Abstract

GARCIA HERNANDEZ, Jaqueline et al. Artificial wetlands as a viable treatment method for agricultural drains. Rev. Mex. Cienc. Agríc [online]. 2011, vol.2, n.spe1, pp.97-111. ISSN 2007-0934.

In this paper we present evidence generated by our working group in the last fifteen years on concentrations of pollutants and nutrients from agricultural drains that discharge into wetlands and bays of Sonora. Surveys were made in 60 sites of the Mexicali Valley, 30 sites in the Yaqui Valley and 30 sites in the rocky shores of Sonora and Baja California where samples of water, sediment, and biota were collected. Results indicate levels above established limits of: fecal coliforms, nutrients, organochlorine pesticides such as DDE and endosulfan, as well as heavy metals such as mercury, lead, and selenium. We have also observed that agricultural drains discharging in lagoons dominated by aquatic vegetation (i. e., cattail) present significant lower concentrations of contaminants and nutrients than sites lacking this kind of vegetation, considering that both systems are exposed to the same contaminants. Thus, we propose the use of constructed or artificial wetlands as a feasible option for the treatment of agricultural drains in the affected areas. This methodology has proven to be effective for the removal of nutrients, BOD, and total suspended solids in other countries. In Mexico, the Mexican Institute of Water Technology (IMTA) already has successful cases using constructed wetlands for the treatment of urban sewage. Therefore, we urge to the scientific community and the government of Mexico to promote the development of this technology in agricultural drains of Sonora.

Keywords : agricultural drains; urban discharge; artificial wetlands; Sonora; water treatment; agricultural valleys.

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