Kinetic study and scaleup of the oxidation of nanofiltration retentates by ozone

This paper reports on the upscaling of an ozone reactor for the oxidation of natural organic matter. Natural organic matter is responsible for fouling of nanofiltration membranes used for drinking water production. The proposed concept is to feed the retentate stream of a nanofiltration module (400 m^3/h) to an ozone reactor (bubble column) and, subsequently, recycle it to a second nanofiltration module. The ozone oxidation of the retentate stream in the bubble column is analyzed in terms of the two-film theory with mass transfer and chemical reaction. The kinetic regime of the ozonation process, i.e., the chemical reaction rate relative to the mass transfer rate, is determined using data from lab-scale experiments. This information is used for the calculation of the reactor volume and the required ozone dose on an industrial scale. An economic assessment of the integrated nanofiltration – ozone oxidation process is given as well.status: publishe