Chitosan hydrogel synthesis to remove arsenic and fluoride ions from groundwater.

Groundwater samples from eight deep drinking water wells that cover three aquifers in Chihuahua City, northern Mexico, were fully characterized. Water is naturally contaminated with arsenic, fluoride, and uranium, according to the Environmental Protection Agency (EPA) and local standards. The results from the Geochemist's Workbench (GWB) program revealed that the minerals in equilibrium with the groundwater were calcite and dolomite, while others, such as fluoride, schoepite, rutherfordite and K(UO)(AsO), were also dissolved.

Exploratory study on the presence of bisphenol A and bis(2-ethylhexyl) phthalate in the Santa Catarina River in Monterrey, N.L., Mexico.

The current problem related to the supply of drinking water for the metropolitan area of Monterrey, which comprises of five million inhabitants, and the important role played by the El Cuchillo Dam, found downstream of the Santa Catarina River basin as a surface source of drinking water for the city, renders this river an interesting site for assessment. This work evaluates the degree to which the surface water and the subsoil of the river are affected by emerging organic pollutants due to their existence, even at low concentrations, representing a toxic risk enhanced by the absence of stricter standards for regulating these substances. Based on fieldwork, three discharge points that could affect the quality of the surface water were selected: two points on the river stream, and three groundwater wells.