quality in real system focusing on turbidity measurements during a transient, as surrogate to understand potential dynamics in real systems. In order to get an empirical formula to turbidity during hydraulic transients, was observed 5 years’ data from a real system. This system is one of the mains important pipelines of the Water Supply System of Curitiba and Metropolitan Region, in South Brazil.

This research explores the influence of chronic, small-amplitude hydraulic transients on biofilm development within water distribution systems (WDSs). Utilizing a unique experimental setup, it contrasts the biofilm dynamics under steady and transient hydraulic conditions. Findings reveal biofilms developed by transient conditions notably enhance adhesion and resistance to flushing, challenging the conventional focus on steady-state hydraulic scenarios. The research underscores the importance of integrating transient hydraulic effects into water distribution system management and design, to improve water quality and system integrity.

This paper presents an analysis of the challenges associated with discoloration risk management and the impact of hydraulic transients on water quality within distribution systems. Focusing on the Metropolitan Region of Curitiba, Paraná, Brazil, the study employs a comprehensive methodology that combines the Characteristic Method for simulating hydraulic transients and real-time monitoring of water quality parameters, such as turbidity and chlorine levels. A framework for managing discoloration risk is proposed, highlighting strategies for identifying potential causes, assessing risk severity, developing prevention and mitigation strategies, and implementing continuous improvement processes. The experimental section details the impact of hydraulic transient events on water quality, with significant findings indicating a direct correlation between flow dynamics and water quality degradation, particularly in terms of increased turbidity and decreased chlorine levels during pump deactivation. The study contributes valuable insights into effective water distribution system management, emphasizing the importance of advanced monitoring and risk management techniques to maintain high-quality water standards.

This research explores the microbial ecology within drinking water distribution systems (DWDS). The aim of the paper was to examine the impact of small-amplitude transients on the bacterial composition in bulk water and biofilms. The findings highlight the dominance of Proteobacteria and the significant transformation of microbial communities in response to changes in environmental conditions. The study underscores the complex interplay between operational strategies and microbial dynamics in DWDS and emphasizes the necessity for ongoing research to enhance water quality management amidst climate change challenges.