The fate and transport of pathogens introduced by artificial groundwater recharge at the Nardò fractured aquifer in Salento, Italy is investigated. Wastewater effluents from a municipal treatment plant with known pathogen concentrations were injected into a sinkhole and the migration of pathogens in the fractured aquifer was monitored at three sampling wells. The fate of pathogens was quantified by a mathematical model describing colloid transport in a set of three-dimensional, parallel fractures with spatially variable aperture. The number of parallel fractures and their average fracture aperture were determined from appropriate field pumping and tracer tests. The aperture spatial distribution was described by an experimental semivariogram developed from available field data. Pathogen inactivation rates were determined to be smaller than 0.15 d-1 and temperature dependent. The experimental results suggest that for the municipal wastewater injected into the Nardò aquifer the required set back distance for drinking wells should be over 3200 m.
Pathogen fate and transport in a fractured aquifer at Salento, Italy
Costantino Masciopinto;
2006
Abstract
The fate and transport of pathogens introduced by artificial groundwater recharge at the Nardò fractured aquifer in Salento, Italy is investigated. Wastewater effluents from a municipal treatment plant with known pathogen concentrations were injected into a sinkhole and the migration of pathogens in the fractured aquifer was monitored at three sampling wells. The fate of pathogens was quantified by a mathematical model describing colloid transport in a set of three-dimensional, parallel fractures with spatially variable aperture. The number of parallel fractures and their average fracture aperture were determined from appropriate field pumping and tracer tests. The aperture spatial distribution was described by an experimental semivariogram developed from available field data. Pathogen inactivation rates were determined to be smaller than 0.15 d-1 and temperature dependent. The experimental results suggest that for the municipal wastewater injected into the Nardò aquifer the required set back distance for drinking wells should be over 3200 m.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
