Functionalized and Responsive Membranes for Toxic Metal Removal from Water

Selenium is a trace element that is found in the waste from the production of many electronic devices as well as coal fired power plants, mining operations and agricultural drainage. It poses an environmental danger as it is considered toxic at levels of only 50ppb. In order to prevent the poisoning of ground water, it has been found that by using a treatment of iron nanoparticles, selenium can be reduced from its toxic forms as well as captured. However, treatment with suspended iron nanoparticles leads to large losses of iron. The synthesis of iron nanoparticles within a polymer hydrogel matrix (polyacrylic acid) offers the ability to capture toxic selenium without the significant loss of iron. In addition, supporting this hydrogel in a microfiltration membrane (polyvinylidene fluoride) provides a reliable platform with numerous applications in toxic metal removal. The functionalized microfiltration membranes exhibit responsive flux behavior with change in pH and polymer loading. By offering prevention of iron nanoparticle aggregation, convective flow operation, low iron loss, and possibilities of regeneration, functionalized membranes provide a viable option for toxic metal removal from water.