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Municipal solid waste incinerator fly ash (MSWI-FA) was used synergistically with volcanic ash (VA) to synthesize Geopolymer cement. The effects of the incorporation of 0%, 30%, and 50% of VA and the alkalinity of activating solution on the structure and properties were studied by using the X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field emission gun scanning electron microscopy (FEG-SEM), and mechanical testing. The encapsulation efficiency of the cements was carried out by using a toxicity characteristic leaching procedure (TCLP). The geopolymerization of MSWI-FA promoted the formation of new minerals such as Thernadite (Na 2 SO 4 ), Hydrocalumite (Ca 4 Al 2 O 6 (CO 3 ) 0.67 (SO 3 ) 0.33 ), C-S-H, and Faujasite-Na(Na 2 Ca) 0.075 (Al 0.3 Si 0.7 )O 2 (H 2 O) 0.22 . The Geopolymer cement synthesized with the addition of 50% of VA at 6M NaOH concentration, which exhibited the most compact microstructure. This was the highest strength with the best encapsulation ability. The microstructure analysis of the MSWI-FA-VA system revealed the coexistence of C-S-H and N-A-S-H phases as the main cementitious binders. The TCLP results of cement vis a vis raw MSWI-FA showed the leaching of metals reduced to a great extent. This was much lower than the permissible limit fixed by the United States Environmental Protection Agency (USEPA) for the toxicity characteristic. Furthermore, an attempt was made to correlate the microstructure with mechanical properties.Recycling 2018, 3, 50 2 of 14 of heavy metals content. Therefore, MSWI-FA is classified as a hazardous waste [3,4]. Owing to its chemistry, fine particle size, and pozzolanic behavior, MSWI-FA has the potential to be used as a mineral additive in cement. However, its high chlorine content restricts its application in construction material. Although the cement paste is not much affected by chloride except for increased solubilization of cement solids, chlorine is detrimental to the passivation of embedded steel [5]. To avoid this problem, some pre-treatment methods such as water washing and thermal treatment have been proposed [3,6,7]. These pre-treatments certainly eliminate the chlorides and inorganic salts in MSWI-FA but generate other wastes and increase the quantity of energy required for the synthesis and the total cost of the product. The efficient way to valorize MSWI-FA in construction is its use in the process, which displays limited signs of heavy metals leaching and the formation of the corrosion product in the presence of chlorine such as geopolymerization [8][9][10].Geopolymer cement are considered eco-friendly binder materials and potential alternative to Portland cement (OPC) in specific applications since they produce around 80% less CO 2 than Portland cement [11]. It has the potential to use alumina-silicate materials either from natural occurring waste, synthetic waste, or from industrial waste. Thus, varieties of alumina-silicate and industrial waste used for Geopolymer cement synthesis involve volcanic ash, glass powder,...

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We examined the structure-reaction enthalpies-antioxidant activity relationship of the molecule library built around juglone and its derivatives at B3LYP/6-31+G(d,p) level. Three major antioxidant mechanisms (hydrogen atom transfer (HAT), single electron transfer-proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET)) have been investigated in five solvents and in the gas phase. The delocalization of the unpaired electrons in the radicals or cation radicals has been explored by the natural bond orbital analysis and the interpretation of spin density maps. The results obtained have proven that the HAT mechanism is the thermodynamically preferred mechanism in the gas phase. But, in the solution phase, the SPLET mechanism has been shown to be more predominant than HAT. The reactivity order of compounds towards selected reactive oxygen species has also been studied.

Considerable interest has been shown in the development of biocomposite films for food packaging in recent years. In this study, biocomposite films based on polylactic acid (PLA) were prepared with varying levels of olive wood flour (OWF) (0, 1, 3, 5, and 10 wt%) using the solvent casting method. To achieve better dispersion, 2% ethanol was added during the casting of the biocomposite films. The effect of OWF content on the physicochemical and mechanical properties of the PLA films was investigated. Interaction between the OWF cellulose and the PLA matrix was revealed by FTIR spectroscopy analysis, and the addition of ethanol was found to be suitable for better dispersion of OWF, which resulted in decreased agglomeration rate in the biocomposites. The biocomposite films with the addition of 1% of OWF (OW1) exhibited the best dispersion, thermal stability, and tensile strength, with a gain of 31.07% (29.65 ± 6.6 MPa) and an increase in Young’s modulus of 15% (1199.18 ± 98 MPa). It was demonstrated that the properties of the PLA/OWF biocomposites make them suitable for green applications, including as film packaging for food products.