Municipal solid waste (MSW) in landfill bioreactors is subjected to mechanical, biological, and hydrological processes. To understand these processes, four large-scale bioreactor pilots were specifically designed to simulate the behavior of waste in the core of a landfill. Here, the results of two long-term tests that were performed in two compression cells are presented. Mechanical, biochemical, and hydrological parameters were analyzed throughout the experiments. The promising results of this research improve the understanding of biodegradation and its correlation with the hydromechanical behavior of municipal solid waste. In particular, the sensitivity of the biodegradation to leachate injection and the correlation between the biogas flow and vertical settlement were confirmed for wastes with high initial moisture content. The results showed that it is important to consider the potential of different monitoring techniques and the representative volume for the experimental approach. Furthermore, the operational results led to interesting conclusions, especially regarding the addition of moisture to waste, which is a key element for bioreactor landfill operation.

A pilot plant with a full scale monolithic ceramic membrane was operated at Ruhleben wastewater treatment plant (WWTP), Berlin Germany, for more than 12 months. Filtration performance according to the applied pre-treatment (dose of ozone and coagulant) were investigated. Trial runs with and without ozone, varying the operational parameters such as flux, coagulant dosage, and filtration time were conducted in order to identify the benefits of pre-ozonation. The reduction of the total fouling rate by ~70 % when applying a specific ozone dose between 1.0 and 1.4 mg mgDOC–1 highlights the potential of ozonation as pre-treatment step. Using LC-OCD measurements, the effect of ozone on the biopolymer concentration and the DOC fraction was demonstrated.

Data play an important role in water-related research. In the field of limnology, monitoring data are needed to assess the ecological status of water bodies and understand the bio-geochemical processes that affect this status. In wastewater management, measured or simulated data are the basis for planning and control of sewer networks. Given the importance of data in water-related research makes them a valuable resource, which should be handled in an adequate way. Based on experiences in data collection and data processing in water-related research this paper proposes – both from a computer scientist’s and an environmental engineer’s point of view – a set of rules for data handling: Rule 1: Protect raw data. Rule 2: Save metadata. Rule 3: Use databases. Rule 4: Separate data from processing. Rule 5: Use programming. Rule 6: Avoid redundancy. Rule 7: Be transparent. Rule 8: Use standards and naming conventions. Applying these rules (i) increases the quality of data and results, (ii) allows to prepare data for long-term usage and make data accessible to different people, (iii) makes data processing transparent and results reproducible, and (iv) saves – at least in the long run – time and effort. With this contribution the authors would like to start a discussion about best data handling practices and present a first checklist of data handling and data processing for practitioners and researchers working in the water sector.

This study exemplifies the use of Life Cycle Assessment (LCA) as a tool to quantify the environmental impacts of processes for wastewater treatment. In a case study, the sludge treatment line of a large wastewater treatment plant (WWTP) is analysed in terms of cumulative energy demand and the emission of greenhouse gases (carbon footprint). Sludge treatment consists of anaerobic digestion, dewatering, drying, and disposal of stabilized sludge in mono- or co-incineration in power plants or cement kilns. All relevant forms of energy demand (electricity, heat, chemicals, fossil fuels, transport) and greenhouse gas emissions (fossil CO2,CH4,N2O) are accounted in the assessment, including the treatment of return liquor from dewatering in the WWTP. Results show that the existing process is positive in energy balance (–162 MJ/PECOD * a) and carbon footprint (–11.6 kg CO2-eq/PECOD *a) by supplying secondary products such as electricity from biogas production or mono-incineration and substituting fossil fuels in co-incineration. However, disposal routes for stabilized sludge differ considerably in their energy and greenhouse gas profiles. In total, LCA proves to be a suitable tool to support future investment decisions with information of environmental relevance on the impact of wastewater treatment, but also urban water systems in general.