Impacts on effluent contaminants from mine sites: risk assessment, fate, and distribution of pollution at basin scale

Abstract

The environmental implications of mining activities are of worldwide concern. An environmental evaluation at the basin level was conducted because of widespread mining in Cajamarca in Northern Peru. A sediment monitoring program was developed at the Jequetepeque basin, located in Cajamarca. A total of 16 sites were monitored at three different times between June 2009 and July 2010, and a total of 42 samples were collected. All samples were analyzed by microwave digestion and by a sequential extraction scheme following the three-stage European Community Bureau of Reference (three-stage BCR) protocol. Trace element mobilization from the sediments to the water column was assessed by the risk assessment code (RAC). Spatial and temporal distribution of trace elements was evaluated by principal component analysis and hierarchical cluster analysis. Cd, Zn, As, and Pb showed the highest concentrations independent of season. Notably, Cu concentration and mobility increased during the wet season for all samples. Additionally, Hg concentration and mobility increased during the wet season near the mine sites. According to the enrichment factor, the highest enrichments of Cd, Zn, Pb, and As were related to mine runoff. The effect of trace elements near the mine sites at the Jequetepeque basin was considered a significant threat to the environment due to Cd, Zn, Pb, and As, and the concentrations of Cu and Hg were also considered a concern. This work establishes a baseline for the environmental quality status of the Jequetepeque basin that may support water quality management in Peru.

Experimental Study of Mobility and Kinetic Characterization of Trace Elements in Contaminated Sediments from a River Basin in Northern Peru

“…Compared with trace metal contents from mine sites in France, Chile, and Bolivia, Cu concentrations in all points are high (Coynel et al 2009;Higueras et al 2004;SalvarredyAranguren et al 2008, Yacoub et al 2014. Minimal variations between samples were obtained for Ni concentrations.…”

“…The sediment samples were dried at 105˚C until a constant weight and stored in polyethylene bottles (Yacoub et al 2014). Particles that were < 63 µm in size and which retained trace metals (Chen et al 2007) were considered for all the extraction procedures.…”

“…where C i f : the pollution coefficient of single metal; C i : the measured concentration of the sample (obtained by the pseudo-digestion procedure); C i n : the background concentration of sediments in the study site (obtained from a sampling point considered as a background at the Jequetepeque basin) (Yacoub et al 2014). T i r is the biological toxicity factor of different trace elements (the factors of Cd, As, Ni, Cu, Pb, and Zn were 30, 10, 5, 5, 5, and 1, respectively) (Wang et al 2011;Zhang et al 2012); E i r is the potential ecological risk factor of single metal and RI is the potential ecological risk index of all metals and metalloids present in the sample (Ye et al 2013).…”

“…It was evaluated using classical chemical monitoring methods for trace-level pollutants present in water and sediment (Yacoub et al 2012;Yacoub et al 2013;Yacoub et al 2014). From these findings, the present study seeks to deepen the knowledge about the most polluted sites in environmental terms by an accurate estimation of metal bioavailability and potential risk.…”

Territorios hidrosociales y minería en Cajamarca. Perú

“…Existen algunas limitaciones en el caso de la DESA, que en cierto momento obtuvo quejas por parte de la población local de diversos sectores campesinos, en-26 Para más detalles ver Yacoub, Blázquez, Pérez-Foguet y Miralles, 2013;Yacoub, Pérez-Foguet, Miralles y Valderrama, 2014. 27 Stratus Inc., 2003CAO, 2007;DESA, 2008;Yacoub, Blazquez, Pérez-Foguet y Miralles, 2013;Yacoub, Pérez-Foguet, Miralles y Valderrama, 2014. tes gubernamentales o personal de la universidad. Estos perciben varias irregularidades en su desenvolvimiento 28 , corroboradas por algunos de los resultados obtenidos 29 .…”