Surendra Kumar^1,, Omprakash Sahu¹

Treatment of gound waste water by biological denitrification experiment was conducted using sugar industry wastes, namely final molasses as a carbon source and bagasse charcoal pellets as supporting media for denitrifying bacteria.We employed an upflow fixed-bed reactor filled with the pellets and biofilm attached onto them.This was fed with potassium-nitrate and dilute-molasses solutions.Total nitrogen removals of more than 85 % were achieved at influent carbon-nitrogenratios between 2 and 4, and hydraulic residence times of more than 0.8 (h).This demonstrated final molasses could be used as an alternative carbon source.On the other hand, final molasses also contained some organic/ammonium nitrogen and refractory organic matter including colors, both of which were difficult to remove with the reactor.Accordingly, at higher C/N ratios, these substances caused major increases in effluent total-nitrogen and organic-carbon concentrations.Therefore an optimum C/N ratio was found to be around 2.

coagulating, dissolved, settling, treatment