Bio-Retentive Properties of Synthetic Media for Anaerobic Digestion of Animal Waste

The results from a three-year study involving three types of synthetic media for process intensification of anaerobic digestion of swine waste are reported. The three media types were a polyurethane foam, a woven nylon mesh and a polypropylene felt. The physical durability of the different media for the three six-month runs and the ability of each media type to retain bacterial growth within the reactors are reported. Evaluation of the three media types showed that the polyurethane foam material was effective in retaining bacterial culture, but was subject to physical degradation in a mixed reactor environment, and approximately 98% of the original media was lost during the study. The woven nylon mesh was extremely durable but its bio-retentive characteristics were the lowest of the three types. The polypropylene felt proved to be the best media material, showing good physical durability (i.e., no breakdown or loss) and excellent bio-retentive properties.