Effectiveness of aegle shell (AS) and groundnut shell (GS) as carbon sources for bio-denitrification of nitrate rich aqueous solution

Abstract

Many of the waste organic solid substances (WOSS) can be biologically degraded into smaller organic molecules that in turn can be used by the microbial community as carbon and energy sources. The attempt of this work aims at making the organic sources available to the denitrifying biomass, which in turn helps in removing nitrates from aqueous solution. In this study we have explored the effectiveness of many WOSS like sugarcane baggage (SB), coconut shell (CS), aegle shell (AS), groundnut shell (GS) etc. as carbon source and substrate for biomass attachment in biological denitrification process. Among the examined substances, AS and GS responded effectively both to the batch and continuous mode of denitrification experiments. The results of the batch test showed the denitrification efficiency to be 98% and 96.5%, while that of soluble chemical oxygen demand (SCOD) utilization being 87% and 97%, respectively for AS and GS. There was negligible amount of accumulation of nitrite and ammonium ions in both the cases. In continuous experiments the denitrification efficiency for AS and GS were found to be 98.5% and 96%, respectively. Negligible amounts of nitrite and ammonium accumulation and 100% SCOD utilization were other findings of continuous experiments. The results of this study advocates for the possible application of AS and GS, as carbon sources and substrates for biomass attachment in biological denitrification process. � 2016 American Scientific Publishers. All rights reserved.