Removal of copper sulfate from aqueous solution by air-gap membrane distillation process

The potential use of air-gap membrane distillation (AGMD) process for the removal of copper sulfate (CuSO 4 ) from aqueous solution was examined. A series of experiments were conducted to investigate the effects of both operation parameters and module parameters, including hot feed temperature( T 3 ), coolant temperature ( T 1 ), feed flow rate ( F ), feed salt concentration ( c f ), vacuum pressure ( P ), the rate of hollow fiber membranes and heat-exchange hollow fibers ( N m / N d ) and the length of the modules ( L ) on permeate water flux ( J ), gained output ratio (GOR), water productivity ( P V ), and salt rejection rate ( R ) in AGMD process. It was found that the performance of AGMD process could be enhanced, but permeate water quality was deteriorated by adding vacuum pressure. Moreover, J declined, but P V and GOR increased as L increased. With the increment of N m / N d , J decreased when operation parameters keep constant, P V and GOR showed different variation trends with different T 1 values due to the insufficient cold energy. The highest CuSO 4 rejection rate exceeded 99.95%, so AGMD process has potential for CuSO 4 separation from aqueous solution.