Development of nanocomposite membranes with photocatalytic surfaces

In 2030, 47% of the world population will be living in areas of high water stress (UN World Water Development Report 3, 2009). The global water shortage results in an emerging need for novel, more efficient and cost saving water purification methods. Membrane technology with its very low use of chemical substances and secure retention of contaminants represents a promising water cleaning method. The approach presented focuses on the application of nanocoating procedures to membrane processes which aims at reducing the fouling potential of membranes and destroying water contaminants. Photocatalytic titanium dioxide nanoparticles are applied. Novel suitable microsieves including a homogeneous pore size distribution and high robustness were developed from metallic material. An appropriate multilayer coating system was developed and applied on a new nanocomposite filter resulting in high photocatalytic activities with maximum photon efficiencies of 0.0733. The coating layer do not have a negative influence on the permeate flux. The effectiveness of the nanocomposite filter was proven in a 12 days biofouling experiment with activated sludge suspensions.