Nitrification and denitrification using a single biofilter packed with granular sulfur

This study was performed to develop a granular sulfur packed nitrification/denitrification process employing a uniquely designed single biofilter, which treated a relatively low carbon loaded domestic wastewater taken from a primary clarifier at a municipal wastewater treatment facility. The system was tested on varying experimental conditions, e.g. inflow flow, organic load and nitrogen load. Regardless of flow rate being increased, SS and COD was unvaryingly removed up to 90 and 80%, respectively. Moreover, TKN was also decomposed up to 90%. Increase in COD load gradually led to escalating level of non-biodegradable compounds observed in effluent. Nitrification was accomplished as high as 92%, whereas denitrification was achieved up to approximately 87%. For a while, nitrification and denitrification were observed at 0.65 and 0.55 kg/m³áday, respectively. Eventually, T-N was decomposed as high as 46%. It was concluded that granular sulfur can be used for not only electron donor, but also for a media to properly treat low carbon loaded wastewater and to filter SS efficiently.