Detection of ( unusual ) changes in wastewater composition using UV / VIS spectroscopy

Using measurements of the whole UV/VIS spectrum enables to monitor changes in wastewater concentration as well as in wastewater composition. Operators of wastewater treatment plants benefit when changes of concentration and/or composition of industrial inlets can be detected and therefore a possible failure of the treatment plant performance can be avoided. The instrument used is a submersible UV/VIS spectrometer (spectro::lyser by s::can Messtechnik, Vienna) that utilises the whole UV/VIS range between 200 and 750 nm. With just one single instrument nitrate, organic matter and suspended solids can be measured simultaneously. The spectrometer is installed directly in the process and measures in real-time. It is equipped with a very effective auto-cleaning system using pressured air that enables measurements at the influent of a wastewater treatment plant or directly in the sewer for several weeks (> 4) without maintenance. The paper shows influent measurements at a wastewater treatment plant where significant changes in the wastewater composition occurred. Time series and fingerprints are shown that enabled a identification of wastewater composition changes and polluters.