Chromium (III) adsorption from the phosphoric acid medium using DETA grafted Merrifield resin.

To selectively remove Cr (III) from synthetic phosphoric acid solution, a chelating ion exchanger was developed through Merrifield resin (MHL) functionalization with diethylenetriamine (DETA). The functional moieties of the grafted Merrifield resin were characterized and confirmed by means of Fourier-transform infrared spectroscopy. The morphological changes before and right after functionalization were visualized with Scanning electron microscopy and enhanced amine content was confirmed via energy dispersive X-ray. To assess the effectiveness of the MHL-DETA in the extraction of Cr (III) from a synthetic phosphoric acid solution, batch shaking adsorption tests were conducted through optimizing different factors such as contact time, metal ion concentration and temperature. According to our findings, higher adsorption was achieved when increasing contact time and decreasing metal ion concentration, while temperature variation doesn't affect much the process. The higher sorption yield was found to be 95.88% attained within 120 min at room temperature without varying the solution's pH. Under optimum conditions (120 min, 25 °C and 300 mg. L-1), the total sorption capacity was reported to be 38.35 mg. g-1. The system's adsorption behavior was found to be consistent with the Langmuir isotherm and the pseudo second-order model accurately described the kinetic data. In this view, Merrifield resin functionalized with DETA could be used as a promising adsorbent material for Cr (III) adsorption from synthetic phosphoric acid medium.

Photoluminescent biocomposite films of chitosan based on styrylbenzothiazolium-g-cellulose nanocrystal for anti-counterfeiting applications.

In the present investigation, novel photoluminescent and transparent biocomposite films based on chitosan reinforced with styrylbenzothiazolium-g-cellulose nanocrystal for anti-counterfeiting applications were successfully prepared by casting solvent. Three novel styrylbenzothiazolium derivatives were synthesized by Knoevenagel condensation and characterized by FTIR, 1H, 13C NMR and photoluminescence analysis. These photochromic compounds have been used to functionalize cellulose nanocrystal and the resulting fluorescent photonic materials were characterized by FTIR, 13C-CP/MAS NMR as well as photoluminescent analysis to confirm the successful grafting. It can be concluded that the addition of 5 wt% of fluorescent modified CNC to chitosan matrix increase the photoluminescent properties as well as improved the mechanical properties of the Cs/CNC-dye biocomposite films. These photoluminescent biocomposite film hold promising applicative value in anti-counterfeiting material in large-scale.

Bioformulation of Microbial Fertilizer Based on Clay and Alginate Encapsulation.

This study aims to develop new formulations for microbial fertilizers Pseudomonas fluorescens Ms-01 (Pf) and Azosprillum brasilense DSM1690 (Ab) using two kinds of clay minerals. The studied formulations were prepared as hybrid materials based on halloysite and alginate [Ha-Ag] or montmorillonite and alginate polymers [Mt-Ag] and were applied to the bacterial strains to develop low cost, efficient, and slow-release capsules. Their efficiency was evaluated in comparison with alginate [Ag] as the control. The produced capsules were spherical in shape and were chemically and physically characterized and further analyzed for their swelling ratios, soil biodegradability, release kinetics of microbial cells, and their survival stability over 3 months of storage under different conditions (room temperature vs 4 °C). The effect of the capsules on the growth of wheat plants was also investigated. Results showed that both formulations were able to preserve bacterial survival which reached 14.8 log CFU g-1 after 3 months storage in the halloysite formulation. The swelling ratios were ranged between 61.5 ± 1.35% and 36.5 ± 5% for the montmorillonite and the halloysite formulations, respectively. The release kinetics revealed the slow-release capacity of the capsules mainly with the halloysite formulation which significantly released bacterial cells after 15 days of incubation in saline water (15.24 log CFU mL-1). The application of the capsules to wheat plants significantly increased root and shoot biomasses and nitrogen content in the roots. In conclusion, halloysite minerals seem to be more adapted as additive to alginate in microbial encapsulation.