Improving Saline–Sodic Coalbed Natural Gas Water Quality Using Natural Zeolites
- Girisha K. Ganjegunte *a,
- George F. Vanceb,
- Robert W. Gregoryc,
- Michael A. Urynowiczd and
- Ronald C. Surdamc
- a 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
b Dep. of Renewable Resources, 1000 E. University Ave., Univ. of Wyoming, Laramie, WY 82071
c Wyoming State Geol. Survey, P.O. Box 1347, Laramie, WY 82073
d Dep. of Civil & Architectural Engineering, 1000 E. University Ave., Univ. of Wyoming, Laramie, WY 82071. Assigned to Associate Editor Dan Kaplan
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. Clinoptilolite 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 Ca2+-rich natural clinoptilolites to remove Na+ from saline–sodic CBNG waters. Batch adsorption experiments indicated that Na+ adsorption capacity of clinoptilolite ranged from 4.3 (4 × 6 mesh) to 7.98 g kg−1 (14 × 40 mesh). Among the different adsorption isotherms investigated, the Freundlich Model fitted the data best for smaller-sized (6 × 8, 6 × 14, and 14 × 40 mesh) zeolites. Passing the CBNG water through Ca2+-rich zeolite columns reduced the salt content (electrical conductivity [EC]) by 72% with a concurrent reduction in sodium adsorption ratio (SAR) from 34 (typical level in northwestern PRB) to 10 mmol1/2 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.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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