title: Improving saline-sodic coalbed natural gas water quality using natural zeolites.
abstract: Management of saline-sodic water from the coalbed natural gas (CBNG) industry in the Powder River Basin (PRB) of Wyoming and Montana is a major environmental challenge. Clinoptilolie zeolites mined in Nevada, California, and New Mexico were evaluated for their potential to remove sodium (Na+) from CBNG waters. Based on the exchangeable cation composition, naturally occurring calcium (Ca2+)-rich zeolites from New Mexico were selected for further evaluation. Batch adsorption experiments were conducted to evaluate the potential of the Ca(2+)-rich natural clinoptilolites to remove Na+ from saline-sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity ofclinoptilolite ranged from 4.3 (4 x 6 mesh) to 7.98 g kg(-1) (14 x 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller-sized (6 x 8, 6 x 14, and 14 x 40 mesh) zeolites. Passing the CBNG water through Ca(2+)-rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption 10 mmol 1/2 L(-1/2). Zeolite technology appears to be an effective water treatment alternative to industrial membrane treatment for removing Na+ from poor-quality CBNG waters.
authors.affiliation: Dep. of Soil and Crop Sci., Texas Agrilife Res. and Extension Center, Texas A&M Univ. System, 1380 A&M Circle, El Paso, TX 79927, USA. gkganjegunte@ag.tamu.edu
authors.forename: Girisha K
authors.initials: GK
authors.lastname: Ganjegunte
authors.forename: George F
authors.initials: GF
authors.lastname: Vance
authors.forename: Robert W
authors.initials: RW
authors.lastname: Gregory
authors.forename: Michael A
authors.initials: MA
authors.lastname: Urynowicz
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Surdam
mesh_terms: D000327:Adsorption; D003031:Coal; D017753:Ecosystem; D019652:Extraction and Processing Industry; D005579:Fossil Fuels; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste; D007700:Kinetics; D012965:Sodium Chloride / Q000737:chemistry*; D012987:Soil / Q000737:chemistry*; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014876:Water Pollution / Q000517:prevention & control; D017641:Zeolites / Q000737:chemistry*
chemical_list: D003031:Coal; D005579:Fossil Fuels; D007220:Industrial Waste; D012987:Soil; D014874:Water Pollutants, Chemical; D014867:Water; D017641:Zeolites; D012965:Sodium Chloride