BIOLOGICAL GROUNDWATER DENITRIFICATION: LABSCALE STUDY OF THREE DIFFERENTE ORGANIC SUBSTRATES

Abstract

The intensive use of nitrogen based fertilizers represents the main cause of diffused pollution in groundwater. For this reason, in situ biological groundwater denitrification, coupling good removal efficiency and low operational cost, have obtained up to nowadays an increasing interest from researchers communities.

The paper reports the results of a lab-scale investigation, concerning the heterotrophic biological denitrification, sustained by three different carbon source: pine bark, cork and olive pomace. The experimentation has been divided into two phases: the former, focused to investigates the carbon sources features as well as the effective biodegradation capability, carried up in batch; the second carried out by means of lab-scale column continuously fed by water artificially contaminated with nitrates. The achieved results have shown good removal efficiency and also significant differences in kinetics have been highlighted. Particularly, olive pomace was the organic substrate capable to promote the best denitrification performances.