New Methods for Microbiological Monitoring at Riverbank Filtration Sites

Abstract

Water suppliers aim to achieve microbiological stability throughout their supply system by regular monitoring of water quality. Monitoring temporal biomass dynamics at high frequency is time consuming due to the labor-intensive nature and limitations of conventional, cultivation-based detection methods. The goal of this study was to assess the value of new rapid monitoring methods for quantifying and characterizing dynamic fluctuations in bacterial biomass. Using flow cytometry and two precise enzymatic detection methods, bacterial biomass-related parameters were monitored at three riverbank filtration sites. Additionally, the treatment capacity of an ultrafiltration pilot plant was researched using online flow-cytometry. The results provide insights into microbiological quality of treated water and emphasize the value of rapid, easy and sensitive alternatives to traditional bacterial monitoring techniques.

Managed Aquifer Recharge for Water Resilience

“…Measuring bacterial biomass concentration and enzymatic activity is an innovative way of improving understanding of these processes. Adomat et al [22] did this using flow cytometry and two precise enzymatic detection methods to monitor dynamic fluctuations in bacterial biomass at three riverbank filtration sites. They also performed online flow cytometry in an ultrafiltration pilot plant.…”

Optimizing short time-step monitoring and management strategies using environmental tracers at flood-affected bank filtration sites

“…Near real-time monitoring technologies for the detection of microbial indicators via fluorescence-based methods, such as flow cytometry (Clausen et al, 2018) or enzymatic activity (Burnet et al, 2019), are in development and might in the future provide additional information at a proper timescale. Adomat et al (2020) assessed the Journal Pre-proof J o u r n a l P r e -p r o o f biomass dynamics at high resolution at three BF sites via flow cytometry and enzymatic detection methods. While such monitoring was shown to enhance the understanding of microbiological dynamics of the treated water at BF sites, they reported some divergence between the results due to methodological limitations.…”

“…As a result, water quality management decisions for the operation of BF systems and post-treatment are typically based on weekly to monthly time-step assays. In addition, Adomat et al (2020) recently evidenced short timescale bacterial fluctuations during a high temporal resolution monitoring at an ultrafiltration pilot plant and hypothesized a control by rainfall events and/or potential changes in surface water origin. To correctly interpret these variations, the authors highlighted the need to assess for "abiotic" parameters (i.e., EC, pH, dissolved oxygen) which can help to identify the processes controlling microbiological water quality.…”