Heavy metal pollution is a main issue for integrated watershed management worldwide. Before planning any remediation strategy, it is essential to quantify the input and output fluxes of metal by analyzing the environmental system in all its main components. Physically based models can simulate the behavior of a system, such as a river watershed, starting from the knowledge of the physical processes occurring therein. In this study, the abandoned mining area of the Rio San Giorgio (SW Sardinia) was modeled. Rio San Giorgio catchment is characterized by several mines, wastes and tailing dumps, abandoned after centuries of intense exploitation of Zn and Pb. Among them, the Fanghi Rossi and Campo Pisano dumps are important sources of pollution due to their high contents of contaminants (De Giudici et al., 2017). SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) hydrological model and SWAT-HM (SWAT- Heavy Metal module, Meng et al., 2018) were used to simulate the fate and the transport of the Zn and Pb in the surface waters of Rio San Giorgio. The models were calibrated against measured streamflow and observed concentrations of Zn and Pb. Future simulations were run using Regional Climate Models of the Euro-CORDEX experiment (Giorgi et al., 2009) as climate forcing, to evaluate how pollution could evolve with climate change. Moreover, the impact of the removal of two of the main wastes, namely Fanghi Rossi and Campo Pisano, was simulated. Based on future climate simulations, results showed a small increase (15%) of the mean Zn load is projected, caused by peak loads in occurrence of extreme rainfall events, while mean Pb load showed a significant decrease of around -40%. Waste management scenarios showed that the Fanghi Rossi waste remediation would result in a decrease of -40% of Zn and -34% of Pb loads, while Campo Pisano waste remediation would produce a reduction of -9% of Zn and -35% of Pb loads. The described projections add critical information to support waste management practices. This methodology could be applied in different watersheds affected by mine pollution.
Modeling the fate and the transport of heavy metals in a mine-polluted river watershed
Marras P. A.
;De Giudici G. B.;Medas D.;Dore E.
2022-01-01
Abstract
Heavy metal pollution is a main issue for integrated watershed management worldwide. Before planning any remediation strategy, it is essential to quantify the input and output fluxes of metal by analyzing the environmental system in all its main components. Physically based models can simulate the behavior of a system, such as a river watershed, starting from the knowledge of the physical processes occurring therein. In this study, the abandoned mining area of the Rio San Giorgio (SW Sardinia) was modeled. Rio San Giorgio catchment is characterized by several mines, wastes and tailing dumps, abandoned after centuries of intense exploitation of Zn and Pb. Among them, the Fanghi Rossi and Campo Pisano dumps are important sources of pollution due to their high contents of contaminants (De Giudici et al., 2017). SWAT (Soil and Water Assessment Tool, Arnold et al., 1998) hydrological model and SWAT-HM (SWAT- Heavy Metal module, Meng et al., 2018) were used to simulate the fate and the transport of the Zn and Pb in the surface waters of Rio San Giorgio. The models were calibrated against measured streamflow and observed concentrations of Zn and Pb. Future simulations were run using Regional Climate Models of the Euro-CORDEX experiment (Giorgi et al., 2009) as climate forcing, to evaluate how pollution could evolve with climate change. Moreover, the impact of the removal of two of the main wastes, namely Fanghi Rossi and Campo Pisano, was simulated. Based on future climate simulations, results showed a small increase (15%) of the mean Zn load is projected, caused by peak loads in occurrence of extreme rainfall events, while mean Pb load showed a significant decrease of around -40%. Waste management scenarios showed that the Fanghi Rossi waste remediation would result in a decrease of -40% of Zn and -34% of Pb loads, while Campo Pisano waste remediation would produce a reduction of -9% of Zn and -35% of Pb loads. The described projections add critical information to support waste management practices. This methodology could be applied in different watersheds affected by mine pollution.
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