title: Co-occurrence of arsenic and fluoride in groundwater of semi-arid regions in Latin America: genesis, mobility and remediation.
abstract: Several million people around the world are currently exposed to excessive amounts of arsenic (As) and fluoride (F) in their drinking water. Although the individual toxic effects of As and F have been analyzed, there are few studies addressing their co-occurrences and water treatment options. Several studies conducted in arid and semi-arid regions of Latin America show that the co-occurrences of As and F in drinking water are linked to the volcaniclastic particles in the loess or alluvium, alkaline pH, and limited recharge. The As and F contamination results from water-rock interactions and may be accelerated by geothermal and mining activities, as well as by aquifer over-exploitation. These types of contamination are particularly pronounced in arid and semi-arid regions, where high As concentrations often show a direct relationship with high F concentrations. Enrichment of F is generally related to fluorite dissolution and it is also associated with high Cl, Br, and V concentrations. The methods of As and F removal, such as chemical precipitation followed by filtration and reverse osmosis, are currently being used at different scales and scenarios in Latin America. Although such technologies are available in Latin America, it is still urgent to develop technologies and methods capable of monitoring and removing both of these contaminants simultaneously from drinking water, with a particular focus towards small-scale rural operations.
authors.affiliation: Centro de Investigación en Materiales Avanzados (CIMAV), Ave. Miguel de Cervantes 120, Complejo Industrial Chihuahua, C.P. 31109, Chihuahua, Chih., Mexico. Electronic address: teresa.alarcon@cimav.edu.mx.
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Alarcón-Herrera
authors.forename: Jochen
authors.initials: J
authors.lastname: Bundschuh
authors.forename: Bibhash
authors.initials: B
authors.lastname: Nath
authors.forename: Hugo B
authors.initials: HB
authors.lastname: Nicolli
authors.forename: Melida
authors.initials: M
authors.lastname: Gutierrez
authors.forename: Victor M
authors.initials: VM
authors.lastname: Reyes-Gomez
authors.forename: Daniel
authors.initials: D
authors.lastname: Nuñez
authors.forename: Ignacio R
authors.initials: IR
authors.lastname: Martín-Dominguez
authors.forename: Ondra
authors.initials: O
authors.lastname: Sracek
mesh_terms: D001118:Argentina; D001151:Arsenic / Q000032:analysis*; D002677:Chile; D003889:Desert Climate; D004784:Environmental Monitoring / Q000379:methods*; D005374:Filtration; D005459:Fluorides / Q000032:analysis*; D005843:Geography; D005844:Geology; D060587:Groundwater / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007843:Latin America; D008800:Mexico; D008906:Mining; D009995:Osmosis; D010100:Oxygen / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
chemical_list: D014874:Water Pollutants, Chemical; D001151:Arsenic; D005459:Fluorides; D010100:Oxygen