Simeone Chianese

Steam gasification of refuse-derived fuel in a rotary kiln pilot plant: Experimental tests

Refuse-derived fuel (RDF) steam gasification tests were performed in a rotary kiln pilot plant. The gas features were evaluated by varying the feeding ratio (FR), in the range 0.4-2.67, at a constant temperature equal to 850 °C. Several experimental tests were carried out in order to evaluate the best values for the main operating variables: kiln temperature, gas and solid residence time, etc., before evaluating the effect of the FR increase on the gas energy content and composition. Results show that the gas energy content decreases as the FR increases and, in the range of the FR studied, it achieves the maximum for FR=0.4, which corresponds to a volumetric gas composition of H2=59.1 %vv, CO=16.8 %v/v, CO2=20.1 %v/v, CH4=3 %v/v (not considering N2) and the highest lower heating value (LHV) equal to 16 MJ kggas -1 is obtained.

Ibuprofen degradation in aqueous solution by using UV light

AbstractRecent regulation policies are focusing on the presence of priority and emerging pollutants in water, among them, pharmaceutical residues are of particular public concern since trace of these molecules is commonly found in drinking and superficial waters. Progresses in innovative technologies for wastewater treatment are mandatory in order to improve their abatement efficiencies for water source prevention and reclamation. The OH-based technologies, a group of different techniques usually called advanced oxidation processes (AOPs), can be used to mineralize organic pollutants. In particular, combined treatments based on UV light appear to be more eco-friendly, also giving very interesting removal efficiencies if opportunely devised. Moreover, many of the commonly detected pharmaceutical compounds are susceptible to degradation by UV at disinfection doses. In this paper, the removal of ibuprofen (IBP)—a widely used non-steroidal anti-inflammatory drug (NSAID)—from synthetic water streams was explor...

Application of a discontinuous permeable adsorptive barrier for aquifer remediation. A comparison with a continuous adsorptive barrier

AbstractThis work presents an innovative configuration of a permeable adsorptive barrier (PAB) for the in situ remediation of benzene-contaminated groundwater in the area of Naples (Italy). A PAB is a type of permeable reactive barrier (PRB) made with adsorbing materials (e.g. activated carbon). This particular PAB is a discontinuous permeable adsorptive barrier (PAB-D), consisting in an array of deep passive adsorptive wells whose hydraulic conductivity is higher than the surrounding soil. The design was based on COMSOL Multi-physics® simulations, which allow for the description of pollutant transport in groundwater and adsorption onto the barrier by means of a 2D model solved using a finite element approach. Based on a hydrological and geotechnical characterization of the entire polluted aquifer, the design and optimization of PAB-D parameters (location, orientation, number of wells and dimensions) were defined. The influence of hydraulic conductivity and dispersivity on the total number of wells for a ...

Experimental and simulation study of the restoration of a thallium (I)-contaminated aquifer by Permeable Adsorptive Barriers (PABs)

Permeable Adsorptive Barriers (PABs), filled with a commercial activated carbon, are tested as a technique for the remediation of a thallium (I)-contaminated aquifer located in the south of Italy. Thallium adsorption capacity of the activated carbon is experimentally determined through dedicated laboratory tests, allowing to obtain the main modelling parameters to describe the adsorption phenomena within the barrier. A 2D numerical model, solved by using a finite element approach via COMSOL Multi-physics®, is used to simulate the contaminant transport within the aquifer and for the PAB design. Investigations are carried out on an innovative barrier configuration, called Discontinuous Permeable Adsorptive Barrier (PAB-D). In addition, an optimization procedure is followed to determine the optimum PAB-D parameters, and to evaluate the total costs of the intervention. A PAB-D made by an array of wells having a diameter of 1.5m and spaced at a distance of 4m from each other, is shown to be the most cost-effective of those tested, and ensures the aquifer restoration within 80years. The simulation outcomes demonstrate that the designed PAB-D is an effective tool for the remediation of the aquifer under analysis, since the contaminant concentration downstream of the barrier is below the thallium regulatory limit for groundwater, also accounting for possible desorption phenomena. Finally, the best PAB-D configuration is compared with a continuous barrier (PAB-C), resulting in a 32% saving of adsorbing material volume, and 36% of the overall costs for the PAB-D.

Extraction of astaxanthin from microalga Haematococcus pluvialis in red phase by using generally recognized as safe solvents and accelerated extraction

Solvent Extraction was tested to extract astaxanthin from Haematococcus pluvialis in red phase (HPR), by investigating effects of solvents, extraction pressure and temperature. Astaxanthin isomers were identified and quantified in the extract. The performances of acetone and ethanol, Generally Recognized As Safe (GRAS) solvents, were explored. Negligible effect of pressure was found, while with increasing extraction temperature astaxanthin recovery increased till a maximum value, beyond which thermal degradation seemed to be greater than the positive effect of temperature on extraction. Furthermore, to maximize the extraction yield of astaxanthin, mechanical pre-treatment of HPR biomass was carried out and several extraction runs were consecutively performed. Experimental results showed that after the mechanical pre-treatment the astaxanthin recovery strongly increased while a single extraction run of 20 min was sufficient to extract more than 99% of total astaxanthin extracted. After pre-treatment, maximum recovery of about 87% was found for acetone (pressure = 100 bar; temperature = 40 °C; total time = 60 min).

Ni-Ti Shape Memory Alloy Coatings for Structural Applications: Optimization of HVOF Spraying Parameters

This work aims at contributing to the development of a revolutionary technology based on shape memory alloy (SMA) coatings deposited on-site to large-scale metallic structural elements, which operate in extreme environmental conditions, such as steel bridges and buildings. The proposed technology will contribute to improve the integrity of metallic civil structures, to alter and control their mechanical properties by external stimuli, to contribute to the stiffness and rigidity of an elastic metallic structure, to safely withstand the expected loading conditions, and to provide corrosion protection. To prove the feasibility of the concept, investigations were carried out by depositing commercial NiTinol Ni50.8Ti (at.%) powder, onto stainless steel substrates by using high-velocity oxygen-fuel thermal spray technology. While the NiTinol has been known since decades, this intermetallic alloy, as well as no other alloy, was ever used as the SMA-coating material. Due to the influence of dynamics of spraying and the impact energy of the powder particles on the properties of thermally sprayed coatings, the effects of the main spray parameters, namely, spray distance, fuel-to-oxygen feed rate ratio, and coating thickness, on the quality and properties of the coating, in terms of hardness, adhesion, roughness, and microstructure, were investigated.

Super-paramagnetic Nanoparticles: Manufacturing, Structure, Properties, Simulation, Applications

Super-Paramagnetic Nanoparticles: Manufacturing, Structure, Properties, Simulation, Applications Baja Adamaki, Despoina Karatza, Simeone Chianese, Dino Musmarra*, Eleni Metaxa, Evangelos Hristoforou Laboratory of Physical Metallurgy, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece Dipartimento di Ingegneria Civile, Design, Edilizia e Ambiente, Seconda Università degli Studi di Napoli, Via Roma 9, 81031 Aversa (CE) dino.musmarra@unina2.it

Development and Characterization of High Performance Shape Memory Alloy Coatings for Structural Aerospace Applications

This paper presents an innovative approach, which enables control of the mechanical properties of metallic components by external stimuli to improve the mechanical behavior of aluminum structures in aeronautical applications. The approach is based on the exploitation of the shape memory effect of novel Shape Memory Alloy (SMA) coatings deposited on metallic structural components, for the purpose of relaxing the stress of underlying structures by simple heating at field-feasible temperatures, therefore enhancing their structural integrity and increasing their stiffness and rigidity while allowing them to withstand expected loading conditions safely. Numerical analysis provided an insight in the expected response of the SMA coating and of the SMA-coated element, while the dependence of alloy composition and heat treatment on the experienced shape memory effect were investigated experimentally. A two-phase process is proposed for deposition of the SMA coating in an order that induces beneficial stress relaxation to the underlying structure through the shape memory effect.

Supercritical Carbon Dioxide Extraction of Astaxanthin, Lutein, and Fatty Acids from Haematococcus pluvialis Microalgae

Haematococcus pluvialis microalgae in the red phase can produce significant amounts of astaxanthin, lutein, and fatty acids (FAs), which are valuable antioxidants in nutraceutics and cosmetics. Extraction of astaxanthin, lutein, and FAs from disrupted biomass of the H. pluvialis red phase using carbon dioxide (CO2) in supercritical fluid extraction (SFE) conditions was investigated using a bench-scale reactor in a semi-batch configuration. In particular, the effect of extraction time (20, 40, 60, 80, and 120 min), CO2 flow rate (3.62 and 14.48 g/min) temperature (50, 65, and 80 °C), and pressure (100, 400, and 550 bar.) was explored. The results show the maximum recovery of astaxanthin and lutein achieved were 98.6% and 52.3%, respectively, at 50 °C and 550 bars, while the maximum recovery of FAs attained was 93.2% at 65 °C and 550 bars.

DMA Optimal Layout for Protection of Water Distribution Networks from Malicious Attack

Water distribution networks (WDNs) are among the most important civil networks, because they deliver drinking and industrial water to metropolitan areas, supporting economic prosperity and quality of life. Therefore, they constitute critical infrastructures (CIs) as systems whose operability are of crucial importance to ensure social survival and welfare. In the last years, extreme natural events and intentional malicious attacks have shown that global safeguard of systems cannot be ever performed. In this regard, critical infrastructure protection (CIP) strategies should be focused both on the prevention of these events and on the procedures for the functioning recovery and damage limitation. In this paper, starting from previous works of the authors, the impact of an intentional contamination attack to water distribution network and a possible strategy to mitigate the user risk have been studied, simulating the introduction of potassium cyanide with a backflow attack into water system. As protection technique, the water network partitioning (WNP) has been adopted in order to improve the management and also to reduce the extent of damage showing a dual use-value. WNP reveals to be an efficient way to protect water networks from malicious contamination, through the closure of gate valves by a remote control system creating semi-independent District Meter Areas (DMAs). The study also investigates the possibility to identify a priori the most critical point of a water distribution network for the malicious attack through a novel procedure based on topological metric. The methodology, tested on a real medium size water network in Italy, shows very interesting results in terms of mitigation risk.