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 micropollutant 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 a 1-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 concentration profile for the entire river catchment. The EmiSûre approach, which focuses on river quality (concentrations of pollutants) instead of emitted loads, effectively allowed simulation of adopted measures a priori and resulted in efficient support for decision-makers with WWTP upgrade scenarios.

In this work, the primary focus is given on a mixture of 27 micropollutants (pharmaceuticals, pesticides, herbicides, fungicides and others) and its removal from aqueous solution by phytoremediation. Phytoremediation belongs to technologies, which are contributing on removal of micropollutants from wastewater in constructed wetlands. Constructed wetlands can be used as an additional step for elimination of micropollutants from municipal medium-sized wastewater treatment plants. To our knowledge, such a broad variety of micropollutants was never targeted for removal by phytoremediation before. In this work, we carry out experiments with 3 emergent macrophytes: Phragmites australis, Iris pseudacorus and Lythrum salicaria in hydroponic conditions. The selected plants are exposed to mixture of micropollutants in concentrations 1-14 mg/l for a time period of 30 days. The highest affinity for phytoremediation is detected at groups of fluorosurfactants (removal rate up to 30%), beta-blockers (removal rate up to 50%) and antibiotics (removal rate up to 90%). The leading capability for micropollutant uptake is detected at Lythrum salicaria, where 25 out of 27 compounds are removed with more than 20% efficiency. The results demonstrate well usefulness of this technology e.g. in an additional treatment step, because the mentioned groups of micropollutants are removed with comparable or even higher effectivity, than it is in case of conventional wastewater treatment plants.

Anaerobic digestion of model kitchen waste (MKW) produced on basis of real kitchen waste (KW) is studied in batch tests. The impact of fat content of three MKWs (14.7 %, 23 %, and 27.2 % rapeseed oil content) on the biogas production at mesophilic and thermophilic conditions and two loadings is examined. The loading of 5 g(VS)L(-1)leads to fast degradation under both temperature modes and the volume of biogas produced is only weakly correlated to the oil content. For the loading of 25 g(VS)L(-1)a strong retardation of biogas production, high concentration of volatile fatty acids and no correlation of oil content is observed.

Zur Bestimmung des Abbaus von Kohlenhydraten bei der anaeroben Fermentation wurde die photometrische Anthron-Methode angepasst und fur die Modellsubstrate Glucose (wasserloslich), Mais-Starke und mikrokristalline Cellulose (beide wasserunloslich) in mesophilen BatchVersuchen uberpruft. Fur die Bestimmung des Gehalts an loslichen Kohlenhydraten wurde die Probe mit einem Spritzenaufsatzfilter (Material PTFE) auf < 0,45 µm filtriert, um alle Partikel inklusive der partikularen Kohlenhydrate abzutrennen. Die erhaltene Losung reagierte dann wahrend 8 Minuten mit der Anthronlosung in einem zuvor auf 100 °C temperierten Heizblock. Eine rasche Abkuhlung im Eiswasser auf ca. 4 °C Probentemperatur (Zeitdauer funf Minuten) erwies sich als sinnvoll, um die Farbreaktion zu stoppen und insbesondere bei groserem Probenumfang mit bedingt hoherem Zeitaufwand wiederholbare Ergebnisse zu erzielen. Vor der Messung der Extinktion am Photometer wurde die Probe bei Raumtemperatur fur ca. 30 Minuten temperiert. Eine Verdunnung der Probe war notwendig, einerseits zur Reduzierung des Farbhintergrunds, andererseits um den vorgegebenen Messbereich (λ = 625 nm) von 10 bis 100 mg Glucoseaquivalent/l einzustellen. Der Gesamtkohlenhydratanteil, der sich aus der Gesamtheit der gelosten sowie auch partikularen Fraktion zusammensetzt, wurde uber eine zusatzliche, vor der Anthron-Reaktion durchgefuhrten Vorhydrolyse mit circa 50%igem Saureanteil an H2SO4 bei 100 °C und 8 Minuten Reaktionsdauer bestimmt. Dieser separate Bestimmungsschritt, nachfolgend indirekte Methode genannt, ist notwendig, um den Anteil unloslicher bzw. polymerer Kohlenhydrate einer Probe zu bestimmen. Die Berechnung erfolgt uber Differenzbildung aus dem Gesamt- zum loslichen Kohlenhydratanteil (= partikularer Kohlenhydratanteil).

To measure the degradation of carbohydrates during fermentation, the photometrical Anthron method has been adapted. The method has been verified in mesophilic batch tests with the model substrates glucose (water-soluble), corn-starch and cellulose (both insoluble in water). First, the content of soluble carbohydrates was measured. For determination of carbo-hydrates in soluble phase, the samples were filtered (syringe PTFE filter with mesh size 0.45 μm) to separate the solution from all types of particles, particulate carbohydrates included. The soluble phase reacted with the Anthron solution for 8 minutes at 100 °C. Afterwards, the coloration reaction was stopped by a quick (5 min) cooling step in ice water to ensure repeatability of the method considering a larger number of samples to be measured. Afterwards samples had been equilibrated at room temperature for at least 30 minutes. Before measurement, the sample had to be diluted to reduce on the one hand the intensity of the background and on the other hand to obtain the measuring range (λ = 625 nm) of soluble carbohydrates of 10 to 100 mg/l. The total carbohydrate content, which consists of the soluble and particulate fraction, was determined by an additional pre-hydrolysis step (50% sulfuric acid at 100 °C during 8 minutes) before the Anthron reaction was started. To measure insoluble carbohydrates, e.g. starch and cellulose, they had to pass an additional pre-hydrolysis step which is performed before filtration and the subsequent Anthron reaction. This additional step (in the following called “indirect method”) is necessary to measure the part of insoluble respectively polymeric carbohydrates of a sample. The amount of particulate carbohydrates is further calculated by the difference between total and soluble carbohydrates.

The feasibility and performance of applying a two-stage configuration for co-production of hydrogen and methane from maize silage in continuously stirred reactors was investigated under mesophilic conditions. The high organic loading used in the first-stage hydrogen producing reactor (e.g. load shock treatment) was effective at ensuring hydrogen-producing conditions, with no methanogenic activity observed for more than 60 days. A hydrogen yield of up to 53.8 NlH2/kg volatile solid (VS) was measured in the first reactor, with a hydrogen content of 33.1%. The methane yield in the second stage reactor was 133.9 NlCH4/kgVS, with a methane content of 65%. Abnormally low concentration of acetic acid and high concentrations of caproic acid were measured in the first reactor in the pH range 5–5.5, which could be explained by the presence of strains such as Clostridium kluyveri. Of the estimated total energy yield in the two-stage system, only 4% was from hydrogen production. The mixture of hydrogen and methane produced in the system (after carbon dioxide removal) is in the range recommended for use as vehicle fuel.