Determination of Distributions of Cd, Cu, and Pb Concentrations in Sediments of a Mexican Reservoir to Infer Their Environmental Risk

Abstract

The José Antonio Alzate Dam in the State of Mexico, Mexico, receives wastewaters from domestic, industrial, and agricultural activities through the Lerma River. Chemical and physicochemical characteristics of the water were determined. Sediment has been studied in order to define the importance of its influence on the reservoir's state as a whole. The quantification of the metals, Cd, Cu, and Pb in total forms and the geochemical distribution and the chemical mobility of these metals in sediment have been established using a chemical sequential extraction scheme. The three metals showed a common characteristic, being more abundant in fraction F6 (residual), but the other fractions of the geochemical distribution were variable depending on the metal. First, the contamination level was evaluated with the results of the total metals, using the criteria of EPA, Thomas and Murdoch, and the Ontario Ministry of Environment for sediment in water bodies. Subsequently, the risk was assessed using the same criteria but considering the results of sequential extractions, where the geochemical distribution of each metal allowed a better understanding of metal portions with more influence on the risk, in which Cu and Pb presented low risk, but not Cd.

Geographic distribution of cadmium and its interaction with the microbial community in the Longjiang River: risk evaluation after a shocking pollution accident

“…All fractions (except the residual fraction) can become available to biota under changing environmental conditions 8 . Cd also exists in different fractions in different environments, e.g., a significant proportion of the Cd was bound to the exchangeable and carbonate fractions in a slag disposal area 9 , the acid-soluble fraction (carbonates) and Fe oxide bound in a former mining area 10 , the carbonate (Na2EDTA) fraction in sewage sludge-amended soils 11 , the redox-sensitive fractions in wet and anoxic sediment 12 , and the residual fraction in agricultural soils 13 and sediments of a Mexican reservoir 14 . The stability of Cd in different environments differed with its existence form.…”

Evaluación De La Toxicidad De Los Sedimentos Del Curso Alto Del Río Lerma, México

“…Esto ya ha sido observado en estudios anteriores, en los que se concluyó que los sedimentos de esta presa actúan como un área de deposición de contaminantes y nutrientes contenidos en la columna de agua. Así, este embalse actúa como una laguna de estabilización en la que se están llevando a cabo procesos de sedimentación de contaminantes (Ávila et al 1999, Ávila 2001, Carreño 2008, Barceló et al 2012.…”

Kinetics and microbial structure of nitrogen cycle bacteria contained in the rhizosphere of natural wetland polluted with chromium

“…Water receiving bodies polluted with nitrogen compounds combined with metals indicate an ecological risk (Barceló-Quintal et al, 2012). Nitrification, denitrification, and ANAMMOX are the three biological processes involved on nitrogen cycle for the biotransformation of ammonium into N 2 .…”