Characterization of unconventional sand-based substrates for adsorption of micropollutants in nature-based systems

in Journal of Environmental Management (2022)

The focus of this study is the characterization of unconventional sand-based substrates used in our previous project EmiSûre, (Interreg Greater Region (German federal states Rhineland-Palatinate and ... [more ▼]

The focus of this study is the characterization of unconventional sand-based substrates used in our previous project EmiSûre, (Interreg Greater Region (German federal states Rhineland-Palatinate and Saarland, the Grand Duchy of Luxembourg, regions Wallonia and Lorraine from Belgium and France, respectively), 2017–2021). The project aimed to develop and test alternative, nature-based technologies for the elimination of micropollutants (MPs) from municipal wastewater. For the characterization, two approaches were chosen. In the first approach, adsorption kinetics with a single compound allowed a perception of the adsorption capacity of the studied substrates compared to conventional substrates (granular activated carbons). This knowledge was completed by the second approach: an implementation of the studied substrates in packed-bed columns, which treated a mixture of 27 MPs in tap water for 10 months. Additionally, all three substrates (bentonite sand, sand with 15% activated biochar and sand with 15% zeolite) were characterized for physical and chemical properties, and the microbial potential of the activated and non-activated biochar was examined. From the studies, it is clear that the sand with an admixture of activated biochar is the most efficient sorbent in terms of single compound adsorption in batch (dye) and adsorption of 27 MPs on packed-bed columns. In contrast to the two other substrates, it shows long-term stable removal efficiencies. In the packed-bed columns, 18 out of 27 compounds were removed on average with high efficiency (80–99%), which is impressive, if we consider the variety of the compounds examined (pharmaceuticals, herbicides, pesticides, etc.) and their removal in conventional treatments. Addi- tionally, adsorption models were created for the experimental data of all compounds adsorbed on the substrate with an admixture of activated biochar resulting in the best fit with the combined Langmuir-Freundlich model. These satisfying results suggest the application of the sand-based substrate with an admixture of activated biochar for further research and possibly upscale installations with the aim to offer and prove a reasonable and efficient alternative for MPs elimination from municipal wastewater. [less ▲]

Feasibility of Advanced Oxidation Processes as an upgrade for Microcontaminants removal at municipal Wastewater Treatment Plants

Scientific Conference (2022, June)

Benzotriazole, carbamazepine, clarithromycin and diclofenac have been identified as microcontaminants of concern in Luxembourgish wastewaters, thus the implementation of photo-Fenton processes at natural ... [more ▼]

Benzotriazole, carbamazepine, clarithromycin and diclofenac have been identified as microcontaminants of concern in Luxembourgish wastewaters, thus the implementation of photo-Fenton processes at natural pH has been proposed for their removal. In the present work, the effectiveness of a pilot scale photo-Fenton system (500W Medium Pressure) has been evaluated according to the reagent dosage and toxicity of the treated effluent. With this treatment, 80% degradation is achieved in 15 minutes even with 5 and 3 mg/L of iron (40 mg/L H2O2), but 5 mg/L can have a negative effect on the growth of Sorghum saccharatum in Phytotoxicity tests. In comparison UV-C/H2O2 (40W Low Pressure; 40 mg/L H2O2) process needs longer treatment time and generates degradation by-products causing a growth inhibition of Sorghum saccharatum. The combination of both lamps can lead to a better performance of the reagents allowing to reach the 80% target in less time and to reduce the dosage. [less ▲]

Bioremediation of 27 Micropollutants by Symbiotic Microorganisms of Wetland Macrophytes

in Sustainability (2022), 14(7), 3944

Background: Micropollutants in bodies of water represent many challenges. We addressedthese challenges by the application of constructed wetlands, which represent advanced treatmenttechnology for the ... [more ▼]

Background: Micropollutants in bodies of water represent many challenges. We addressedthese challenges by the application of constructed wetlands, which represent advanced treatmenttechnology for the removal of micropollutants from water. However, which mechanisms specificallycontribute to the removal efficiency often remains unclear. Methods: Here, we focus on the removalof 27 micropollutants by bioremediation. For this, macrophytesPhragmites australis,Iris pseudacorusandLythrum salicariawere taken from established wetlands, and a special experimental set-up wasdesigned. In order to better understand the impact of the rhizosphere microbiome, we determinedthe microbial composition using 16S rRNA gene sequencing and investigated the role of identifiedgenera in the micropollutant removal of micropollutants. Moreover, we studied the colonizationof macrophyte roots by arbuscular mycorrhizal fungi, which are known for their symbiotic rela-tionship with plants. This symbiosis could result in increased removal of present micropollutants.Results: We foundIris pseudacorusto be the most successful bioremediative system, as it removed22 compounds, including persistent ones, with more than 80% efficiency. The most abundant generathat contributed to the removal of micropollutants werePseudomonas, Flavobacterium, Variovorax,Methylotenera, Reyranella, AmaricoccusandHydrogenophaga.Iris pseudacorusexhibited the highest colo-nization rate (56%). Conclusions: Our experiments demonstrate the positive impact of rhizospheremicroorganisms on the removal of micropollutants. [less ▲]

Characterizing the theory of energy transition in Luxembourg— Part three— In the residential sector

in Energy Science and Engineering (2022)

Increasing consciousness to address future concerns is a challenging subject, noticed considerably by policymakers and investors. Investigation of energy use in residential buildings in terms of quantity ... [more ▼]

Increasing consciousness to address future concerns is a challenging subject, noticed considerably by policymakers and investors. Investigation of energy use in residential buildings in terms of quantity and sources of energy was the main focus of this study. Indeed, the paper was aimed to study the role of contextual factors on two points: the energy demand and the spreading of renewable technologies in the residential sector. It was theory- driven research to highlight some future concerns. The first theory was to reveal how the growth of single- family houses versus multi- family houses could affect the growth of energy consumption and the application of renewable technologies. The second theory was built to highlight that spreading energy measures to increase efficiency or introducing a new energy carrier should be embedded in the context of new construction activities or in a template of renovation projects. The third theory was to emphasize the priority of thinking about managing the changes in residential buildings because of the lasting impact of the decision about the type of building. Finally, the purpose of the ongoing transition was argued to highlight that the growth of renewable technologies has not been necessarily aligned with getting away from fossil fuels. [less ▲]

Combinated Treatment of Wastewater Using Photo-Fenton and Granular Active Carbon Enhancing the Microcontaminants Removall

in Proceedings of the 39th IAHR World Congress (Granada, 2022) (2022)

Characterizing the Theory of Energy Transition in Luxembourg, Part Two—On Energy Enthusiasts’ Viewpoints

in Sustainability (2021)

Removal of 27 micropollutants by selected wetland macrophytes in hydroponic conditions

in Chemosphere (2021)

Quantification of removal mechanisms in vertical flow constructed wetlands as nature based solutions for treatment of wastewater effluent

Poster (2021, March 18)

Eliminace mikropolutantů z odpadních vod – užití kořenových čistíren jako technologie pro čištění odtoku z čistírny odpadních vod

in „Mladá voda břehy mele 2020“ Sborník konference (2020, September 09)

Removal of micropollutants in medium-sized WWTP by vertical flow constructed wetlands (VFCWs): performance under laboratory and real conditions

in Removal of micropollutants in medium-sized WWTP by vertical flow constructed wetlands (VFCWs): performance under laboratory and real conditions (2020, February 14)

Micropollutants generated in urban agglomerates are commonly found in aquatic environments where they may present a potential danger. Constructed wetlands (CWs) are an attractive alternative for the ... [more ▼]

Micropollutants generated in urban agglomerates are commonly found in aquatic environments where they may present a potential danger. Constructed wetlands (CWs) are an attractive alternative for the removal of those compounds from the effluent of medium-sized wastewater treatment plants (WWTPs). To this end, the INTERREG Greater Region-funded project EmiSûre aims to find solutions to mitigate the emission of micropollutants from wastewater facilities. As a part of the project, this study starts with the trial of vertical flow (VF) CWs under lab-scale conditions aiming to select the best substrate. Following steps are designed to optimize the performance of VFCWs in terms of removal of micropollutans under real conditions (i.e. matrix, seasonal changes, temperature) and to derive first approaches for dimensioning. From all the examined substrates, activated biocoal showed the best results in removing macro- and micropollutants and is expected to be the most suitable substrate in long term perspectives. [less ▲]