Intensification of Activated Sludge Waste Water Treatment

The efficiency of two possible intensification methods of activated sludge waste water treatment (pure oxygen activation and activated carbon addition) were compared. Experiments were carried out in laboratory scale equipment with variable reactor volume (maximum capacity 20,0 dm3, settling tank vol. 15 dm3). In order to detect even minor differences, we operated completely identical units in parallel runs, with one representing a traditional system as reference. A model sewage of industrial character, diluted milk, was used as influent and in the course of activated carbon intensification experiments an anion-active detergent was added as a poorly biodegradable model material to be removed mainly by adsorption. Reactor loads were gradually increased - from low values to overloading - by decreasing the dilution of milk or by reducing reactor volume. The effects of different intensification methods on the effluent pollution level (COD value and anion-active detergent content) and on the settling properties of sludge were examined as a function of loading. The efficiency of both intensification methods was found to be increasing with increasing loading. Comparison of the two systems showed activated carbon intensification to be more efficient in the removal of soluble COD and extremely useful in the elimination of a poorly biodegradable material.