Biostimulation of anaerobic digestion through microwave irradiation

This research investigated the effects of low energy microwave irradiation on a lab scale anaerobic digestion process. Distinct digesters were irradiated according to different treatment schedules with 0, 500, 750 or 1000 kJ/kg DS. It was found that the microwave treatment of digesters fed with kitchen waste influences the production of volatile fatty acids. An increase of the applied energy reduced the residual amount of butyric acid up to 99% compared to the control. However, the increase of the applied energy resulted in an increase of propionic acid by a maximum of 108% up to 3132 ppm. Microwave treatment of the digestion of thickened activated sludge resulted in an increased biogas production, up to 78%, and an improved biogas production rate.status: publishe