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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2006.08.021 Byline: Andres Navarro (a), Montserrat Carbonell (b) Keywords: Groundwater; Hydrogeochemistry; Urban environment; Nitrates; Heavy metals Abstract: The urban groundwater of the central BesA[sup.2]s river basin (the La Llagosta aquifer) has become contaminated due to the infiltration of wastewater from septic tanks and sewage networks, and by industrial activities located in urban areas. The groundwater hydrogeochemistry of the La Llagosta aquifer was characterized using isoconcentration maps, hydrogeochemical diagrams (Piper, Schoeller-Berkaloff) and by analyzing hydrogeochemical changes along a flow-path that crosses an urban and peripheral industrial area in the main alluvial aquifer (the La Llagosta unit). The evolution of cations, anions and heavy metals along the flow path and the use of the PHREEQC numerical code indicate a complex set of geochemical processes, which result from the interaction between the sources of pollution, the groundwater flow and the mineral composition of the aquifer materials. The contaminated groundwater below the urban areas shows high contents of NO.sub.3.sup.- (90-100mg/L) and an increase in the concentrations of Ca.sup.2+ and Mg.sup.2+ which coincides with a decrease in pH. The Eh shows greater variation than the pH along the flow line studied, with values ranging between 56mV in the industrial area and 370mV in the urban area. The area with the lowest Eh value coincides with the highest concentrations of dissolved Fe (4.7mg/L) and Mn (0.22mg/L). Author Affiliation: (a) Depto. M. Fluidos, ETSEIT, Universidad Politecnica de CataluA[+ or -]a, Colon 7, 08222 Terrassa, Spain (b) Depto. M. Fluidos, EPSEVG, Universidad Politecnica de CataluA[+ or -]a, Avd. Victor Balaguer s/n, 08800 Vilanova i la Geltru, Spain Article History: Received 21 April 2005; Revised 24 May 2006; Accepted 14 August 2006

A novel Kinetic Energy Harvester (KEH) has been developed for powering oceanic undrogued drifters. It consists on a double pendulum system capable of transforming the wave oscillations into rotation on a flywheel. This rotation is converted into DC current by an electrical generator and further processed by a power management unit (PMU). The PMU includes a “maximum power point tracking” system to maximize energy production by the generator. An oceanic drifter has also been designed to embed the KEH and a custom-made measurement system to perform real sea tests. It counts on an Inertial Measurement Unit to study the motion of the drifter and an embedded measurement system to estimate the rotation speed of the generator and the power at both the input and output of the PMU. A Wi-Fi connection is also included for data transfer at short distances. The generator was firstly characterized at the laboratory; the drifter was then placed on a linear shaker to assess its performance. Finally, the drifter was deployed in a controlled sea area with average values of wave height and frequency of 1.43 m and 0.29 Hz, respectively. In these conditions, the drifter showed horizontal and vertical oscillations with peak-to-peak accelerations of 0.8 g and power spectra centered around 1.5 Hz and 1 Hz, respectively. As a result, the KEH generated a mean output power of 0.18 mW, with peaks of 2.5 mW. [ABSTRACT FROM AUTHOR]

The aim of this paper is to elucidate the influence of the physical properties of both phases—solid matrix and saturating liquid—of bottom-heated porous media with an overlying plain water layer. The dryout, the stability of the system's water layer-vapor region, and the thermal state evolution are studied. The porous media under study are a bronze powder saturated by water, and a solution of surfactant and coarse sand saturated by the same liquids. From the experimental data obtained, a theoretical approach is carried out to describe the dryout and rewetting process. The influence of the nature and physical properties of the solid and liquid phases is also analyzed, with special attention to the addition of surfactant in the saturating liquid. [ABSTRACT FROM AUTHOR]

An anchored marine seismometer, acquiring real-time seismic data, has been built and tested. The system consists of an underwater seismometer, a surface buoy, and a mooring line that connects them. Inductive communication through the mooring line provides an inexpensive, reliable, and flexible solution. Prior to the deployment the dynamics of the system have been simulated numerically in order to find optimal materials, cables, buoys, and connections under critical marine conditions. The seismometer used is a high sensitivity triaxial broadband geophone able to measure low vibrational signals produced by the underwater seismic events. The power to operate the surface buoy is provided by solar panels. Additional batteries are needed for the underwater unit. In this paper we also present the first results and an earthquake detection of a prototype system that demonstrates the feasibility of this concept. The seismometer transmits continuous data at a rate of 1000 bps to a controller equipped with a radio link in the surface buoy. A GPS receiver on the surface buoy has been configured to perform accurate timestamps on the seismic data, which makes it possible to integrate the seismic data from these marine seismometers into the existing seismic network. [ABSTRACT FROM AUTHOR]

To evaluate the chemical recycling of plastic residues, co-pyrolysis of polypropylene (PP) waste with Brazilian crude oil was evaluated varying the temperature (400°C to 500°C) and the amount of PP fed to the reactor. The co-pyrolysis of plastic waste in an inert atmosphere provided around 80% of oil pyrolytic, and of these, half represent the fraction of diesel oil. This study can be used as a reference in chemical recycling of plastics, specially associated with plastics co-pyrolysis. [ABSTRACT FROM AUTHOR]