Showing papers by "Korneel Rabaey published in 2019"
TL;DR: A new pathway is proposed that allows for mainstream ammonium recovery from wastewater based on physico-chemical adsorption through development of polymer-based adsorbents, and can bring forward an effective resource-oriented approach to upgrade the fate of ammonium in urban water management without generating hidden externalized environmental costs.
Abstract: Throughout the 20th century, the prevailing approach toward nitrogen management in municipal wastewater treatment was to remove ammonium by transforming it into dinitrogen (N2) using biological pro...
103 citations
TL;DR: In this article, the authors applied fermentative granulation to the valorization of solid-free thin stillage, through a high-rate chain elongation process for the production of MCCA without the addition of exogenous electron donating intermediates.
53 citations
TL;DR: In this paper, the authors used membrane electrolysis to generate hydroxyl groups in situ in a two-chamber electrochemical cell with a side crystallizer, omitting the need for chemical addition and not leading to substantial loss of lithium rich brine.
53 citations
TL;DR: It is shown that O2-reducing EABs can grow in unamended tap water on carbon electrodes at + 0.2 V vs. Ag/AgCl and remain substantial electroactivity for at least eight months without adding exogenous compounds.
49 citations
TL;DR: The membrane stripping reactor is preferred as it improved nitrogen recovery with less energy input and generated an E. coli- and micropollutant-free product for potential safe reuse and nitrogen removal rate and efficiency can be further optimized by increasing the NH3 vapor pressure gradient and/or membrane surface area.
42 citations
01 Jan 2019
TL;DR: The results obtained in this study together with engineering calculations show that the proposed process could represent a cost-effective approach for sodium and sulfur recovery from SCS.
37 citations
TL;DR: A dissolved air flotation unit was coupled to a HRAS system or a high-rate contact stabilization system, enabling direct organics removal at high sludge concentration and with low chemical needs.
35 citations
TL;DR: In this paper, an Acetobacterium isolate was found to significantly increase Fe(0) corrosion ((1.44 ± 0.16)-fold) compared to abiotic controls.
34 citations
TL;DR: In this article, six commercially available electrode materials (Ir Mixed Metal Oxide (MMO), Ru MMO, Pt/IrOx, Pt, PbOx and TiO2/IrTaO2 coated titanium-based electrodes) were tested to investigate the impact of the electrocatalyst on the process efficiency in terms of sulfide removal and final product of sulfides oxidation, as well as to determine the stability of the Electrocatalyst under high sulfide concentrations (50mM Na2S) and high alkalinity (pH>12).
23 citations
TL;DR: In this paper, an electrochemically assisted scrubbing and stripping of CO2 and H2S resulted in high CO2 removal efficiencies (up to 100%), without addition of chemicals.
22 citations
TL;DR: In this paper, the authors integrated a fed-batch Basfia succiniciproducens succinic acid fermentation with membrane electrolysis, which brought the broth in direct contact with an OH- and H-2 producing cathode, and enabled in situ extraction of succinate towards the low volume H+ and O-2 generating anode compartment.
TL;DR: Overall, this study demonstrates that in-situ generation of iron and alkalinity is an effective alternative method for hydrogen sulfide control in sewers.
TL;DR: Overall, this work shows that the combined fermentation, electrochemistry and homogeneous catalysis enables fine chemical production from side streams.
TL;DR: Ureolysis was identified as the only process significantly impacting the microbial community, indicating external inoculation would not be required to serve as a controlled environment to release NH3 and remove divalent cations to prevent scaling in downstream transport and processing.
15 Mar 2019
TL;DR: In this paper, anodic electroactive biofilms (EABs) are grown under continuous polarization of the underlying electrode and then switched from continuous to periodic and vice versa.
Abstract: Anodic electroactive biofilms (EABs) are commonly grown under continuous polarization of the underlying electrode. Their growth under appropriate periodic polarization was recently reported to considerably enhance their electrochemical properties (catalytic current and charge carriers concentration). This improvement was only investigated on relatively short term (ten days), and its resilience once the periodic polarizations are switched back to continuous (or vice versa) has not yet been assessed. Here, we first cultivated 16 Geobacter-dominated EABs on glassy carbon electrodes under either continuous or periodic polarization for several days. The polarization mode was then switched from continuous to periodic and vice versa. The improvement induced by the initial periodic polarization was lost over only two days of continuous polarization. Conversely, it took about ten days of periodic polarization to fully improve the electroactivity of the EABs initially grown under continuous polarization. The periodic polarization favored biofilm detachments, which were followed by a full recovery of current within three days. The performance of EABs under periodic polarization was less negatively impacted under substrate-limiting conditions, likely because of substrate replenishment during open circuit periods.
TL;DR: A novel rapid polarization curve measurement procedure with a dynamic measurement resolution that runs on a custom six-channel potentiostat with a current-driven topology to speedup characterization and facilitate low-cost, yet widely parallel measurements.
Abstract: Knowledge of the performance of microbial electrolysis cells under a wide range of operating conditions is crucial to achieve high production efficiencies. Characterizing this performance in an experiment, however, is challenging due to either the long measurement times of steady-state procedures or the transient errors of dynamic procedures. Moreover, wide parallelization of the measurements is not feasible due to the high measurement equipment cost per channel. Hence, to speedup this characterization and to facilitate low-cost, yet widely parallel measurements, this paper presents a novel rapid polarization curve measurement procedure with a dynamic measurement resolution that runs on a custom six-channel potentiostat with a current-driven topology. As case study, the procedure is used to rapidly assess the impact of altering pH values on a microbial electrolysis cell that produces H2. A $\times 2$ – $\times 12$ speedup could be obtained in comparison with the state-of-the-art, depending on the characterization resolution (16–128 levels). On top of this speedup, measurements can be parallelized up to $6\times $ on the presented, affordable—42$-per-channel—potentiostat.
01 Sep 2019
TL;DR: A novel, widely scalable channel architecture using a switch capacitor based Howland current pump and a digital potential controller is presented and an integrated, 64-channel CMOS potentiostat array is fabricated.
Abstract: Electrochemical monitoring is crucial for both industrial applications, such as microbial electrolysis and corrosion monitoring as well as consumer applications such as personal health monitoring. Yet, state-of-the-art integrated potentiostat monitoring devices have few parallel channels with limited flexibility due to their channel architecture. This work presents a novel, widely scalable channel architecture using a switch capacitor based Howland current pump and a digital potential controller. An integrated, 64-channel CMOS potentiostat array has been fabricated. Each individual channel has a dynamic current range of 120dB with 1.1pA precision with up to 100kHz bandwidth. The on-chip working electrodes are post-processed with gold to ensure (bio)electrochemical compatibility.
15 Oct 2019
TL;DR: In this article, the authors focus on electrochemical metal recovery from wastes, noting also (bio)electrochemical synthesis of high-value organic compounds on the cathode, and biological electricity production from wastewaters at the anode.
Abstract: The demand for mineral and energy resources is increasing. Resources are sourced from finite geological deposits. Therefore the development of more sustainable routes is paramount. Industrial, municipal and agricultural wastewaters are potential sources of metals and energy can be recovered from oxidising waste organic matter but conventional methods are not technically or economically feasible. Bioelectrochemical systems (BES) have the potential to overcome these problems. Integrated BES can combine wastewater treatment, energy generation and resource recovery. Organic waste generated annually by humans globally contains ca. 600–1200 TWh of energy. BES can harvest energy as electricity from wastewater but the coulombic yields and power outputs are uncompetitive with alternative systems for electricity production from waste. Alternative uses of energy recovered from wastewaters by BES include resource recovery from waste streams (e.g. metals), offering wastewater treatment while valorising a waste stream for valuable product recovery. This chapter focuses on electrochemical metal recovery from wastes, noting also (bio)electrochemical synthesis of high-value organic compounds on the cathode, and biological electricity production from wastewaters at the anode. We review how fundamental microbial processes can be harnessed for resource recovery and the environmental benefits, and consider scale-up, environmental and economic costs and benefits of BES technologies for resource recovery.