PURIFICATION OF PRODUCED WATER FROM COAL SEAM NATURAL GAS WELLS USING ION EXCHANGE AND REVERSE OSMOSIS

摘要

A method and apparatus are provided for treating produced water to lower the total dissolved solids of the water for safe discharge to the environment. The produced water is passed through a weak acid cation resin in H+ form (11) to remove cations, and then preferably through a decarbonator (13), to provide a first discharge stream (17). The cation loaded resin (11) is then regenerated using a dilute acid solution (18) that is preferably diluted with produced water. The resultant acid regenerated waste stream is discharged to a deep well (20). The acid regenerated resin is then rinsed, preferably with produced water (21), to remove residual salts and form a salt containing rinse stream (22). This salt containing rinse is passed into a reverse osmosis unit (23) to form a high salinity reject stream (24) rejected to a deep well (26), and a product discharge stream (25), which may be safely discharged (27).