Sustainable Approach of Using Arundo donax Leaves Reinforced Cement Mortar/Fly Bottom Ash Composites.

Earlier research suggested using ash to substitute cement, whereas other studies looked at the possibility of using plant-derived agricultural wastes as fiber reinforcement in cement applications. This study offered an environmentally friendly option to change traditional mortars by replacing cement with fly bottom ash (FBA) waste at 10, 20, 30, and 40 wt %. Likewise, Arundo donax leaves (ADL) were employed to reinforce the modified cement mortars at 0.4, 2, 5, and 7 wt %. X-ray diffraction analysis of used materials was performed. The morphology of composites made with FBA and ADL was investigated using scanning electron microscopy. Moreover, the density, water uptake, thermal conductivity, energy gain, and carbon dioxide (CO2) emissions of the prepared composites were discussed. Their flexural strength, compressive strength, and displacement were also compared. Results revealed that the addition of FBA in the mortar matrix has a positive effect on decreasing the thermal conductivity and lightness of the mortar. In addition, 20 wt % of cement replacement by FBA guarantees simultaneously moderate mechanical properties, nearly 51% of energy gain, and 20% of total CO2 emission reduction. In the same, adding ADL to the 20wt %FBA mortar reduced the thermal conductivity and the lightness of the mortar. The 0.4 wt % ADL reinforcement ensured 59% energy gain and 6% of total CO2 emission reduction. A major amelioration was observed in the compressive strength (an increase of 14%) and in the plasticity (an increase of 27%) of the considered composite materials. In conclusion, using FBA as a cement replacement with low ADL content inclusion results in a thermal-resistant composite with reasonable durability and strength.

Pyrolysis of tea and coffee wastes: effect of physicochemical properties on kinetic and thermodynamic characteristics.

Physicochemical properties, kinetic pyrolysis and thermodynamic study of spent green tea, pure spent coffee grounds, spent coffee grounds blended with 50% torrefied barley and coffee husk were experimentally investigated using thermogravimetric analysis under an inert atmosphere to evaluate their thermochemical application. Five isoconversional methods were applied to determine effective activation energy (E a) of the pyrolysis processes. All methods showed good agreement by determining fluctuating E a values (150-500 kJ mol-1). Complex E a profiles with conversion were divided into four stages corresponding to thermal degradation of main biomass constituents (extractives, hemicellulose, cellulose and lignin), indicating that extractives decomposition was the least demanding reaction while lignin decomposition was the most demanding. The kinetic process was verified by reconstruction according to the Friedman parameters. The thermodynamic parameters were evaluated to determine the energy demand and efficiency throughout the process. The values obtained for physicochemical properties such as volatile matter (> 68%) and higher heating value (> 17 MJ kg-1), average E a (223-319 kJ mol-1) and significant energy efficiency implied that these types of biomass waste have significant reactivity and consequently the highest potential for the production of bioenergy and a range of high-value chemicals and materials. Supplementary Information: The online version contains supplementary material available at 10.1007/s10973-022-11878-4.

Fenton oxidation catalysed by heterogeneous iron-perlite for 8-hydroxyquinoline-5-sulfonic acid (8-HQS) degradation: efficiency comparison using raw and calcined perlite as precursors for iron fixation.

Herein, the catalytic activity of two types of iron-loaded perlite catalysts prepared by impregnation of raw and calcined perlite in terms of 8-hydroxyquinoline-5-sulfonic acid (8-HQS) degradation was investigated by the Fenton reaction. Different iron contents were used to optimize the Fenton catalytic reaction. The as-prepared catalysts were characterized using different spectrophotometry techniques. The effect of some operating parameters on the Fenton oxidation of 8-HQS was carried out. Iron content of 10% has led to the highest catalytic efficiency. Furthermore, the oxidation of 8-HQS is highly affected by the addition of H2O2, proposing that the heterogeneous Fenton reaction has been successfully activated. Whatever the type of the used catalyst, the heterogeneous catalytic oxidation process is extremely rapid, even instantaneous. The synthesized catalysts remained potentially active and retained their catalytic activity for successive Fenton reactions suggesting their economic benefit over the homogenous Fenton process. Accordingly, the newly prepared heterogeneous solid could be successfully used to treat wastewater effluents containing persistent organic compounds.