Search results for "Science and technology"
showing 10 items of 1592 documents
Simulation of a regeneration plant for spent pickling solutions via spray roasting
2015
Nowadays, pyrohydrolysis techniques are widely applied for regeneration of spent pickling liquors providing an excellent environmental and economical strategy to the problem of waste disposal/recovery, also thanks to the high acid recovery efficiencies (>99%) achieved. In fact, in these processes, iron chlorides are converted into iron oxides and hydrogen chloride at high temperature in spray roasting or fluidized bed reactors. Though the state-of-the-art technologies have been successfully applied only to large-scale plants, the development of small-scale units, able to perform a delocalized regeneration of spent solutions where these latter are actually produced, would be strongly needed …
Sulphate-Reducing Laboratory-Scale High-Rate Anaerobic Reactors for Treatment of Metal- and Sulphate-Containing Mine Wastewater
2002
Upflow anaerobic sludge blanket (UASB) reactors were used in this study to evaluate the feasibility of the sulphate-reducing, anaerobic high-rate process to treat metal- and sulphate-containing mining wastewater (MWW). Four simultaneous reactors, inoculated with different inocula (mesophilic granular sludge from two UASB reactors, one treating sugar refinery wastewater and the other board mill wastewater) and operated with different loadings, were for 95 days fed with synthetic feed consisting of glucose and sulphate. In all reactors, 23-72% of sulphate and 12-93% of COD were removed. Subsequently, two reactors were fed with diluted MWW (zinc as the main metal) for 77 days with hydraulic re…
Water Resource Recovery Facilities (WRRFs): The Case Study of Palermo University (Italy)
2021
The wastewater sector paradigm is shifting from wastewater treatment to resource recovery. In addition, concerns regarding sustainability during the operation have increased. In this sense, there is a need to break barriers (i.e., social, economic, technological, legal, etc.) for moving forward towards water resource recovery facilities and demonstration case studies can be very effective and insightful. This paper presents a new water resource recovery case study which is part of the Horizon 2020 EU Project “Achieving wider uptake of water-smart solutions—Wider Uptake”. The final aim is to demonstrate the importance of a resource recovery system based on the circular economy concept. The r…
Salmo salar fish waste oil: Fatty acids composition and antibacterial activity
2020
Background and aims Fish by-products are generally used to produce fishmeal or fertilizers, with fish oil as a by-product. Despite their importance, fish wastes are still poorly explored and characterized and more studies are needed to reveal their potentiality. The goal of the present study was to qualitatively characterize and investigate the antimicrobial effects of the fish oil extracted from Salmo salar waste samples and to evaluate the potential use of these compounds for treating pathogen infections. Methods Salmo salar waste samples were divided in two groups: heads and soft tissues. Fatty acids composition, and in particular the content in saturated (SAFAs), mono-unsaturated (MUFA…
Aerobic granular sludge reactor treating anaerobically pretreated brewery wastewater at different loading rates
2018
Small and medium breweries discharging to municipal sewers without treatment generate significant loads with typical concentrations reported by Valta et al. (2014) as 2-6 g COD L-1, 25-80 mg TN L-1, 10-50 mg TP L-1, with pH between 4.5 and 12. Treatment of the high-strength wastewater requires specialized low footprint processes, such as aerobic granular sludge (AGS), capable of high-rate degradation, as well as simultaneous nitrogen and phosphorous removal (Wang et al., 2007). The objective of this study was to evaluate the start-up period of AGS receiving brewery wastewater after initial anaerobic pretreatment.
The state of water resources in major mediterranean islands
2014
This work analyses the state of water resources in six Mediterranean islands: Corsica, Crete, Cyprus, Mallorca, Malta and Sicily. The analysis is focused on the prevailing social, economic and hydroclimatological characteristics of these islands in order to identify the main common features affecting water availability, demand and use. A detailed analysis of the state of water resources in all the considered islands has been carried out. A background of current conditions relating to freshwater availability, quality and use has been established. Different strategies to face water scarcity and enhance water quality in theislands have been assessed in a context of climate change which is a co…
Utilisation de dérayures de cuir tanné au chrome pour la décontamination des eaux polluées par les colorants et les huiles
2007
Abstract Les dérayures du cuir ont montré une grande capacité d'adsorption des colorants organiques directs. La capacité maximale de rétention est de 333,3 mg/g et de 312,5 mg/g respectivement pour les colorants DR75 et DR80. Un pH acide et une température de l'ordre de 50°C sont favorables à la décoloration. Les essais ont révélé la faisabilité de la décontamination d'un rejet de textile par les dérayures. Le taux d'épuration peut dépasser 90 p.100 dans des conditions précises de pH et de température. Les dérayures brutes et saturées par le colorant DR80 ont montré également une grande capacité d'absorption des huiles (5 à 6,5 g/g). En milieu aqueux, ces déchets fibreux réagissent fortemen…
Three-dimensional numerical simulation of wind-driven flows in closed channels and basins
2005
In the paper, a fully 3D finite-volume numerical model is developed and employed for the prediction of wind-induced flows in a regular channel and in a square basin with a complex bathymetry. Numerical results are compared with laboratory experiments. Numerical tests are then performed to investigate whether simplifying assumptions about the pressure distribution and the turbulente stresses representation can be employed in the simulation of wind-driven flows. The hydrostatic pressure assumption, resulting in the use of "quasi-3D" models, proved to be reasonably acceptable in order to obtain the vertical profile of the streamwise velocity component away from the boundaries. The quasi-3D mod…
Comparing two methods to perform a beerkan infiltration run in a loam soil at different dates
2023
<p>Performing beerkan infiltration runs with different heights of water pouring could help to obtain saturated soil sorptivity, <em>S</em>, and hydraulic conductivity, <em>K<sub>s</sub></em>, data usable to explain and simulate hydrological processes. However, most of the available information on the L (low height of water pouring, nearly 3 cm) - H (high height, 1-2 m) methodology refers to runs making use of a relatively limited number of water volumes and there is some sign that a few water volumes could yield an incomplete description of soil alteration phenomena induced by wetting. For a lo…
Pixel-oriented land use classification in energy balance modelling
2012
Mass and energy transfer between soil, vegetation and atmosphere is the process that allows to maintain an adequate energy and water balance in the earth–atmosphere system. However, the evaluation of the energy balance components, such as the net radiation and the sensible and latent heat fluxes, is characterized by significant uncertainties related to both the dynamic nature of heat transfer processes and surfaces heterogeneity. Therefore, a detailed land use classification and an accurate evaluation of vegetation spatial distribution are required for an accurate estimation of these variables. For this purpose, in the present article, a pixel-oriented supervised classification was applied …