Potential of Using Natural Materials as Support Media in Anaerobic Filter for Tapioca Wastewater Treatment

Abstract

Tapioca starch manufacturing generated a large amount of wastewater containing high organic matter contents. Wastewater from tapioca starch manufacturing thus had a high potential for biogas recovery. In Thailand, biogas recovery from tapioca wastewater has been performed via a UASB system for large-scale manufacturers and a cover lagoon system for small-to medium-scale manufacturers. Settling the UASB system on a tapioca starch processing site required high investment and operation cost, whilst settling the cover lagoon system required a land area. There were a number of studies identifying that the anaerobic filter system, using natural materials as support media, had a high efficiency for treatment and biogas recovery of agro-industrial wastewater containing high organic contents. This research was begun with the idea to seek for a proper technique for treatment and biogas recovery, with high effectiveness and low cost, of wastewater from small-to medium-scale tapioca production plants. The studied materials, used as support media, were two natural materials (burnt corn cobs and charcoal) and synthesis material (plastic balls). The research experiment has been undertaken, using three laboratory-scale anaerobic filter reactors. The initial findings have showed that wastewater treatment efficiencies, as well as biogas production capacities, of the two reactors containing selected natural support media types and the one containing synthesis media type were in the same range. The COD removal efficiencies were 95.42% to 97.90%. The SS removal efficiencies were 78.12% to 85.32%. The methane contents of biogas produced were 73.45% to 75.06%.