Assessment of the Environmental Impacts of Coalbed Methane Development in the Powder River Basin - Use of Coalbead Methane Produced Water for Cropland Irrigation

Jeff Morris

关键词: BURNERS;    BY-PRODUCTS;    COAL;    COAL DEPOSITS;    DRAINAGE;    ELECTROLYTES;    ENVIRONMENTAL IMPACTS;    GYPSUM;    HYDRAULIC CONDUCTIVITY;    IRRIGATION;    METHANE;    NATURAL GAS;    NUTRIENTS;    PHOTOSYNTHESIS;    PLANT GROWTH;    POWDER RIVER BASIN;    SALINITY;    SOIL CHEMISTRY;    SULFUR;    WATER QUALITY;   

DOI  :  10.2172/993128
RP-ID  :  None
PID  :  OSTI ID: 993128
Others  :  TRN: US201023%%408

美国|英语

来源: SciTech Connect

【 摘 要 】

Water quality is a major concern with regard to development of coalbed methane (CBM) in the Powder River Basin, Wyoming. Large quantities of water are being produced and discharged as a by-product in the process of releasing natural gas from coal. Current practices of discharging large volumes of water into drainage channels or using it to irrigate cropland areas has the potential to elevate salinity and sodicity in soils. Elevated salinity affects the ability of plants to uptake water to facilitate biochemical processes such as photosynthesis and plant growth. Elevated sodicity in irrigation water adversely affects soil structure necessary for water infiltration, nutrient supply, and aeration. Salinity and sodicity concentrations are important in that a sodic soil can maintain its structure if the salinity level is maintained above the threshold electrolyte concentration. In this study, cropland soil and CBM water were treated with gypsum and sulfur. Changes in soil chemistry among different treatments were monitored using a split plot experiment. The CBM water used for irrigation had an EC of 1380 {micro}S cm{sup -1} and SAR of 24.3 mmol{sup 1/2} L{sup -1/2}. Baseline and post treatment soil samples were collected to a depth of 60 cm within each study plot, analyzed, and characterized for chemical parameters. Comparisons between Spring 2004 and Fall 2004 soil chemistry data after one irrigation season (using the equivalent of 1 month of irrigation water or {approx}12 inches) indicated that irrigating with Piney Creek water or a 50:50 blend of Piney Creek water and CBM water did not cause SAR values to increase. A combination of using a gypsum amendment to the soil along with a gypsum injection and sulfur burner treatment to the irrigation water resulted in the lowest SAR value in the first soil horizon among treatments irrigated solely with CBM produced water. The SAR value resulting from this combination treatment was 53% lower than using CBM water with no amendments to soil or water. Soil amendments to cores in the laboratory did not increase soil hydraulic conductivity when CBM water was applied.