Examining the Effects of the Runoff Originating From Biosolids Amended Soil Plots on the Biogeochemical Nitrogen Cycle and Eutrophication
thesisposted on 23.05.2021, 10:58 by Denis Matiichine
One of the disposal methods for biosolids (nutrient rich organic matter that settles out of the wastewater during wastewater treatment process) is through application on agricultural fields as organic fertilizer. In order to determine the effects of runoff originating from biosolids treated fields on the nitrogen biogeochemical cycle and eutrophication of surface water, a lab-scale mesocosm experiment was carried out, simulating agricultural fields and thermally stratified water systems receiving agricultural runoff. A significant difference was found between the effects of the runoff from unfertilized soil plots and plots fertilized with biosolids. The findings indicate that the majority of incoming nitrogen is either denitrifed, lost to the sediment or is accumulated in the water column as nitrate. Further, it is hypothesised that the majority of incoming organic nitrogen was rapidly mineralized to ammonium in the hypolimnion, which has the potential to increase nitrogen bioavailability to primary producers in the epilimnion.