Effect of the feed frequency on the performance of anaerobic filters

Anaerobic filter technology is suitable for the treatment of biodegradable organic wastes: for example, wastewaters from food industries. These wastewaters are not produced in a continuous mode since they are of seasonal nature and hence their production varies considerably during the year. In this work, a study of the performance of anaerobic filters with changing feeding systems was undertaken. A comparison was made between continuous feeding and different semicontinuous modes of feeding (in which the overall volume to be added into the reactors was divided into several doses and each of them were added at a constant interval of time). Filter performance was characterized by determining the different operational variables: depurative efficiency, methane production, biogas composition and volatile acids. From the obtained results, we conclude that the optimum feed frequency range is 24 doses/day or more. The continuously fed system has both greater stability and degradation efficiency.