Both national laws and an increasing number of supranational recommendations are prescribing emission limits for waste-water treatment plants (WWTP). In order to be able to control maximum run-off concentrations, for instance, frequent sampling of inﬂuent and efﬂuent at WWTP is still usual.
Furthermore, the pollution of waste water at many stages of the treatment process must be determined for purposes of inﬂuencing operation and/or control and thus optimizing treatment performance, and thereby minimizing costs and the use of resources, and also optimizing the protection of our environment. For this purpose, it is widely accepted today that substances and substance groups in waste waters should be monitored:
2. without delay (in “real time”)
This is the only way allowing quick reaction to changes in waste-water composition or operational conditions.
Online measurement in waste water using photometric instruments for individual wavelengths, a state-of-the-art technique for some years now, has proved its value – however, only following sophisticated on-site calibration, just for single parameters so far, and often prone to cross-sensitivities.
The spectrometer probes from s::can use the same measuring principle: the absorption of light. Yet they measure not only one or two wave lengths, they measure the a continuous optical spectrum reaching from low ultraviolet to visible light.
This ﬁngerprint contains much more information about the water quality than a single wavelength instrument can provide, allowing more accurate and universal measurements.
The brand-new s::can analyzers can be directly immersed into the medium, making it possible for the ﬁrst time to combine the advantages of in-situ measurement with those of spectrometry, eliminating such well-known drawbacks as sampling errors, biochemical or physical degradation, etc.