Functional Polymer Membranes for Heavy Metal Removal.
Kronenberg, Jacob B.
- The ability of COOH-functional polymer membranes previously described by Sadeghi et al. to remove metals from water was investigated. Through static adsorption tests, it was found that these membranes have functional layers with capacities comparable to other previously described adsorptive materials, but lower. Pressure-driven filtration tests were performed, which showed breakthrough curves with... read moresome residual rejection. The capacities calculated with the breakthrough curves reasonably matched those found by static adsorption and the steady-state rejections shown matched those of previously reported charge-based rejection modes. The ability of acid to regenerate these membranes was also investigated. It was found that the membranes were stable at pH 3 and that soaking in acid was sufficient to remove the metal ions bound to the membranes, allowing the membranes to be reused. Some properties of SH-functional membranes were also investigated. First, they were prepared using EDC/NHS coupling to attach SH-terminal groups to the free carboxylic acid groups on the membrane pore surface. Then, the ability of these new membranes to remove metals was investigated in static adsorption. It was found that although the SH-functional membranes did not adsorb as much metal as the COOH-functional ones, they showed a selectivity against calcium, which is useful for applications involving removal of heavy metal contaminants from hard water. Both types of membrane exhibited show promise for the ability to remove potentially hazardous heavy metal ions from water.read less