Concentration of organic contaminants by ultrafiltration

The results of concentration experiments on model dye solutions containing anionic surfactant and mineral salts were reported. The objective of the study involved recovery of valuable substances and water reuse. The membrane efficiency as well as dye and surfactant rejections during concentration tests were evaluated. The Mollsep Fiber (Nadir) modules with membranes made of polyethersulfone (10 and 30 kDa) were used in the experiments. The anionic surface active agent (sodium dodecyl sulphate) and sodium chloride (NaCl) were added to the dye (Direct Black) solutions. The concentration experiments were conducted at 0.1 MPa. The effect of concentration factor on the volume flux of dye solutions, dye and surfactant rejection was studied. It was found that membrane permeability and dye separation factor was kept constant during concentration process for all experimental solutions. Surfactant retention was highly influenced by solution composition and subjected to great variations. Nevertheless, it was possible to receive two streams in UF process: concentrated dye solutions and water containing anionic surfactant (SDS).