Denitrification of groundwater using Brewer's spent grain as biofilter media

This study evaluated Brewer's spent grain as media for denitrification processes in treating groundwater. A laboratory scale reactor was inoculated with anaerobic sludge from a waste-water treatment plant. Optimization of running conditions were investigated under various parameters including: hydraulic retention time (HRT), influent nitrate loading and pH. The experimental results demonstrate that the optimum reaction parameters were: HRT = 100 min; N-NO3 = 200 mg L−1; pH = 7.5–7.9. Vertical study showed that hydraulic retention time and pH affect significantly the nitrate removal, while nitrate loading do not affect the denitrification process.

► Brewer's spent grain was used as media for denitrification processes in treating groundwater. ► Optimization of running conditions was investigated under various parameters. ► Optimum reaction parameters were: HRT = 100 min; N-NO3 = 200 mg L−1; pH = 7.5–7.9. ► Results showed that hydraulic retention time and pH affect significantly the nitrate removal.