Use of ultraviolet (UV) absorption for control of adsorption processes.

Summarizing all the available experience from different types of investigations, the following conclusions can be made: 1. UV-absorbance has proved useful as a control parameter for granular activated carbon filter performance. It is very easy to measure and very often runs parallel with other more significant but more difficult-to-measure criteria, such as dissolved organic chlorine. 2. Generally speaking, UV-absorbance can be used in those cases where parallel tests using other parameters and analytical methods have shown that the UV data correlate sufficiently well with other more important criteria. This is often, although not always, the case. There may be exceptions, for instance if the removal of pure substances like haloforms in small concentration is crucial for the carbon filter operation. 3. In most cases, carbon filter control can best be done by using a convenient method, such as UV-absorbance, for routine control of the filters and by comparing these data from time to time with the results of other more sophisticated methods. This will allow conclusions from easily obtainable data and will give information in such a short time that special tests could be made in case of unusual values and relationships. In this respect, UV-absorbance measurements can be worthwhile and helpful for carbon filter control.