Abstract
The ever-increasing need for high-quality drinking and process waters, and growing public awareness about possible contamination, drive efforts for the further development of automated control of water treatment plants. For example, membrane filtration processes and reverse osmosis in particular are generally regarded as a safe barrier for inorganic, organic, and microbial contamination. Yet, to ensure the final water quality and to increase the confidence of the end-user, intensive and preferably online monitoring should be further implemented as an early-warning tool to control membrane integrity and to prevent microbial regrowth in the distributing network. In this paper, we test the applicability of flow cytometry and cytometric fingerprinting for a full-scale water treatment plant. We demonstrate in a full-scale water treatment plant that flow cytometry can be used as online monitoring tool and that changes in water quality can be observed, which are not monitored by commonly used online quality parameters. Furthermore, we illustrate with ultrafiltration that process conditions impact the flow cytometric cell counts.
Highlights
Bacteria in water are an important aspect of the water quality and may, when present in too high concentrations, lead to biofouling, microbiologically induced corrosion or even the spreading of pathogens
In the full-scale water treatment plant, the incoming surface water was monitored after passing through 300 μm self-cleaning strainers prior to the ultrafiltration step (Fig. 1)
Neither the peaks in the cell concentration measured by flow cytometry nor the peaks in feed water turbidity resulted in an increased conductivity (Fig. 2c)
Summary
Bacteria in water are an important aspect of the water quality and may, when present in too high concentrations, lead to biofouling, microbiologically induced corrosion or even the spreading of pathogens. Open cooling water systems provide a favorable environment for microorganisms because they scrub microorganisms from the air and concentrate the nutrients present in remaining water by evaporation, resulting in faster microbial growth.[2] Biofilms can damage equipment through microbial induced corrosion (MIC), by clogging, and lead to an increased energy consumption due to decreased heat transfer.[3,4] Biofouling and clogging leads to an increased pressure drop in ion exchangers and to increased resistance in membrane filters, which may cause membrane breakthrough.[5] pathogenic bacteria can nestle in these biofilms and contaminate the water through the natural shedding cycle of biofilms.[6] A well-known example is the spreading of the pathogen Legionella pneumophila in the form of aerosols.[7,8] Membrane processes such as microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) are commonly used in water treatment, including reuse applications.[9] MF is designed to retain most bacteria and suspended solids in the range of 0.1 to 5 μm. Our results illustrate the possible application of flow cytometry for microbial quality assurance and as tool to control membrane filtration processes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
