Hybrid ozone-ceramic membrane process: increasing hydroxyl radical yield and OMP reduction while reducing membrane fouling

Catalan Institute for Water Research (ICRA), Girona, Spain

1. University of Girona, Spain
2. Faculty of Mechanical Engineering and Naval Architecture (FSB) , Zagreb, Croatia

Ozonation is a standard process applied for reducing OMP concentrations in secondary effluent. As many key OMPs react slowly with ozone, an increased degree of conversion of ozone to hydroxyl radicals is desirable, which would allow reducing the necessary transferred ozone dose to achieve the process aim. Two essential types of catalysts exist in heterogeneous catalytic ozonation, metal oxides and activated carbon. Ceramic membranes offer durability and high integrity, both features that are desirable in mitigating water quality risks in water reuse including microbiological ones. Recently, several studies reported on the positive impact of pre-ozonation on membrane fouling, but essentially, their metal oxide surface can act also as catalyst to decompose residual ozone, generating thereby hydroxyl radicals inside the membrane that could reduce OMPs. Optionally, suspended powered activated carbon or membrane surface modification can be used as further means to increase the hydroxyl yield. The synergistic integration of ozonation and ceramic membrane filtration thereby provides an interesting package providing abatement of chemical and microbiological contaminants alike. There are a number of unknown fundamental aspects related to this process ranging from materials science to chemical engineering that will be studied. Also, other water quality aspects will be studied, such as the influence of water matrix compounds and the reduced formation of undesired ozonation byproducts such as NDMA or bromate

Faculty of Mechanical Engineering and Naval Architecture (FSB) , Zagreb, Croatia – 12 months