Articles

The study focused on the solvent extraction of Cr(III) from sulfate media using Cyanex 302 (bis (2,4,4-trimethylpentyl) monothio-phosphinic acid). Various parameters were systematically evaluated, including phase contact time, initial pH, metal ion concentration, extractant concentration, sulfate ion concentration, temperature, and the type of diluent. Equilibrium was reached within 30 minutes, with the highest extraction efficiency occurring at pH 5.0. Adding more Cyanex 302 improved the extraction efficiency. The study showed that each Cr(III) ion paired with a single dimeric extractant molecule. The presence of sulfate ions was found to hinder extraction by forming non-extractable chromium complexes. The extraction process was endothermic, as indicated by positive enthalpy changes. Among the diluents tested, toluene showed the highest extraction efficiency; however, kerosene was chosen for practical reasons. The maximum loading capacity of Cyanex 302 for Cr(III) was determined to be 2.742 g per 100 g of the extractant. Research found that sulfuric acid was good for stripping, but HCl and HNO3 did not work in the conditions tested. Cyanex 302 had a medium level of extraction efficiency compared to other extractants. These results suggest that Cyanex 302 holds promise for industrial applications in Cr recovery processes, although further optimization may be required to enhance its effectiveness.

Rice husk is an abundant natural resource that contains about 33% cellulose. This study focused on the extraction and develop of carboxymethyl cellulose (CMC) from rice husks and its utilization in developing CMC-polyvinylpyrrolidone (PVP) blended hydrogel (HGEL) membranes with varying CMC:PVP ratios (80:20, 60:40, and 50:50 w/w). The controlled release of pharmaceuticals and targeted drug administration depend on pH-responsive drug delivery systems. An innovative pH-sensitive, biodegradable, and antibacterial hydrogel was synthesized through blending and solution casting method, using glutaraldehyde as a crosslinking agent. Structural and physicochemical characterization confirmed successful hydrogel formation: FTIR validated crosslinked network development, TGA demonstrated enhanced thermal stability, and SEM revealed uniform and interconnected morphologies. Swelling studies showed that swelling capacity could be precisely tuned by altering the CMC/PVP composition, with higher pH conditions markedly increasing swelling, confirming the pH-responsive behavior of the hydrogels. The drug (salicylic acid) release profiles from gel membrane were conducted into two separate release media (pH 1.4, and pH 7.4), with samples evaluated spectrophotometric analysis at 294 nm wavelength using a UV-Vis spectrophotometer, showed a consistent and controlled release profile. Biodegradability tests in soil revealed that the hydrogel sample degraded gradually up to 72.65% within 15 days. Moreover, upon testing on bacteria Staphylococcus aureus (G+) & Escherichia coli (G-) bacterium, the sample (50:50) gave 11 mm of inhibition zone diameter which confirmed that the synthesized hydrogel can be used for wound dressing and other biomedical applications. Altogether hydrogels underlined as a prospective category of eco-friendly and tunable biomaterials for future healthcare innovations.

As Bangladesh is enriched with fish resources of fresh water, few studies have been conducted to reveal the nutritional value of fish oils. In our present work, we aimed to study the composition of extracted lipids from Colisa fasciatus to explore the medicinal value of this fish which can be used as a precursor for nutraceuticals also. The lipid was extracted from the fish using a solvent extraction method with chloroform and methanol. The qualitative parameters like acid value, peroxide value, saponification value and iodine value were calculated by chemical reaction methods. GCMS analysis was carried out to explore the composition of the extracted lipid. The antioxidant activity of the extracted lipid was carried out by DPPH radical scavenging and Iron reducing study. Thrombolytic activity of the sample was studied by weight difference method. Among 20 constituents hexadecanoic acid (42.808%) was present in the highest concentration. The other remarkable components are Methyl tetradecanoate, pentadecanoic acid, heptadecanoic acid and 9-Octadecanoic acid. Compared to butylated hydroxyl toluene (BHT) as standard, our extracted fish lipid showed 27.9% removal of DPPH. The thrombolytic property showed 7.07 % lysis of blood clots. The fatty acid composition of the extracted lipid supports physiological properties like antiaging and thrombolysis which can make a way to find a new array to use this fish lipid as a new nutritional supplement.

The extraction behaviour of vanadium (V) from nitric acid solutions was studied using technical grade D2EHPA in kerosene as an extractant. The effects of aqueous pH, the concentration of vanadium (V) and nitrate ion in the aqueous phase, and the concentration of D2EHPA in the organic phase were investigated. The extraction equilibration time was 30 min. Metal ion dependencies appeared non-ideal due to the non-constancy of the aqueous phase acidity and the equilibrium extractant concentration. Two types of extraction mechanisms originated from the study of pH dependency. The study conceded that the extraction of vanadium (V) occurred via ion exchange or chelation type of extraction when the pH (eq) <2.50. On the other hand, the solvated ion-pair extraction mechanism occurs when the pH (eq) was above 2.50. The extractant dependencies showed that vanadium (V) species were extracted by one molecule of D2EHPA. The salting-out effect was observed from the effect of nitrate ion concentration. The effect of various types of diluents on vanadium (V) extraction with technical grade D2EHPA was studied; kerosene appeared to be a suitable diluent. The temperature dependence data revealed that the system was exothermic with the &Delta;H value of -12.34 kJ/mol. The loading capacity was 6.11 g vanadium (V) per 100 g extractant. The H 2 SO 4 (0.5 mol/L) was the right stripping agent for the extracted species.