Denitrification of groundwater with elemental sulfur.

Autotrophic denitrification was studied in laboratory columns packed with granular elemental sulfur only and operated in an upflow mode. Soluble inorganic carbon, sodium bicarbonate, was supplied as source of carbon for microbial growth. Denitrification rates of up to 0.20 kg N removed m(-3) d(-1) were obtained at a hydraulic retention time of I h, and a nitrate loading of 0.24 kg N m(-3) d(-1). The process is extremely simple, stable and easy to maintain.