Heterotrophic denitrification of contaminated groundwater using arachis hypogaea. l shell as carbon source

Abstract

In this research, agricultural waste, Arachis hypogaea.L shells (peanut shells) was investigated for use as carbon source and biofilm carrier to remove nitrate from groundwater in batch reactor laboratory. The feasibility of heterotrophic denitrification of a high nitrate concentration groundwater using a natural carbon source was studied, a series of batch tests was performed with synthetic groundwater to exanimate the effects of various environmental and operational factors such as temperature, pH, initial nitrate concentration and finally the mass of powder of Arachis hypogaea.L shells on the rate of heterotrophic denitrification. A range of physic chemical analysis was performed including: Infrared, granulometry, spectroscopy atomic absorption and Scanning Electron Microscope (SEM).Decreasing initial pH decreased denitrification; however, increasing pH had little effect on denitrification rates. Using Arachis hypogaea.L shells as organic substratum of varying size classes, we found that finer-graine showed higher rates of denitrification compared to large grains, likely due to increased surface area per volume of substratum.Our findings suggest that Arachis hypogaea.L shell play an important role in N removal because they gave a reduction percentage of 90%