Abstract
The SDS is investigated as a surfactant for heavy metal ion removal via micellar enhanced ultrafiltration (MEUF). It is important to recover and reuse surfactant from the retentate stream due to the high cost of surfactant. Repeated acidification is a new way to recover and reuse surfactant. The effects of pH, the initial surfactant concentration of simulated retentate solution, the volume of concentrated solution, and acidification times on SDS recovery and reuse were studied. At pH 1.0, the Cd2(+) was effectively separated from the surfactant micelles, and the SDS had the highest recovery rate. Additionally, the rate of the removal by reused SDS of metal ions was higher than 85% at pH 1.0. When the initial SDS concentration of the simulated retentate solution was 2.0 CMC, the efficiency of SDS recovery and reuse was better than of that at 1.0 CMC. The smaller the concentrated solution volume was, the higher the rates of separation and removal by reused SDS of metal ions were. SDS can be repeatedly used when the concentration achieves its CMC. (C) 2017 Elsevier B.V. All rights reserved.