MULTI-ReUse 2 – Monitoring in Water ReUse

The flow cytometry allows to measure both total and intact cell populations online and offline. Flow cytometry offers fast and reliable determination of bacterial cell numbers in the field of monitoring water reuse processes. Based on the fact that the detection isn’t based on the cultivation of the bacteria, the entire bacterial population in the water is measured independent of their growth requirements. While traditional hygienic indicator bacteria such as coliforms, intestinal enterococci or clostridium perfringens are typically not detectable after membrane filtration and total colony counts are only available after 2–3 days, flow cytometry offers a sound data base for the microbiological assessment of the efficiency of different water treatment steps. Information about the actual microbiological status of a water sample, i.e. about total and intact cell concentration, is supplemented by information about the microbiological growth potential and therefore indirectly about the assimilable organic nutrients contained in the water.

“Reverse Isotope Labeling” (RIL) is a new method to determine the biodegradable dissolved organic carbon (BDOC). The new RIL method provides a sensitive and easy to handle method for the determination of the BDOC and delivers comparable results with precise specifications of concentrations. It measures the biological stability of the treated water and indicates when the BDOC reaches levels where measures for risk minimization need to be taken.