Recent results show that cylindrospermopsin is more frequent and widespread in surface waters than previously assumed. Studies on the fate of CYN in sediments are lacking, but this is important if these resources are used for drinking-water production via sediment passage. Therefore, the aim of our study was to determine a) CYN retention in two sandy sediments as a function of flow rate, CYN concentration, the presence of DOM and the content of fines (1% and 4%, respectively) and b) the influence of sediment preconditioning and DOM composition of the water (aquatic DOM versus DOM released from lysed cells) on CYN degradation. Retention of CYN proved negligible under the investigated conditions. Degradation in virgin sediments showed the highest lag phases (20 days). Preconditioned sediments showed no lag phase. The presence of aquatic DOM yielded highest degradation rates (k1 ¼0.46 and 0.49 day 1) without a lag phase. Readily available organic carbon sources were preferentially metabolized and hence induced a lag phase. Thus, the presence and composition of DOM in the water proved important for both CYN degradation rates in preconditioned sediments and for the lag phase. Cylindrospermopsin degradation took place solely in the sediment and not in the water body.

Some tropical cyanobacteria have spread to temperate freshwaters during the last decades. To evaluate their further development in temperate lakes, we studied the temperature- and light-dependent growth of three invasive (Cylindrospermopsis raciborskii, Anabaena bergii and Aphanizomenon aphanizomenoides) and three native (Aphanizomenon gracile, Aphanizomenon flos-aquae and Anabaena macrospora) cyanobacterial species (Nostocales) from German lakes. We also included one potentially invasive (Aphanizomenon ovalisporum) Nostocales species. We conducted semi-continuous culture experiments and a microcosm experiment along a natural light gradient. Temperature data were used to design a model to simulate the development of selected species according to three temperature scenarios (past, present and future). Native species had significantly higher growth rates than invasive species and the potential invader A. ovalisporum at low temperatures (<= 10 °C), while the opposite was true at high temperatures (>= 35 °C). Maximum growth rates of A. ovalisporum, A. aphanizomenoides and C. raciborskii were clearly higher than those of A. bergii and the native species. Regarding light-dependent growth, significant differences were found between single species but not between all native and invasive species. The model simulation demonstrates a shift in dominance from the native A. gracile in the historic scenario to C. raciborskii populations in the future scenario, in which also the potential invader A. ovalisporum is able to establish populations in temperate lakes. Our findings suggest that any further temperature increase would promote the growth and development of Nostocales species in general, and that of the invasive species in particular, and would enable a more northward expansion of A. ovalisporum.

Within the study “IC-Pharma” a graphical benchmark of the occurrence of 30 priority pharmaceutical active compounds (PhACs) covering different therapeutic classes such as analgesics, antibiotics, lipid lowering drugs, beta blockers, tranquilizers, and cytostatics in the urban water cycle was conducted. The results are based on an extensive data set collected during several monitoring campaigns in Berlin and the Canton Zurich. This benchmark of the occurrence of priority pharmaceuticals allows water practitioners from other sites to compare detected concentrations of priority PhACs in STP effluents, surface water and groundwater.

Over the past decade, membrane bioreactors have been increasingly implemented to purify municipal wastewater. However, even with submerged modules which offer the lowest costs, the membrane bioreactor (MBR) technology remains in most cases more expensive than conventional activated sludge processes. In addition, the European municipal MBR market is to date a duopoly of two non-European producers, despite many initiatives to develop local MBR filtration systems. In 2005, the European Commission decided to finance four projects dedicated to further technological development of MBR process: the four projects AMEDEUS, EUROMBRA, MBR-TRAIN and PURATREAT were implemented from October 2005 up to December 2009 and joined their efforts within the coalition “MBR-Network” (www.mbr-network.eu). The present report synthesises the major outcomes of the project AMEDEUS, conducted from October 2005 up to May 2009. The AMEDEUS research project aimed at tackling both issues of accelerating the development of competitive European MBR filtration technologies, as well as increasing acceptance of the MBR process through decreased capital and operation costs. The project targets the two market segments for MBR technology in Europe: the construction of small plants (semi-central, 50 to 2,000 population equivalent or p.e., standardized and autonomous), and the medium-size plants (central, up to 100.000 p.e.) for plant upgrade.

Microcystins (MCYSTs) are a group of structurally similar toxic peptides produced by cyanobacteria (“blue-green algae”) which occur frequently in surface waters worldwide. Reliable elimination is necessary when using these waters as drinking watersources.Bankfiltrationandartificial groundwaterrecharge utilize adsorption and degradation processes in the subsurface, commonlythroughsandandgravel aquifers, for the elimination of a wide range of substances during drinking water (pre-) treatment. To obtain parameters for estimating whether MCYST breakthrough is likely in field settings, we tested MCYST elimination in laboratory experiments (batch experiments, column experiments) under a range of conditions. Adsorption coefficients (kd-values) obtained from batch studies ranged from 0.2 mL/g for filter sand to 11.6 mL/g for fine grained aquifer materials with 2% fine grains (<63 µm) and 0.8% organic matter. First order degradation rates in column studies reached 1.87 d-1 under aerobic conditions and showed high variations under anoxic conditions (<0.01-1.35 d-1). These results show that, next to sediment texture, redox conditions play an important role for MCYST elimination during sediment passage. Biodegradation was identified as the dominating process for MCYST elimination in sandy aquifer material.

Within the 3.5 year ENREM project (Enhanced Nutrient REmoval in Membranebioreactors) in Berlin-Margaretenhöhe a novel and patented process was investigated to demonstrate the feasibility of a semi-decentralised solution reaching high effluent requirements set by the water authority of Berlin. This novel process could be a solution for suburban areas of Berlin which are not connected to central sewer system. The biological process combines enhanced biological phosphorus removal (EBPR) with post denitrification in MBR technology without dosing of any carbon sources. The process configuration of this demonstration plant enables advanced wastewater nutrients removal (C, P and N) and could be a promising option for wastewater treatment wherever high effluent qualities are required. A second prototype MBR system was operated in parallel, applying a different biological process, e.g. without biological phosphorus removal, enabling a comparison of these different technological approaches. The demonstration plant showed high elimination rates for COD (>95%), phosphorus (>99%) and nitrogen (up to 98%) when operated within the appropriate range of design conditions. The operational experience within the first years showed that there is a possibility for process stabilisation by changing the ratio of the process steps. For this reason the volume of the anoxic zone was enlarged by reducing the aerobic volume in Feb 2008. The positive effects could be seen on the basis of the effluent concentrations after a short period of adaptation. The membrane filtration performance was very reliable with a new cleaning strategy: Two membranes were operated alternating with an operational flux of 15 – 20 L/m²/h and a maintenance cleaning with low chemical concentration. Different cleaning agents were used in order to evaluate the cleaning efficiencies. An economical evaluation of the demonstration plant was performed in comparison to the existing wastewater treatment costs of app. 7 €/m3 by trucking away and the prototype MBR plant. Operated on the same site, the two MBR systems were used to calculate the actual costs, in relation to the effluent quality, and to perform a scale-up up to 5000 pe considering four different effluent quality classes. The results showed that the ENREM process applied in the demonstration plant is economically an alternative for plant sizes of 5000 pe and larger. For plant sizes smaller than 5000 pe, the prototype MBR system equipped with precipitation and a downstream adsorption filter for enhanced phosphorus removal proofed to be the more viable solution.