title: Naturally occurring arsenic in terrestrial geothermal systems of western Anatolia, Turkey: potential role in contamination of freshwater resources.
abstract: Arsenic (As) contamination in terrestrial geothermal systems has been identified in many countries worldwide. Concentrations higher than 0.01 mg/L are detrimental to human health. We examined potential consequences for As contamination of freshwater resources based on hydrogeochemical investigations of geothermal waters in deep wells and hot springs collected from western Anatolia, Turkey. We analyzed samples for major ions and trace element concentrations. Temperature of geothermal waters in deep wells showed extreme ranges (40 and 230 °C), while, temperature of hot spring fluids was up to 90 °C. The Piper plot illustrated two dominant water types: Na-HCO3(-) type for geothermal waters in deep wells and Ca-HCO3(-) type for hot spring fluids. Arsenic concentration ranged from 0.03 to 1.5mg/L. Dominance of reduced As species, i.e., As(III), was observed in our samples. The Eh value ranged between -250 and 119 mV, which suggests diverse geochemical conditions. Some of the measured trace elements were found above the World Health Organization guidelines and Turkish national safe drinking water limits. The variation in pH (range: 6.4-9.3) and As in geothermal waters suggest mixing with groundwater. Mixing of geothermal waters is primarily responsible for contamination of freshwater resources and making them unsuitable for drinking or irrigation.
authors.affiliation: Faculty of Engineering and Surveying & National Centre of Engineering in Agriculture, University of Southern Queensland, Toowoomba, Queensland 4350, Australia; KTH-International Groundwater Arsenic Research Group, Department of Land and Water Resources Engineering, Royal Institute of Technology (KTH), Teknikringen 76, SE-10044 Stockholm, Sweden. Electronic address: jochen.bundschuh@yahoo.com.
authors.forename: Jochen
authors.initials: J
authors.lastname: Bundschuh
authors.forename: Jyoti Prakash
authors.initials: JP
authors.lastname: Maity
authors.forename: Bibhash
authors.initials: B
authors.lastname: Nath
authors.forename: Alper
authors.initials: A
authors.lastname: Baba
authors.forename: Orhan
authors.initials: O
authors.lastname: Gunduz
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Kulp
authors.forename: Jiin-Shuh
authors.initials: JS
authors.lastname: Jean
authors.forename: Sandeep
authors.initials: S
authors.lastname: Kar
authors.forename: Huai-Jen
authors.initials: HJ
authors.lastname: Yang
authors.forename: Yu-Jung
authors.initials: YJ
authors.lastname: Tseng
authors.forename: Prosun
authors.initials: P
authors.lastname: Bhattacharya
authors.forename: Chien-Yen
authors.initials: CY
authors.lastname: Chen
mesh_terms: D001151:Arsenic / Q000032:analysis* / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D005618:Fresh Water; D005843:Geography; D060587:Groundwater; D045482:Hot Springs; D006863:Hydrogen-Ion Concentration; D013696:Temperature; D014131:Trace Elements / Q000737:chemistry; D014421:Turkey; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods; D014881:Water Supply
chemical_list: D014131:Trace Elements; D014874:Water Pollutants, Chemical; D002244:Carbon; D001151:Arsenic
keywords: Arsenic; Environmental contamination; Geothermal wells; Hot springs; Turkey