Biogenic silver based nanostructures: Synthesis, mechanistic approach and biological applications.

The alarming impact of antibiotic resistance sparked the quest for complementary treatments to overcome the confrontation over resistant pathogens. Metallic nanoparticles, especially silver nanoparticles (Ag NPs) have gained a much attention because of their remarkable biological characteristics. Moreover, their medicinal properties can be enhanced by preparing the composites with other materials. This article delves a comprehensive review of biosynthesis route for Ag NPs and their nanocomposites (NCs) with in-depth mechanism, methods and favorable experimental parameters. Comprehensive biological features Ag NPs such as antibacterial, antiviral, antifungal have been examined, with a focus on their potential uses in biomedicine and diagnostics has also been discussed. Additionally, we have also explored the hitches and potential outcomes of biosynthesis of Ag NPs in biomedical filed.

Recent progress in air treatment with combined photocatalytic/plasma processes: A review.

Nowadays, air pollution is an increasingly important topic, as environmental regulations require limiting pollutant emissions. This problem requires new techniques to reduce emissions by either improving the current emission control systems and processes or installing new hybrid treatment systems. These are of broad diversity, and every system has its advantages and disadvantages. The tendency is, accordingly, to combine various techniques to achieve more acceptable and suitable treatment. Recent studies suggest that the combination of photocatalysis and plasma in a reactor can offer attractive pollutant treatment efficiency with a minimum of partially oxidized by-products than that of these processes taken separately. However, there is little review of the capability of this pairing to treat different brands of pollutants. Besides, available data concerning reactor design with flows treated 10 to 1000 times higher than those studied at the lab scale. This review paid particular attention to determine the reaction mechanisms in terms of engineering and design of combination reactors (plasma and catalysis). Likewise, we developed the effect of critical parameters such as pollutant load, relative humidity, and flow rate to understand the degradation kinetics of specific pollutants individually by using plasma and photocatalysis. Additionally, this review compares different designs of cold plasma reactors combination with heterogeneous catalysis with special attention on synergistic and antagonistic effects of using plasma and photocatalysis processes at the laboratory, pilot, and industrial scales. Therefore, the elements discussed in this review stick well to the first theme on pollution prevention of the special issue concerning pollution prevention and the application of clean technologies to promote a circular (bio) economy.

Sustainable carbonaceous biochar adsorbents derived from agro-wastes and invasive plants for cation dye adsorption from water.

This study investigated methyl orange (MO) dye adsorption using three biochars produced from agro-waste and invasive plants; the latter consisted of wattle bark (BA), mimosa (BM), and coffee husks (BC). BC had the lowest specific surface area (2.62 m2/g) compared to BA (393.15 m2/g) and BM (285.53 m2/g). The adsorption efficiency of MO was stable at pH 2-7 (95%-96%), whilst it had reduced stability at pH 7-12. Between 0 and 30 min, MO adsorption efficiency was >82%, and at 120 min, representative adsorption equilibrium had occurred. The maximum adsorption capacity of the biochars was 12.3 mg/g. The underlying adsorption mechanisms of the three biochars were governed by electrostatic adsorption and pore diffusion. There was an abundance of active sites for adsorption in BA and BM, while chemical adsorption appeared to be more vital for BC, as it contained more functional groups on its surface. The highest MO adsorption efficiency occurred with BM. BC was not recommended for MO removal, as it was observed to stain the water when a dose exceeding 5.0 g/L was utilized.