The \"asbestos problem\" arises from the fact that asbestos is still abundant in many buildings and represents a hazard for human health. Current strategies adopted by law aiming at mitigating this hazard are far from being ideal. A smarter solution would be an energy sustainable detoxification treatment followed by recycling. If adopted, it would preserve the environment from pollution, natural resources from depletion and human health from hazard. Asbestos-cement slates were thermally deactivated through a sustainable process and reused in mortar for plaster applications. We found that the addition up to 7 wt% of the deactivated product does not affect significantly the water demand; does not affect thixotropy, stickiness and spreadability of the plastic mixture; slightly increases the strength of the mortar; does not compromise mechanical properties after aging. Considering the huge amount of traditional mortar employed worldwide, a rapid end of the \"asbestos problem\" is envisaged.

The thermal deactivation of diesel soot particles exerts a significant influence on the control strategy for the regeneration of diesel particulate filters (DPFs). This work focused on the changes in the surface functional groups, carbon chemical state, and graphitization degree during thermal treatment in an inert gas environment at intermediate temperatures of 600°C, 800°C, and 1000°C and explore the chemical species that were desorbed from the diesel soot surface during thermal treatment using a thermogravimetric analyser coupled with a gas-chromatograph mass spectrometer (TGA-GC/MS). The surface functional groups and carbon chemical state were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The graphitization degree was evaluated by means of Raman spectroscopy (RS). The concentrations of aliphatic C-H, C-OH, C=O, and O-C=O groups are reduced for diesel soot and carbon black when increasing the thermal treatment temperature, while the sp2/sp3 hybridized ratio and graphitization degree enhance. These results provide comprehensive evidence of the decreased reactivity of soot samples. Among oxygenated functional groups, the percentage reduction during thermal treatment is the largest for the O-C=O groups owing to its worst thermodynamic stability. TGA-GC/MS results show that the aliphatic and aromatic chains and oxygenated species would be desorbed from the soot surface during 1000°C thermal treatment of diesel soot.

Nowadays, asbestos-containing wastes (ACW) still represent an important environmental problem and a severe health hazard due to the well known pulmonary diseases derived from asbestos fibers inhalation. Except for a very few cases, ACW are currently confined in controlled landfills, giving rise to increasingly high amounts of still hazardous wastes. A promising alternative to landfill confinement is represented by ACW inertization, but the high cost of the inertization processes so far proposed by the scientific community have hampered the creation of actually operative plants. In this paper, we explore the possibility to use an innovative process that ensures the obtainment of asbestos-free inert material in an exceptionally short processing time, thus greatly reducing cost-related problems. The efficacy of the inertization process has been verified through accurate mineralogical investigations on both chrysotile and crocidolite de-activated fibers, through X-ray diffraction, scanning and transmission electron microscopy. Overall mineralogical, microstructural and granulometric characteristics of the inert bulk material suggest that it could be successfully re-used as a secondary raw material in ceramic industries. This innovative inertization procedure could therefore provide an effective and economically sustainable solution for ACW management.

The stability and thermodynamic properties of an enzyme are the main factors that governing its applications in industry. With that intention we have immobilized the α-amylase onto synthesized chitosan-magnetite (CSM) composite and its modified forms by gluteraldehyde (CSM-GLA), glyoxal (CSM-GLY) and epichlorohydrin (CSM-ECH). In this study all the immobilized enzymes exhibited improved pH stability about 60-80% of relative activity at pH 9 compared to the free enzyme. The temperature stability at 60 °C is up to 50% of relative activity for covalently immobilized enzymes as enzyme become more rigid by covalent binding and so protected from the conformational changes caused by the environment. The thermal deactivation of the free and immobilized enzymes follows the first order kinetics. The t1/2 and D-values were prolonged considerably in case of covalently immobilized enzymes, indicating better thermal stability than that of free and adsorbed ones. The Ed values 18.71, 32.00, 27.19 and 20.46 KJmol-1 for CSM-E, CSM-GLY-E, CSM-GLA-E and CSM-ECH-E described the high stability and resistance to heat inactivation. The Km values 0.525 ± 0.04, 0.57 ± 0.06, 0.65 ± 0.04 mg/mL and Vmax values 25 ± 0.06, 19.6 ± 0.02, 16.39 ± 0.01 μmol mg-1 min-1for CSM-GLY-E, CSM-GLA-E and CSM-ECH-E showing better substrate affinity. The immobilized enzymes have exhibited about 60% of relative activity after 90 days of storage and very good reuse potential.

A multi-analytical methodology is implemented to characterize several sieving fractions of industrial samples of Black Mass (BM) powders originating from the thermo-mechanical treatment of cylindrical and prismatic-type spent nickel metal-hydride (Ni-MH) batteries. Elemental analyses of 17 elements (including C and O) indicate that the elemental composition of the powders (greater than93 %wt) does not depend on the battery type nor on the sieving fraction. XRD analyses evidence several phases (including Ni, NiO, CeO2 and C) but their quantification is not possible. Beyond these standard characterisations, magnetic susceptibility measurements demonstrate that the amount of metallic nickel versus nickel oxide increases with the sieving fraction, and that powders from prismatic-type batteries contain twice as much metallic nickel than cylindrical ones. Thanks to statistical analysis (based on clustering algorithms) of an electron probe µ-analysis (EPMA) compositional map, the complete methodology allows us to propose a full phase distribution for the BM particles. Three types of particles are identified and quantified. They originate from the partial oxidation of the battery components (anode active mass, anode current collector, cathode active mass and cathode current collector). The whole picture highlights the joint importance of battery ageing mechanisms, thermal deactivation and BM sieving steps on powder composition.

In this article, the photo-deactivation mechanism of dual emission of a neutral iridium (III) complex is explored by using density function theory (DFT) and time-dependent density function theory (TD-DFT) calculations. To explore the phosphorescence quantum yield of the iridium (III) complex, the radiative decay constant of each emission excited state was computed by TD-DFT calculations, including spin-orbit coupling (SOC). In these calculations, factors such as the transition dipole moments, energy gaps, and SOC elements between the emission states and singlet excited states are taken into account in the evaluation of the radiative decay constants. Additionally, the non-radiative decay is revealed by considering the temperature-independent and the temperature-dependent non-radiative processes. The computational results indicate that the order of the two emission excited states can exert a significant effect on the phosphorescence quantum yield, which is beneficial for understanding the properties of photo-deactivation of phosphorescent emitters.

The aim of this research was the partial characterization of polygalacturonase (PG) extracts produced by a newly isolated Penicillium brasilianum and Aspergillus niger in submerged fermentation. The partial characterization of the crude enzymatic extracts showed optimum activity at pH 5.5 and 37 °C for both extracts. The results of temperature stability showed that PG from both microorganisms were more stable at 55 °C. However, the enzyme obtained by P. brasilianum presents a half-life time (t 1/2 = 693.10 h), about one order of magnitude higher than those observed in for A. niger at 55 °C. In terms of pH stability, the PG produced by P. brasilianum presented higher stability at pH 4.0 and 5.0, while the PG from A. niger showed higher stability at pH 5.0.