Rice Industry Waste as Wastewater Treatment

Salman Mo. Tabani[1] , Omprakash Sahu[2]
Page No. 119-127

Treatment of waste water by biological denitrification experiment was conducted using rice
industry wastes, namely final husk-2 as a carbon source and husk 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-husk-2 solutions.
Total nitrogen removals of more than 85 % were achieved at influent carbon-nitrogen ratios
between 2 and 4, and hydraulic residence times of more than 0.8 (h). This demonstrated final husk-
2 could be used as an alternative carbon source. On the other hand, final husk-2 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.
Keywords: Absorption; Coagulating; Dissolved; Settling; Treatment