32 Meier, Johannes Georg Melin, Thomas 416110 Publikationsserver der RWTH Aachen University Aachen German 187 S. : Ill., graph. Darst. Process combinations of powdered activated carbon adsorption and succeeding membrane process are currently under investigation for several different water treatment applications and a few full-scale applications of this kind of process already exist. Since the powdered activated carbon is usually not separated in front of the membrane process it is possible, that powdered activated carbon particles have a “mechanical” influence on the performance of the membrane, i.e. they influence the membrane process not by adsorption of solutes but by their properties as geometric bodies. This mechanical influence of powdered activated carbon particles on cross-flow membrane processes is investigated in the present thesis by the example of treatment of sewage plant effluent by powdered activated carbon adsorption and nanofiltration. Theoretical considerations, laboratory experiments and pilot plant operation show different phenomena for cross-flow at low and high shear rates. Below 2.000 s-1 an increasing deposition of particles on the membrane surface is observed due to a decreasing back-transport of particles into the bulk flow. The formation of a particle layer leads to a hindered back transport of solutes rejected by the membrane which in turn leads to a decrease of rejection for these solutes and a decrease of permeate flux due to a higher osmotic pressure. At shear rates above 18.000 s-1 an abrasive destruction of the membrane is observed. Lab scale experiments and a developed theoretical model suggest, that it is the fraction of smallest particles which is responsible for this phenomenon. Abrasion seems to increase exponentially with shear rate and linearly with distance from the starting point of the membrane cross-flow. Zusammenfassung in dt. und engl. Sprache ; Aachen, Techn. Hochsch., Diss., 2008 ; PUB:(DE-HGF)11, ; 2, ; Membranverfahren Nanofiltration Aktivkohle Abwasserreinigung Wasseraufbereitung Abrasiver Verschleiß Dissertation / PhD Thesis 2008 RWTH-CONV-112944 2008 https://publications.rwth-aachen.de/record/50398