PVC geomembranes in pumped storage schemes
© Springer Vieweg | Springer Fachmedien Wiesbaden GmbH (5/2013)
Construction of pumped storage schemes is increasing in many European countries and around the world to implement/backup the energy production from windmills. To ensure efficient and safe operation, the storage reservoirs must be watertight and maintain watertightness over time. Traditional waterproofing solutions like concrete and bituminous concrete linings need periodical and/or accidental maintenance that may have significant impact on operation of the scheme. A viable alternative, based on well-proven systems adopted for new construction and rehabilitation of dams and reservoirs, is to use impervious flexible geomembranes, generally Polyvinylchloride (PVC) composite membranes embedding a backing geotextile for anti-puncture protection, which can be installed on fairly uneven base layers, reducing surface preparation.

Lime Treatment: New Perspectives for the use of Silty and Clayey Soils in Earthen Hydraulic Structures
© Springer Vieweg | Springer Fachmedien Wiesbaden GmbH (5/2013)
This paper describes the SOTREDI project, “Soil TREatment for Dikes”, undertaken by Lhoist Group, a lime producer, since 2005. This project was led in partnership with research centres and universities, and presents new perspectives for the use of soils in hydraulic context. The objective was to demonstrate that soil treatment with lime, besides enhancing the materials workability, confers high levels of mechanical properties and low permeability values. Lime-treated soils also offer a reduction of piping and internal erosion hazards, and significantly increase the erosion resistance against overtopping and overflowing.

Risks and Potentials Related to Shallow Urban Aquifers - A Mexican Example Urban Aquifer Management
© DIV Deutscher Industrieverlag GmbH (9/2012)
Unconfined urban aquifers as source and sink are a key element within the total urban water cycle. Unlike deeper and mostly better quality aquifers, shallow urban aquifers are (i) much more vulnerable to contamination from urban landuse, (ii) may impact urban infrastructure more directly by cellar flooding and infiltration into sewers, (iii) are easily accessible and therefore abstraction is harder to control. For the latter, they are often used - but rarely managed. In the present study, the Mexican city of San Luis Potosi (1.1 Mio inhab.) is used to demonstrate an assessment framework for shallow groundwater resources in integrated urban water management (IUWM). Assessment parameters include aquifer geometry, flow regime, water quality, existing use and potential water demand. The evaluation shows that the shallow aquifer is fit for different type of use concepts. The results have been communicated to the local stakeholders and are expected to actively influence planning and regulation processes.

Membrane Filtration of Wastewater Split Flows originating from Paper Industry and Biological Wastewater Treatment of the generated Membrane Concentrates
© DIV Deutscher Industrieverlag GmbH (9/2011)
Wastewater effluents from deinking- and TMP processes were taken and were concentrated in 2 stages consisting of ultra- and nanofi ltration. Futher more, the concentrates were biologically treated with a single aerobic and a hybrid anaerobic-aerobic process. With a continuous anaerobic reactor and an aerobic SBR reactor experiments were conducted to study the variations in hydraulic retention time (HRT), food to biomass ratio (F/M) and wastewater concentrate. For the deinking wastewater concentrate, an overall average COD elimination of 51 % and 57 % was achieved for aerobic and anaerobic-aerobic treatment, respectively. Single stage aerobic treatment of TMP wastewater concentrate had an mean COD elimination effi ciency of 61 % and the hybrid anaerobic-aerobic treatment yielded 73 %. The temperature in the aerobic biological SBR reactor was kept stable at 30 °C with an F/M ratio between 0.01 and 0.5 gBOD5/(gSS · d).

Experimental Investigation of the Effect of Flip Bucket Splitters on Plunge Pool Geometry
© Springer Vieweg | Springer Fachmedien Wiesbaden GmbH (4/2010)
Flip buckets are common hydraulic structures aiming at deflecting high velocity flows to a free jet trajectory. Systematic experimental tests have been performed to assess the influence on energy dissipation and the plunge pool geometry of varied repartitions of splitters along the flip bucket width. In particular, it is shown that some configurations can create more erosion than a continuous channel without flip bucket.

Energy efficient process for xylene isomer separation: The use of nanocomposite MFI-ceramic hollow fibres
© Aristotle University of Thessaloniki (6/2009)
The use of hollow fibre geometry has long been a solution for improving the performance of lessenergy intensive membrane-based separation processes. Industrial application of this type of configuration is known in water treatment where polymer hollow fibres are commonly used. However polymer hollow fibres are thermally and chemically unstable and thus insuitable for high temperature applications.

Sorption kinetics of PAH by using various sorbents
© Aristotle University of Thessaloniki (6/2009)
Polycyclic aromatic hyrocarbons (PAH), which are a large group of organic compounds with two or more fused rings, are an important threat to the environment. They occur in the aquatic environment as the result of oil spills, ship traffic, pyrolytic processes, domestic and industrial wastewater discharges.



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