Laura E. Depero

Review of fly ash inertisation treatments and recycling

Fly ash (FA) is a by-product of power, and incineration plants operated either on coal and biomass, or on municipal solid waste. FA can be divided into coal fly ash, obtained from power plant burning coal, flue gas desulphurisation FA, that is, the by-product generated by the air pollution control equipment in coal-fired power plants to reduce the release of SO2, biomass FA produced in the plants for thermal conversion of biomass and municipal solid waste incineration (MSWI) FA, that is, the finest residue obtained from the scrubber system in a MSWI plant. Because of the large amount produced in the world, fly ash is now considered the world’s fifth largest material resource. The composition of FA is very variable, depending on its origins; then, also pollutants can be very different. In this frame, it is fundamental to exploit the chemical or physical potentials of FA constituents, thus rendering them second-life functionality. This review paper is addressed to FA typology, composition, treatment, recycling, functional reuse and metal and organic pollutants abatement. Because of the general growing of environmental awareness and increasing energy and material demand, it is expected that increasing recycling rates will reduce the pressure on demand for primary raw materials, help to reuse valuable materials which would otherwise be wasted and reduce energy consumption and greenhouse gas emissions from extraction and processing.

Supported ε and β iron oxide nanomaterials by chemical vapor deposition: structure, morphology and magnetic properties

Supported e- and β-Fe2O3 are synthesized by a chemical vapor deposition (CVD) strategy, yielding systems with controllable morphologies from nanorods (e) to square-like pyramids (β). The hard magnetic properties of e-Fe2O3 and the antiferro/paramagnetic behavior of β-Fe2O3 are directly influenced by the system morphological organization and structural orientations.

Structural and Mechanical Characterization of Sustainable Composites Based on Recycled and Stabilized Fly Ash

This paper reports the results on the use of an innovative inert, based on stabilized fly ash from municipal solid waste incineration as a filler for polypropylene. The starting material, which contains large quantities of leachable Pb and Zn, was stabilized by means of an innovative process using rice husk ash as a waste silica source, together with other fly ashes, such as coal fly ash and flue gas desulfurization residues. The use of all waste materials to obtain a new filler makes the proposed technology extremely sustainable and competitive. The new composites, obtained by using the stabilized material as a filler for polypropylene, were characterized and their mechanical properties were also investigated. A comparison with a traditional polypropylene and calcium carbonate based compound was also done. This research activity was realized in the frame of the COSMOS-RICE project, financed by the EU Commission.

Fluorine doped Fe2O3 nanostructures by a one-pot plasma-assisted strategy

The present work reports on the synthesis of fluorine doped Fe2O3 nanomaterials by a single-step plasma enhanced-chemical vapor deposition (PE-CVD) strategy. In particular, Fe(hfa)2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA = N,N,N′,N′-tetramethylethylenediamine) was used as molecular source for both Fe and F in Ar/O2 plasmas. The structure, morphology and chemical composition of the synthesized nanosystems were thoroughly analyzed by two-dimensional X-ray diffraction (XRD2), field emission-scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS) and transmission electron microscopy (TEM). A suitable choice of processing parameters enabled the selective formation of α-Fe2O3 nanomaterials, characterized by an homogeneous F doping, even at 100 °C. Interestingly, a simultaneous control of the system nanoscale organization and fluorine content could be achieved by varying the sole growth temperature. The tailored properties of the resulting materials can be favourably exploited for several technological applications, ranging from photocatalysis, to photoelectrochemical cells and gas sensing.

Fly Ash Pollutants, Treatment and Recycling

This chapter reviews fly ash typology, composition, treatment, deposition, recycling, functional re-use, and metals and organic pollutants abatement. Fly ash is a by-product of power and incineration plants operated either on coal and biomass, or municipal solid waste. The growing of environmental awareness and increasing energy and material demand will foster recycling. Recycling will help to reuse valuable materials which would otherwise be wasted, and reduce energy consumption and greenhouse gas emissions from extract ion and processing. Fly ash is world’s fifth largest material resource because of the large amount of ash produced in the world. Fly ash can be classified into several categories: coal fly ash obtained from power plant burning coal; flue gas desulphurisation fly ash, that is the byproduct generated by the air pollution control equipment in coal-fired power plants to prevent (reduce) the release of SO2; biomass fly ash produced in the thermal conversion of biomass; and municipal solid waste incineration (MSWI) fly ash, that is the finest residue obtained from the scrubber system in a municipal solid waste incineration plant.

Nanostructured TiO 2 and W:TiO 2 Thin Films by a Novel Sol-Gel Processing for Alcohol Sensing Devices

TiO 2 and W:TiO 2 thin films have been prepared by a chemically modified sol-gel technique , that implies hydrolysis and condensation of tetraethylortotitanate in the presence of a polymer dissolved in ethanol. Oxide-polymer films were deposited by dip-coating. Annealing at 500°C results in nanosized structurally stable oxides films. For doping tungsten(V)ethoxide was used in concentration that led to a final W/Ti atomic ratio of 1/33, 5/33, 10/33. The morphological and structural characteristics of thin films were studied through microraman, GIXRD, SEM and TEM. A microstructural comparison between pure and doped TiO 2 layers is reported. Ethanol and methanol sensing properties are tested.

Study of electrically conductive water-based polyurethane

S of the Problem: In order to understand the formation of strain-induced martensite (SIM) of austenitic stainless steels, phase textures were investigated both before and after static and cyclic loading, namely plastic deformation is made intentionally. Moreover, in-situ measurements of the strain-induced martensitic transformation that takes place during tensile loading at room temperature were performed. Even in the low plastic strain regime, with loading to yield stress, the SIM transformation occurred. However, the area fraction of the martensite formation did not increase significantly even when the sample was loaded to the ultimate tensile strength. On the other hand, by the cyclic loading, the area fraction of the martensite formation increases significantly when the maximum cyclic load is more than 80%UTS. In other word, the SIM formation is apparently absent when the samples are loaded with less than 70%UTS, although those samples are fractured completely. No clear frequency effect (1Hz vs. 30Hz) is detected. With the analysis, two different SIM characteristics were clarified following plastic deformation. The martensitic structures were obtained in the twin deformation and slip bands. The severity of martensite formation increased with increasing C content. It was found that martensite was formed mainly in austenitic stainless steel lacking Mo, whereas a high Mo content led to a strong martensite structure, i.e., a weak martensite. The formation of martensite occurred from austenite viamartensite, and was related to the slip deformation. The Mo element in austenitic stainless steel had high slip resistance (or stress-induced martensite transformation), due to the large size of the Mo atom. This resulted in the creation of weak martensite. The phase structures of the strained austenitic stainless steels were interpreted using a proposed, i.e., the martensitic transformations.We present various types of group III-nitride microand nano-structures for novel classical and quantum photonic applications. We demonstrate phosphor-less white-color light generation, unidirectional light propagation, ultrafast single photon generation, and room temperature exciton-polariton generation using these group III-nitride based photonic structures. First, multicolor and broadband visible light emitting diodes based on GaN hexagonal truncated pyramid and columnar structures were demonstrated [1, 2]. Second, by using GaN/InGaN core−shell QW semiconductors grown on tapered GaN rods, which have a large gradient in their bandgap energy along their growth direction, highly asymmetric photonic diode behavior was observed [3]. Third, we utilized a novel approach of the self-aligned deterministic coupling of single quantum dots (QDs) to nanofocused plasmonic modes, which enhances spontaneous emission rate of QDs as high as ~ 22 over a wide spectral range [4]. We also discuss about effective method for enhancing collection efficiency of the QDs formed in these photonic structures [5]. Finally, we developed a novel excitonpolariton system working at room temperature resulting from strong coupling between a two-dimensional exciton and whispering gallery mode photon using a core−shell hexagonal wire with GaN/InGaN multiple quantum wells [6]. An overview and comparison of the characteristics of the above nanostructures will be given.

Tin, Niobium and Vanadium mixed oxide thin films based gas sensors for chemical warfare agent attacks prevention

In this work we have studied the synthesis and characterization SnO2 thin films with varying Nb and V content for Sarin detection. As target molecule we used dimethyl methylphosphonate (DMMP), a Sarin nerve agent simulant. Nb and V oxides have been used because of their well-known catalytic properties. Results highlight that the proposed approach is suitable to develop sensors of DMMP at ppb level needed for security applications. Gas sensing performances have been investigated and the optimal Nb and V content for DMMP detection has been determined.