关键词: coal-bed methane co-produced water, high salt, pretreatment process, mass balance, reverse osmosis

Abstract: This study presents the first demonstration project in China for treatment of coal-bed methane (CBM) co-produced water and recycling. The work aims to provide a research and innovation base for solving the pollution problem of CBM extraction water. The reverse osmosis (RO) unit is applied to the treatment of CBM co-produced water. The results indicate that system operation is stable, the removal efficiency of the total dissolved solids (TDS) is as high as 97.98%, and Fe, Mn, and F? are almost completely removed. There is no suspended solids (SS) detected in the treated water. Furthermore, a model for the RO membrane separation process is developed to describe the quantitative relationship between key physical quantities—membrane length, flow velocity, salt concentration, driving pressure and water recovery rate, and the water recovery restriction equation based on mass balance is de-veloped. This model provides a theoretical support for the RO system design and optimization. The TDS in the CBM co-produced water are removed to meet the “drinking water standards” and “groundwater quality standards” of China and can be used as drinking water, irrigation water, and livestock watering. In addition, the cost for treat-ment of CBM co-produced water is assessed, and the RO technology is an efficient and cost-effective treatment method to remove pollutants.

Key words: coal-bed methane co-produced water, high salt, pretreatment process, mass balance, reverse osmosis