OLIVE NUT AS BIOTRENCH CARBON SOURCE FOR BIOLOGICAL GROUNDWATER DENITRIFICATION

Abstract

In-situ treatment of nitrates contaminated plumes by means of biotrench, filled with materials able to promote the biological denitrification, is nowadays considered as an affordable alternative among the possible applicable technologies. Previous studies highlighted that olive nut, due to its high content of organic carbon as well as of lignin, resulted capable to promote significant removal efficiency. The paper reports the results of an experimental lab scale study carried out with a column filled with a blend of olive nut, sand and soil and feed in continuous with water artificially spiked with nitrates concentration up to 35 mgNO3-N L-1. Despite the low hydraulic retention time the denitrification efficiency resulted very high (up to 99%). Furthermore, the nitrous oxide production was investigated during the experimentation in order to assess the contribution of a such technology to the production of greenhouse gas.