Toolbox to evaluate treatment technologies for PRB CBM water

oalbed methane (CBM) co-produced water in the Powder River Basin (PRB) can contain, among other constituents, sodium ranging from 110-800 mg/L, total dissolved solids ranging from 270-2,010 mg/L, and sodium adsorption ratios ranging from 5.7-33. Due to excess sodium concentrations, untreated CBM waters may negatively affect aquatic ecosystems, damage soil characteristics, or contaminate aquifers. These issues can make it necessary to treat these waters before discharge or use. The scope of this work has been to develop the Coalbed Methane Demineralization Treatment Cost (CBM-DTC) Toolbox that provides initial demineralization technology selection for removing sodium and other constituents from PRB CBM waters based on influent water properties and effluent requirements. The toolbox has been constructed by developing performance and cost functions for selected demineralization technologies (ion exchange, reverse osmosis, electrodialysis reversal, and high efficiency electro-pressure membranes). Sensitivity analyses were performed using the toolbox to determine which parameters have the largest impact on treatment cost. The amount of sodium removed was found to be the most important parameter followed by influent flow rate, facility life and brine disposal cost. Further analyses have shown treatment costs to range from...