Search results for "Environmental engineering"
showing 10 items of 2674 documents
Shallow urban aquifers under hyper-recharge equatorial conditions and strong anthropogenic constrains. Implications in terms of groundwater resources…
2021
Abstract Humid equatorial regions are recognized as the least documented in term of hydrogeological functioning of aquifers despite the fact that they house a lot of developing countries and that groundwater is often the main water resource. Regarding this aspect, a study was conducted in sub-Saharan Africa, focusing on the Mio-Pliocene aquifer in Douala megacity (Cameroon) which is the rainiest city in West-Africa (about 4000 mm/year) with one of the greatest demographic growth rate of the African continent. Firstly, groundwater recharge rate has been calculated through water balance and Water Table Fluctuation methods. Results show that the aquifer is characterized by a high recharge of 6…
Behavior of rare earth elements in an aquifer perturbed by CO2 injection: Environmental implications
2019
International audience; Three cubic-meters of CO2-saturated water was injected into a subsurface fractured aquifer in a post-mined area, using a push-pull test protocol. Groundwater samples were collected before and after CO2-injection to quantify geochemical changes. CO2-injection initially reduced the pH of water from 7.3 to 5.7, led to the enrichment of major ions (Ca2+, Mg2+, and alkalinity), and dissolved trace metals (including Fe, Mn, As, and Zn) in the groundwater. Rare earth elements (REE) and yttrium concentrations were also measured in these samples before and after CO2 perturbation, to evaluate their behavior. An enrichment of total Y plus REE (REY) occurred. REY fractionation w…
Uncertainty in urban stormwater quality modelling: The effect of acceptability threshold in the GLUE methodology
2007
Uncertainty analysis in integrated urban drainage modelling is of growing importance in the field of water quality. However, only few studies deal with uncertainty quantification in urban drainage modelling; furthermore, the few existing studies mainly focus on quantitative sewer flow modelling rather than uncertainty in water quality aspects. In this context, the generalised likelihood uncertainty estimation (GLUE) methodology was applied for the evaluation of the uncertainty of an integrated urban drainage model and some of its subjective hypotheses have been explored. More specifically, the influence of the subjective choice of the acceptability threshold has been detected in order to ga…
Wind gustiness and sulphur dioxide concentration in the urban area of Barcelona, Spain
1991
Abstract Data on aerosols and wind parameters recorded at the Barcelona Meteorological Observatory were analysed to determine their relation to wind gustiness, defined according to the criteria used at Brookhaven National Laboratory. The relation between wind gustiness and wind speed and direction was analysed, together with the annual and monthly variation. The relation between the concentration of sulphur dioxide and wind gustiness was also investigated, and proved to be a very useful indicator in this kind of analysis, especially in local studies.
Environmental evidence of Valencia lagoon coastal barrier stabilization from 8500 BP to Present. Climate and eustatic variations
2020
Abstract The Albufera de Valencia is one of the largest lagoon in the Spanish Mediterranean. Two continuous borehole cores reaching depths of 8 and 14 m in the northern part of the lagoon underwent sedimentological, micropaleontological and biological study. The organic content was also analysed, and 14C radiometric dating and amino acid racemization were performed. Study of the content of benthic foraminifera and n-alkanes and alkanoic acids in the lagoon sedimentary record identified several periods. The core records showed seven different environments: alluvial; freshwater marsh; brackish marsh; brackish lagoon; brackish lagoon with marine connection, backbarrier flat, and backshore. The…
Encapsulation of Langerhans' islets: Microtechnological developments for transplantation
2011
There is an increasing trend to apply microsystems and microfluidics to solve medical and biomedical tasks. Microfluidic modules are used to modify and manipulate cells and cell clusters for therapeutic applications. Specifically, a method and technical system for encapsulation of Langerhans' islets as an option for the future treatment of diabetes mellitus is described. Type-1 diabetes patients suffer from an absolute lack of the hormone insulin caused by an autoimmune process destroying the Langerhans' islets. One way to restore glucose-dependent insulin secretion is the transplantation of human pancreatic islet cells (85% beta cells) from cadaveric donors. However, to prevent the rejecti…
Feasibility study of a combi-PV panel for greenhouse energy supply and water recovery by nightly radiation towards the sky
2011
In southern European areas, characterized by high irradiation, the use of water for both evaporative cooling systems and hydroponic fertigation, represents a serious drawback for crop cultivation under cover. Water recovery systems seem to be an attractive solution, especially when they are integrated in the greenhouse construction. In this research, a feasibility study of applying a water recovery system driven by a combi-PV panel, in a semi-closed greenhouse was carried out. The prototype combi-PV panel was made by coupling an amorphous silicon panel with a sump stacked on the rear PV panel surface and filled with saline water. The system is driven by a cold-heat sink which is the PV pane…
A social survey on the effects of environmental noise on the residents of Pamplona, Spain
1998
Abstract An extensive noise survey carried out in the city of Pamplona, Spain over 2 years has allowed us to elaborate a detailed daytime acoustic map of this city. The degree of noise annoyance in the community and its relationship with the measured noise levels has also been studied by means of a social survey.
The role of eutrophication reduction of two small man-made Mediterranean lagoons in the context of a broader remediation system: Effects on water qua…
2013
In order to meet the requirements of the European Union Water Framework Directive for the Albufera de Valencia (AV) Natural Park, in 2009, several areas of free water surface constructed wetlands (FWSCWs) planted with emergent vegetation and two small shallow lagoons planted with submerged macrophytes were created over a 40-ha area formerly occupied by rice fields. This area is currently a reserve known as Tancat de la Pipa. The dual goal of this programme was to improve the quality of the hyper-eutrophicated waters of the AV lagoon, the largest littoral lagoon in the Iberian Peninsula, and to restore former lost habitats to increase the biodiversity of the area. The lagoons were mainly fed…
Management of irrigation water and nutrient demands of tomato (Lycopersicon esculentum Mill.) using urban treated wastewater from a pilot-scale horiz…
2017
The reuse of treated wastewater (TWW) in crop irrigation is an advanced and rational approach to water resource management in agriculture. Results would seem to demonstrate that it could be an extremely important tool in the reduction of freshwater (FW) consumption in agriculture, at the same time helping to increase crop yields through the transfer of nutrients required for crop growth. In arid and semi-arid areas of the Mediterranean, constructed wetlands can play a key role in the treatment and reuse of wastewater due to their multifunctional nature. The aim of this study was to manage water and nutrient requirements of tomato (Lycopersicon esculentum Mill.) using TWW from a pilot-scale …