Publications by authors named "P Cornel"

36 Publications

Fouling mitigation in anaerobic membrane bioreactors using fluidized resin beads.

Water Sci Technol 2017 Nov;76(9-10):2445-2454

Technische Universität Darmstadt, Institute IWAR, Franziska-Braun-Str. 7, Darmstadt 64287, Germany E-mail:

This study focuses on the use of fluidized resin beads to mitigate fouling during ultrafiltration (UF) of the effluent of an anaerobic bioreactor. Two different module configurations were tested: A fluidized bed of resin beads was generated in a tubular UF membrane, and a hollow fiber (HF) UF membrane was submerged into a fluidized bed, respectively. During filtration of anaerobically treated synthetic wastewater using the tubular module, fluidized resin beads with a diameter of 0.5-0.71 mm did not show any beneficial effect. In contrast, the presence of fluidized resin beads (diameter of 0.5-0.71 and 1.00-1.25 mm) in the HF module reduced the fouling rate significantly. Furthermore, particle diameter and the bed voidage affected the cleaning efficiency of a pre-fouled membrane in the HF module. Interestingly, short-term filtration tests (<2 h) of a dextran solution showed that fluidized resin beads are able to minimize concentration polarization of a macromolecule, even in the tubular module. Therefore, it is supposed that fouling of the anaerobically treated synthetic wastewater was mainly attributed to the deposition of colloidal and particulate matter.
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http://dx.doi.org/10.2166/wst.2017.420DOI Listing
November 2017

Separating grey- and blackwater in urban water cycles - sensible in the view of misconnections?

Water Sci Technol 2017 Sep;76(5-6):1132-1139

Technische Universität Darmstadt Franziska-Braun-Str. 7, Darmstadt 64287, Germany E-mail:

The infrastructure approach SEMIZENTRAL has been developed for fast growing cities, to meet their challenges regarding water supply as well as biowaste and wastewater treatment. The world's first full-scale SEMIZENTRAL Resource Recovery Center (RRC) has been implemented in Qingdao (PR China). Greywater (GW) and blackwater (BW) are collected and treated separately. Measurement of influent concentrations differ significantly from the design values. Thus, the operation strategy for the RRC had to be adapted. Amongst other reasons, the changed influent characteristic was caused by misconnections of GW and BW sewers. Already a misconnection rate of 6-8% requires an extension of the GW treatment process for nitrification/denitrification to fulfill effluent standards. Hence, measures should be taken to avoid or reduce misconnections. Nonetheless, in a semi-centralized scale (>10,000 inhabitants) a 100% avoidance might not be possible. Thus, consequences from misconnections should be considered during the design of source-oriented infrastructure systems.
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http://dx.doi.org/10.2166/wst.2017.293DOI Listing
September 2017

Fluidized glass beads reduce fouling in a novel anaerobic membrane bioreactor.

Water Sci Technol 2017 Aug;76(3-4):953-962

Technische Universität Darmstadt, Institute IWAR, Franziska-Braun-Str. 7, 64287 Darmstadt, Germany E-mail:

This study focuses on the use of fluidized glass beads as turbulence promoters in a laboratory-scale anaerobic membrane bioreactor treating municipal wastewater at 20 °C. The addition of fluidized glass beads into an external tubular ceramic membrane enabled the operation at low crossflow velocities of 0.053-0.073 m/s (mean fluxes between 5.5 and 9.7 L/(m·h)) with runtimes >300 h. Glass beads with a diameter of 1.5 mm were more effective than smaller ones with a diameter of 0.8-1.2 mm. Increasing the bed voidage from 74 to 80% did not show any beneficial effect. As scanning electron microscope examination showed, the fluidized glass beads damaged the used membrane by abrasion. The overall total chemical oxygen demand (COD) removal was between 77 and 83%, although mean hydraulic retention times were only between 1.3 and 2.3 h. The production of total methane was increased about 30% in comparison to the bioreactor without membrane. The increased methane production is presumably attributed to biological conversion of rejected, dissolved and particulate organic matter. The total required electrical energy was predicted to be about 0.3 kWh/m.
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http://dx.doi.org/10.2166/wst.2017.274DOI Listing
August 2017

Semicentralized greywater and blackwater treatment for fast growing cities: how uncertain influent characteristics might affect the treatment processes.

Water Sci Technol 2017 Apr;75(7-8):1722-1731

Technische Universität Darmstadt IWAR, Wastewater Technology and Water Reuse Franziska-Braun-Str. 7, Darmstadt 64287, Germany E-mail:

The SEMIZENTRAL infrastructure approach has been developed for fast growing cities, to meet their challenges regarding water supply as well as biowaste and wastewater (WW) treatment. The world's first full-scale SEMIZENTRAL Resource Recovery reference plant has been implemented in Qingdao (PR China). Greywater (GW) and blackwater (BW) are collected and treated separately. Measurement of influent concentrations revealed significant differences, compared with the design values. Values from the literature for GW and BW characteristics vary more markedly than for municipal WW; recommended design values are still lacking. Moreover, cross-connections between GW and BW can influence the influent characteristics considerably. Consequences for the design of GW and BW treatment are evaluated for boundary conditions, which require high effluent quality for both treatment modules. Model calculations illustrate the significant influence of uncertain WW characteristics on the required aeration basin volume and oxygen demand for GW and BW treatment; however, uncertainties are considerably reduced for the combination of these modules. Thus, a flexible design of the treatment plant is required. A possible concept for such a design is presented.
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http://dx.doi.org/10.2166/wst.2017.047DOI Listing
April 2017

Survival, reproduction, growth, and parasite resistance of aquatic organisms exposed on-site to wastewater treated by advanced treatment processes.

Aquat Toxicol 2017 May 2;186:171-179. Epub 2017 Mar 2.

ECT Oekotoxikologie GmbH, 65439, Flörsheim, Germany.

Advanced wastewater treatment technologies are generally known to be an effective tool for reducing micropollutant discharge into the aquatic environment. Nevertheless, some processes such as ozonation result in stable transformation products with often unknown toxicity. In the present study, whole effluents originating from nine different steps of advanced treatment combinations were compared for their aquatic toxicity. Assessed endpoints were survival, growth and reproduction of Lumbriculus variegatus, Daphnia magna and Lemna minor chronically exposed in on-site flow-through tests based on standard guidelines. The treatment combinations were activated sludge treatment followed by ozonation with subsequent filtration by granular activated carbon or biofilters and membrane bioreactor treatment of raw wastewater followed by ozonation. Additionally, the impact of treated wastewater on the immune response of invertebrates was investigated by challenging D. magna with a bacterial endoparasite. Conventionally treated wastewater reduced reproduction of L. variegatus by up to 46%, but did not affect D. magna and L. minor with regard to survival, growth, reproduction and parasite resistance. Instead, parasite susceptibility was significantly reduced in D. magna exposed to conventionally treated as well as ozonated wastewater in comparison to D. magna exposed to the medium control. None of the three test organisms provided clear evidence that wastewater ozonation leads to increased aquatic toxicity. Rather than to the presence of toxic transformation products, the affected performance of L. variegatus could be linked to elevated concentrations of ammonium and nitrite that likely resulted from treatment failures.
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http://dx.doi.org/10.1016/j.aquatox.2017.03.001DOI Listing
May 2017
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