Removal of Arsenic From Contaminated Water Using Micellar-Enhanced-Ultrafiltration

摘要

One of the problems in drinking water that raises concern over the world is that millions of people still have to use arsenic contaminated water. Medical research indicates that exposure to arsenic in drinking water causes urinary bladder, lung and skin cancers, gastrointestinal disorders, muscular weakness, loss of appetite, nerve tissue injuries and blackfoot disease. The U.S. Environmental Protection Agency had finalised the maximum contaminant level (MCL) for arsenic at 0.010 mg/L. In this work, the authors have investigated the performance of Micellar Enhanced Ultrafiltration for removal of arsenic species from water. Experiments have been carried out using simulated feed solution of arsenate of about 100 ppb concentration prepared by dissolving sodium arsenate in de-ionised water. Cationic surfactant, cetylpyri-dinium chloride has been used here due to its low critical micelle concentration (0.90 mM). In this work, ultrafiltration of the solution was carried out in a tangential flow module fitted with 5 kD polyethersulphone membrane so as to recover arsenic free water as permeate. Effects of surfactant concentration (0-14 mM), solution pH (5-9), co-occurring salt and effect of trans-membrane pressure on arsenic rejection and permeate flux have been thoroughly investigated. A 97.83% reduction of arsenic was recorded at pH 8 with 8 mM CPC concentration at a TMP = 3 bar.