Search results for "Science and technology"

Environmental Benefit of Improving Wastewater Quality: A Shadow Prices Approach for Sensitive Areas

2018

The use of effluents from wastewater treatment plants (WWTPs) as a non-conventional source of water for wetlands in arid and semi-arid regions is becoming the most-often sought solution for maintaining water flow in sensitive wetlands there. However, the managing effluent quality should be a requirement because excess nutrients (mainly nitrogen and phosphorus) can generate eutrophication problems in wetlands. In the Mediterranean area in general, wetlands are strongly vulnerable to eutrophication, which is why they are classified as sensitive areas. Our study uses a data set from 24 WWTPs, effluents of which are discharged to wetlands in the coast of Community of Valencia. We use the shado…

Editorial: Special Issue on Economics of Wastewater Treatment and Reuse

2018

A numerical study of the Schumann resonances in Mars with the FDTD method

2007

[1] Natural electromagnetic waves generated near the surface by electrostatic discharges in dust storms (dust devils) or by geological activity could be trapped in the resonant cavity formed by the surface and lower ionosphere of Mars, as it occurs on Earth giving rise to Schumann resonances. The finite difference time-domain technique (FDTD) is applied to model the atmosphere of Mars in order to determine Schumann resonant frequencies, and natural electromagnetic fields at the extremely low frequency range (ELF). A numerical tool is provided to analyze the electrical conductivity profile of the Martian atmosphere, with the aim of obtaining Schumann resonance frequencies and their dependenc…

Giants and elephants of Sicily

2007

Computation of flow velocity in rough channels

2006

Accurate estimate of flow-velocity profile is of crucial importance both for scientific purposes and for solving numerous engineering problems that include, among others, sediment transport, contaminant transport, flow resistance evaluation. This paper presents a new empirical equation to represent the vertical velocity profile. The proposed equation is essentially a modified form of the well-known logarithm law of the wall and contains three parameters having a clear physical meaning. The applicability of the equation and its accuracy assessment for different hydraulic conditions, including non-uniform conditions, is verified by using experimental data obtained by different sources. The va…

Short-duration rainfalls in Sicily

1990

The Italian Hydrographic Service publishes yearly maximum rainfall depths with 1-, 3-, 6-, 12-, and 24-hr duration, recorded by recording rain gauges. It also publishes selected short-duration (t<1 hr) rainfall amounts. It is impossible to carry out a statistical analysis of the short-duration rainfalls for each recording rain gauge because the published data correspond to different record durations and to different recording rain gauges from year to year. Therefore, there is a practical need to derive empirical relationships between the 1-, 3-, 6-, 12-, and 24-hr duration amounts and shorter duration (t<1 hr) rainfall amounts. Such a relationship has been proposed by Bell and has been veri…

Geomaterials in green building practices: comparative characterization of commercially available clay-based plasters

2013

Three pre-mixed powdered clay-based (earthen) plasters produced in Europe and specifically designed for wall undercoating were analyzed in this paper. These materials are commercially available and successfully employed in green building practices all over the world. Their compositional and textural characteristics, as well as plastic behaviour were investigated through a multi-analytical approach: X-ray powder diffraction (XRPD), polarized light microscopy (PLM), X-ray fluorescence spectrometry (XRFS), scanning electron microscopy equipped with an energy dispersive spectrometer (SEM-EDS), mercury intrusion porosimetry (MIP), grain-size distribution (GSD) and semi-empirical tests (Atterberg…

Closed-form solutions of the energy balance equation for drip laterals under the Darcy-Weisbach resistance formula

2018

Many studies have investigated easy methods to design drip laterals, as well as the best resistance equation to use, which is fundamental to accurately account for friction losses. This paper addresses both the features of lateral design relationships and the influence of the friction-loss equation on the design variables. First, simple closed-form solutions of the energy balance equation for both sloped and horizontal drip laterals are derived with the simplified Darcy-Weisbach resistance formula by assuming the Darcy friction factor as invariant versus the Reynolds number. Second, an error analysis is performed assuming the friction factor as constant in the design, which is compared to u…

Anaerobic membrane bioreactors for resource recovery from municipal wastewater: a comprehensive review of recent advances

2021

[EN] In a paradigm shift towards a sustainable society based on the Circular Economy, wastewater treatments are rapidly evolving towards simultaneous recovery and reuse of clean water, renewable energy, and nutrients. This review examines recent advances (from 2016 to 2020) in the potential of anaerobic membrane bioreactors (AnMBRs) to serve as the core technology for municipal wastewater (MWW) resource recovery, focusing on the latest technological advances and economic and environmental innovation perspectives. The potentials and limitations of AnMBR for further full-scale application and new platforms to address these challenges are discussed, covering systems based on co-digestion, pre-…

Performance evaluation of hybrid RO/MEE systems powered by a WTE plant

2008

Abstract The solid waste management is, in different contexts, a very critical issue. The use of landfills can no longer be considered a satisfactory environmental solution, therefore new methods have to be chosen and waste-to-energy (WTE) plants would provide an answer. Today's WTE plants are a far cry from their polluting predecessors. Using modern combustion and pollution control technology, WTE plants are able to retrieve considerable amounts of energy from waste combustion while minimizing emissions. As we know, is possible to recover thermal energy by combusting municipal solid waste (MSW) for electricity generation and district heating. However, with everincreasing population and rap…