title: Lab-testing, predicting, and modeling multi-stage activated carbon adsorption of organic micro-pollutants from treated wastewater.
abstract: Multi-stage reuse of powdered activated carbon (PAC) is often applied in practice for a more efficient exploitation of the PAC capacity to remove organic micro-pollutants (OMP). However, the adsorption mechanisms in multi-stage PAC reuse are rarely investigated, as large-scale experiments do not allow for systematic tests. In this study, a laboratory method for the separation of PAC/water suspensions and the subsequent reuse of the PAC and the water was developed. The method was tested on wastewater treatment plant (WWTP) effluent in a setup with up to 7 PAC reuse stages. The tests show that the overall OMP removal from WWTP effluent can be increased when reusing PAC. The reason is that a repeated adsorption in multi-stage PAC reuse results in similar equilibrium concentrations as a single-stage adsorption. Thus, a single relationship between solid and liquid phase OMP concentrations appears valid throughout all stages. This also means that the adsorption efficiency of multi-stage PAC reuse setups can be estimated from the data of a single-stage setup. Furthermore, the overall OMP removals in multi-stage setups coincide with the overall UV254 removals, and for each respective OMP one relationship to UV254 removal is valid throughout all stages. The results were modeled by a simple modification of the equivalent background compound model (EBCM) which was also used to simulate the additional OMP removals in multi-stage setups with up to 50 reuse stages.
authors.affiliation: Technische Universität Berlin, Chair of Water Quality Control, KF4, Str. des 17. Juni 135, 10623 Berlin, Germany. Electronic address: frederik.zietzschmann@tu-berlin.de.
authors.forename: F
authors.initials: F
authors.lastname: Zietzschmann
authors.affiliation: Technische Universität Berlin, Chair of Water Quality Control, KF4, Str. des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Altmann
authors.affiliation: Technische Universität Berlin, Chair of Water Quality Control, KF4, Str. des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Hannemann
authors.affiliation: Technische Universität Berlin, Chair of Water Quality Control, KF4, Str. des 17. Juni 135, 10623 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Jekel
mesh_terms: D002606:Charcoal / Q000737:chemistry*; D008962:Models, Theoretical; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D002606:Charcoal; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Adsorption; Effluent organic matter; Organic micro-pollutant; Powdered activated carbon; Reuse; Wastewater