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Abstract: Green chemistry (GC) is the key to sustainable development as it will lead to new solutions to existing problems. Moreover, it will present opportunities for new processes and products and at its heart is scientific and technological innovation. This paper aims to contribute to a better understanding of the new challenges that chemistry is facing. A particular emphasis is accorded to the need for the development of environmentally friendly technologies for water treatment where GC can be satisfied. Indeed, following the establishment of the 12 Principles of GC, there has been a steady growth in our understanding of what GC means. Furthermore, there are great perspectives relating to the greening of chemical water treatment, especially in terms of ferrate(VI) adding, as oxidant/disinfectant/coagulant in the same time, and microchannel reactors which would be considered as promising devices for water treatment due to their proved advantages. [Copyright &y& Elsevier]

Abstract: Chemical water treatment problems such as disinfection by-products formation have urged on the search of better water treatment technologies such as electrochemical water technologies which have been applied successfully in different water/wastewater pollutant removal. However, their wide extension is hindered by some technical problems such as chlorine by-products (CBPs) generated species. Indeed, during electrochemical process, these carcinogenic substances may be formed depending on the electrode material and applied voltage. This review concerns the dependence of CBPs generated species formation of the electrode material and applied charge during electrochemical water treatment. It is concluded that the use of electrodes producing highly reactive species must be more carefully controlled in hygienically and environmentally oriented applications. From this point of view, Pt and boron-doped diamond (BDD) anodes are proved more convenient than other electrodes. Indeed, the great capability of a BDD anode to produce reactive oxygen species and other oxidising species during the electrolysis allows establishing a chlorine-free disinfection process. [Copyright &y& Elsevier]

This work uses thermogravimetric analysis to perform the thermokinetics and thermodynamic studies of Syagrus romanzoffiana fibers (SRFs). In a nitrogen environment, SRFs were heated non-isothermally between 25 and 800 °C at four heating rates of 5 °C/min, 10 °C/min, 15 °C/min, and 20 °C/min. According to thermogravimetric examination, the pyrolysis of SRFs occurred in three steps. The second stage has had its kinetic and thermodynamic characteristics determined. The low-temperature stable components were decomposed at temperatures ranging from 218 to 376 °C, 218–391 °C, 218–394 °C, and 218–398 °C at heating rates of 5 °C/min, 10 °C/min, 15 °C/min, and 20 °C/min, respectively. The Coats-Redfern method was applied to twenty-one distinct kinetic models representing four key solid-phase reaction processes. The diffusion model using the Zhuravlev equation is the best-fitted model, having the most outstanding correlation coefficient values (R 2 > 0.99) for all heating rates. Heating rates of 5, 10, 15, and 20 °C/min resulted in activation energy values of 114.02, 118.77, 119.44, and 113.89 kJ/mol, respectively. Thermodynamic characteristics (Δ H , Δ G , and Δ S) were computed using kinetic parameters. The data presented here helps evaluate SRFs as a possible biomass renewable energy source for building reactors and generating chemicals. • The pyrolysis kinetics of Syagrus romanzoffiana fibers (SRFs) is studied. • Kinetic parameters at low temperatures were determined by the Coats-Redfern method. • Different models were evaluated and followed by varied heating rates. • Thermodynamic analysis of SRFs pyrolysis is carried out. • SRFs are promising for biomass energy and biocomposite development opportunities. [ABSTRACT FROM AUTHOR]

The formation and conservation of renewable radiation into chemical fuels via photocatalytic water splitting (WS) maintains a perspective for maximizing the economic condition and limiting the worldwide climate consequence. Photocatalytic water splitting (PWS) employing powdered semiconductors has enormous opportunity for sustainable fuel, since this crossroad connecting biological, material science, and physical sciences depicts a field with exciting multidisciplinary issues. Development in PWS has been accomplished in past decades, encompassing from basic science investigation to innovative extensible technologies. Semiconductor-based photocatalysis is regarded as a potential sustainable solution. In this regard, graphitic carbon nitride (g-C 3 N 4) is classed as a metal-free photocatalyst to overcome this energy demand and ecological challenges, because of its superior electronic structure with band energy of around 2.7 eV, strong photochemical stabilization, and higher light efficiency. The photocatalytic activity of g-C 3 N 4 is inadequate, because of its small surface area (SA) and high rate of charge recombination. Various chemical alteration techniques have been developed to address such problems, broaden the functionality ranges, and improve the characteristics of g-C 3 N 4. The present review provides an in-depth evaluation of the chemical modification techniques for g-C 3 N 4 , comprising covalently and non-covalently techniques. Covalent techniques demonstrate the formation of chemical bonding among the g-C 3 N 4 configuration and the chemical activator via oxidation/carboxylation, amidation, composite inoculation, etc., even though non-covalent techniques entail the formation of physiological bonds and interfacial properties via van der Waals connections, hydrophobic forces, etc. After these fabrication approaches, the photocatalytic performance increased due to the generation of photoinduced electrons and holes, improved light absorption ability, and boosted SA, which provides more space for photocatalytic reaction. In this review, various metals, non-metals, metals oxide, sulfides, and ferrites have been integrated with g-C 3 N 4 to form mono, bimetallic, heterojunction, Z-scheme, and S-scheme-based materials for boosting the photocatalytic performance. Also, different varieties of g–C 3 N 4 –based materials have been utilized for different aspects of photocatalytic applications such as water reduction (HER), water oxidation (OER), and overall water splitting (OWS). Therefore, we have assembled a summary of the latest modern g-C 3 N 4 nanocomposites, as well as their uses in solar energy adaptation and environmental management. This research explains the details of the mechanism for all these photocatalytic processes for the next steps, as well as many new insights to overcome the current challenges. Proposed illustration of the overview of the current aspect of g-C 3 N 4. [Display omitted] • The g-C 3 N 4 is a metal-free photocatalyst (∼2.7 eV), with strong photochemical stabilization. • The chemical modification techniques have been discussed in detail. • Advanced fabrication approaches have been discussed briefly. • Specific properties and physicochemical aspects have been depicted briefly. • Potential photocatalytic applications have been discussed in detail. [ABSTRACT FROM AUTHOR]