Assessing the impact of micropollutants mitigation measures using vertical flow constructed wetlands for municipal wastewater catchments in the greater region: a reference case for rural areas

in Water Science and Technology (2022)

The present research aims at giving an approach to the issue of surface water contamination due to micropollutants in rural areas. The catchment of the Sûre river was selected as a reference case for the ... [more ▼]

The present research aims at giving an approach to the issue of surface water contamination due to micropollutants in rural areas. The catchment of the Sûre river was selected as a reference case for the Greater Region, characterized mainly by settlements with low population density, small water bodies and small- to medium-sized wastewater treatment plants (WWTPs). For these WWTPs, conventional technical solutions for micropollutants elimination are not suitable; therefore, an adapted mitigation strategy is needed to prevent the impact of micropollutants, especially during the dry season. As a suitable alternative to more intensive technologies, Constructed Wetlands (CW) in Vertical Flow (VF) configuration have been successfully tested over one-year period and the elimination rate of 27 micropollutants was quantified. Emission reduction by VF was then considered in a static mass balance model that calculates the longitudinal concentrations profile for the entire river catchment. The EmiSûre approach which focuses on river quality (concentrations of pollutants) instead of emitted loads, effectively allowed to simulate adopted measures a priori and resulted efficient to support decision-makers with WWTPs upgrade scenarios. [less ▲]

Removal of 27 micropollutants by selected wetland macrophytes in hydroponic conditions

in Chemosphere (2021)

Mesophilic and Thermophilic Anaerobic Digestion of Model Kitchen Waste with Variation of Fat Content

in Chemie Ingenieur Technik (2020), (2020),

Mesophilic and Thermophilic Anaerobic Digestion of Model Kitchen Waste with Variation of Fat Content

in Mesophilic and Thermophilic Anaerobic Digestion of Model Kitchen Waste with Variation of Fat Content (2018, October)

Synthetic kitchen waste, produced on basis of a real kitchen waste, and two of its variations are studied. Previous study showed that the fermentation of kitchen waste was similar to the degradation of ... [more ▼]

Synthetic kitchen waste, produced on basis of a real kitchen waste, and two of its variations are studied. Previous study showed that the fermentation of kitchen waste was similar to the degradation of synthetic kitchen waste, further called model kitchen waste (MKW) with the same amounts of carbohydrates, fats and proteins. In this study the anaerobic degradation of this MKW (named MKW1; 23 % rapeseed oil) was investigated under mesophilic and thermophilic conditions at 2 different loadings. Additional experiments were performed with lower (MKW2; 14.7 %) and higher (MKW3; 27.2 %) rapeseed oil content at the expense of starch. An organic loading of 5 gVS/l leads to a fast and undisturbed degradation under mesophilic conditions. The volatile fatty acids (mainly acetic acid) appeared only during the first 3 days. Finally the amount of biogas been produced is weakly correlated with the oil content. Under thermophilic conditions the biogas production was retarded and the concentrations of the volatile fatty acids were generally higher whereas acetic acid was present for a period of 10 days. The final biogas amount was higher than compared to mesophilc conditions. At a higher loading of 25 gVS/l a strong retardation of biogas production was observed which correlates with very high concentrations of volatile fatty acids over the whole runtime period of 50 days. [less ▲]

Vergleich der anaeroben Vergärung von realem und synthetischem Küchenabfall in Batchversuchen unterschiedlicher Beladung

in Chemie Ingenieur Technik (2018), 90(9), 1160

In the following article comparison between real kitchen waste and a synthetic kitchen waste is made. In total four experiments are discussed, all of them were conducted in batch mode at two different ... [more ▼]

In the following article comparison between real kitchen waste and a synthetic kitchen waste is made. In total four experiments are discussed, all of them were conducted in batch mode at two different loadings: 25 and 5 goDM/l and two different temperatures: mesophilic and thermophilic. [less ▲]

Two-Stage Process - a More Flexible Power Production of Biogas

in Revue Technique Luxembourgeoise (2018), 3

2-stage process for a higher flexibility of biogas-plants

Scientific Conference (2016, September 21)

The increasing part of renewable energy in the electricity production mix with its known fluctuations of wind and photovoltaic plants is leading to an enlarged discrepancy of production and consumption ... [more ▼]

The increasing part of renewable energy in the electricity production mix with its known fluctuations of wind and photovoltaic plants is leading to an enlarged discrepancy of production and consumption. Up to now the electricity production of biogas plants is more or less constant but could be used in future more to balance the energy production by using higher biogas storage capacity. An interesting alternative could be a 2 stage process. The 1st stage is operated at higher loadings and low pH where mainly substrate hydrolysis takes place and relatively small quantities of H2/CO2 gas are produced. The effluent shows high concentrations (total > 10 g FA/l) of mainly butyric and caproic acid which could easily and stable be temporarily stored in liquid-tanks. The transformation of the acidic intermediates from hydrolysis to biogas (and finally electricity) in the 2nd stage is faster compared to the traditional fermentation. The storage capacity for the acidic intermediates is more than 10 times smaller compared to the temporary storage of biogas. [less ▲]

Digestion of grass silage in a semi-continuously fed reactor at increasing loading rates - Process stability and kinetics evaluatio

in Venice 2014 5th International Symposium on Energy from Biomass and Waste Proceedings (2014, December 01)

Grass is a popular substrate in agricultural biogas plants in Central and Northern Europe. There is currently limited information about the impact of the organic loading rates (OLR) on methane yields ... [more ▼]

Grass is a popular substrate in agricultural biogas plants in Central and Northern Europe. There is currently limited information about the impact of the organic loading rates (OLR) on methane yields, process stability and kinetics for continuous systems digesting grass silage. Anaerobic mono-digestion of grass silage was evaluated in semi-continuously fed laboratory continuously stirred tank reactors (CSTRs) at increasing loading rates between 1.9 and 4.7gVS/l/d. Results show that digestion of grass silage in one-stage CSTR is feasible and do not present any loading-induced inhibition for the tested OLR range. While the volumetric methane production experienced an increase of 61%, the methane yield only decreased by 13% for the highest OLR. On the other hand, the estimated first-order hydrolysis constant decreased by 24% when increasing the loading from 1.9 to 4.7gVS/l/d, which related with an accumulation of the organic material in the reactor. It was also found that the composition of the grass silage affected the digester performance significantly. [less ▲]