report
6.4.4 Additional demand for research

Photocatalytic applications are promising but industrialized countries already have elaborated water treatment systems in operation that meet the current legislation. They will thus not be replaced unless photocatalytic systems prove to be cheaper or yield a significantly improved water quality. It is though not yet possible to analyse all side and end products of photocatalytic conversion which depend not only on the substances present in the water, but also on temperature, pH and other factors. It is thus necessary to develop the according analythical methods to determine side and end products.

Future objectives in the water treatment with oxidative nanomaterials are to further reduce COD (chemical oxygen demand) and to find an alternative cathode material to BDD in order to lower costs, reduce energy through the use of a low overpotential cathode, reduce N-organics and NH4 content, and optimise the efficiency by increasing the process temperature.

In the field of nanofiltration, further research is needed to avoid membrane fouling e.g. by the use of hydrorphilic low-fouling membranes or the control of the membrane charge. It will also be necessary to find materials that can be produced in larger quantities for commercial application.