Photocatalytic ozonation in an immersion rotary body reactor for the removal of micro-pollutants from the effluent of wastewater treatment plants

Abstract

Carrier-bound titanium dioxide catalysts were used in a photocatalytic ozonation reactor for the degradation of micro-pollutants in real wastewater. A photocatalytic immersion rotary body reactor with 36 cm disk diameter was used, which was irradiated using UV-A LEDs. The rotating disks were covered with catalysts based on stainless steel grids coated with titanium dioxide. The dosing of ozone was carried out through the liquid phase via an external enrichment and a supply system transverse to the flow direction. The influence of irradiation power and ozone dose on the degradation rate for photocatalytic ozonation was investigated. In addition, the performance of the individual processes photocatalysis and ozonation were studied. The degradation kinetics of the parent compounds were determined by LC-MS/MS. First-order kinetics were determined for photocatalysis and photocatalytic ozonation. A maximum reaction rate of the reactor was determined, which could be achieved by both photocatalysis and photocatalytic ozonation. At a dosage of 0.4 mg /mg DOC, the maximum reaction rate could be achieved using 75% of the irradiation power used for sole photocatalysis, allowing increases in the energetic efficiency of photocatalytic wastewater treatment processes. The process of photocatalytic ozonation is suitable to remove a wide spectrum of micro-pollutants from wastewater. HIGHLIGHT within the work, reaction rates for the degradation of micropollutants in real wastewater matrix are presented. due to the number of investigated pollutants as well as the practical investigation conditions, a more precise evaluation of the use of photocatalysis and photocatalytic ozonation for wastewater treatment is possible.

Behavior of matrix parameters and their correlation to micro-pollutant degradation during treatment of real wastewater by carrier-bound photocatalytic ozonation

“…It is evident that there is a limitation of the reaction rate of the reactor independent of the tested operating parameters. The same behavior was also observed for the reaction rates of the studied micro-pollutants (Mehling et al 2021). Consequently, similar SAC reductions as in (Mecha et al 2016) could be achieved.…”

“…The presented measurement data is an extension of the research results in (Mehling et al 2021). Here, the reaction behavior of the parent substances of eight micro-pollutants was investigated and described in more detail in the same experimental setup.…”

“…The catalyst material used was similar to previous works with more detailed descriptions in (Schnabel et al 2020;Schnabel et al 2021). During the coating process it was immobilized onto a V4A stainless steel mesh (316 L/1.4404) with a mesh size of 200 μm and a wire thickness of 100 μm.…”

Investigation on Energetic Efficiency of Reactor Systems for Oxidation of Micro-Pollutants by Immobilized Active Titanium Dioxide Photocatalysis

“…A more detailed description of the catalyst material used is given in previous works [23,24]. It consists of a suspension of anatase-modified titanium dioxide nanoparticles of 14 nm diameter and an anatase content of the titanium dioxide of 90%, which is coated onto a stainless-steel mesh.…”

“…Laboratory scale batch reactor • Laboratory scale flat cell reactor • Semi-technical photocatalytic immersion rotary body reactor Data regarding the individual cleaning performance are already published for the flat cell [24] and the immersion rotary body reactor [23].…”