Biological activated carbon (BAC) filtration is an important treatment step in the production of drinking water especially if drinking water is produced from surface water. The performance and processes within a BAC filter have been of interest for researchers since the 1980's, mainly because of its ability to remove natural organic matter known as disinfection precursors. A malfunction of one of the pre-treatment steps might affect the feed water quality into the BAC filters. The main objective of this study was to determine the immediate response of the BAC filters to a rapid change in feed water quality. It was shown that with the studied setup it was possible to compare the effect of different pre-treatment steps and subsequent different water qualities on the performance of the BAC filters on the long term adaptation. However, especially the immediate response was not studied in detail before. All filters were able to mitigate a sudden change in feed water quality, either through improved adsorption or increased activity of the biomass on the filter. As a result of this resilience against sudden changes, it is therefore concluded that there is no direct need for very stringent on-line monitoring and continuous adjustments of the feed water quality of the BAC filters. The addition of phosphate resulted in the lowest dissolved organic carbon (DOC) concentration in the effluent of the BAC filters. In this study the influence of intact cells in the feed water on the performance of the BAC filters was shown to be limited.

A kinetic study has been performed on the degradation of furfural in a dilute acidic and saline solution with and without the presence of glucose. Experiments have been performed in a stirred batch reactor. The degradation of furfural alone was accurately predicted both using a first- and a second-order kinetic model. It was shown that furfural is degrading significantly faster when glucose is present in the reaction mixture. In the series with glucose present distinct second-order reaction kinetics were observed. From experiments with varying concentrations of glucose it turned out that an additional (second-order) reaction had to be added to the reaction mechanism in order to satisfactorily predict the experimental data. This additional reaction incorporated the initial glucose concentration as a constant in the Arrhenius expression for the reaction rate constant. Furthermore, it has been argued that this second-order reaction could well be a Diels-Alder reaction.