Preparation of cellulose gel extracted from rice straw and its application for metal ion removal from aqueous solutions.

Rice straw waste was used to extract natural cellulose fibers, which was then chemically converted to cellulose gel. Both extracted cellulose and modified cellulose (gel) were characterized using different techniques and used for biosorption of b+arium, manganese, cobalt, nickel, copper, zinc, and cadmium. Both celluloses' chemical compositions were investigated. The FT-IR, XRD, TEM, and SEM results all support the success of the proposed chemical modification. Because of the increase in pore size within the gel composition, the metal sorption capability of the final chelating material (gel) was greater than that of extracted cellulose. The experimental data were fit to the sorption isotherm models of Langmuir, Freundlich, and Temkin. This new modified biopolymer's behaviour suggested that it could be used as a promising sorbent for cation removal from polluted dye baths and waste water. Furthermore, this modified cellulose was prepared as cheap material extracted from the rise waste which helping in protection of the environment and it was confirm excellent behaviour in the removal heavy metals from their aqueous solution compared to the previous materials reported before.

One-pot fabrication of AgNPs, AuNPs and Ag-Au nano-alloy using cellulosic solid support for catalytic reduction application.

The current report provides a simple, green and inexpensive route for one-pot fabrication of AgNPs, AuNPs, and Ag-Au nano-alloy individually onto cellulosic solid support. Cellulosic solid support was naturally extracted from plant and then was used for deposition of nanoparticles. The manufacturing was carried out through redox reaction between metal ions and alcoholic groups of cellulose, resulting in production of metallic/bimetallic nanostructures. AuNPs was obtained in size of 26.1nm smaller than AgNPs (36.3nm). Controlling in size of bimetallic nanostructures was achieved by tuning the concentrations, mass ratios of nanometal precursors and their addition sequencing in reaction liquor. Immobilization of nanoparticles/bimetallic nanostructures was frequently speeded up the reduction reaction of p-nitro-aniline, however, bimetallic nanostructures exhibited much better catalytic reactivity, where, 87.2% from p-nitro-aniline was reduced to p-phenylene-di-amine only in 20min in the presence of Ag-Au bimetallic nano-alloy.

Equilibrium and kinetic models on the adsorption of Reactive Black 5 from aqueous solution using Eichhornia crassipes/chitosan composite.

New natural biopolymer composite was prepared using extracted cellulose from an environmentally problematic water hyacinth Eichhornia crassipes (EC). The extracted cellulose was functionalized by chitosan and TiO2 nanoparticles to form EC/Chitosan (EC/Cs) composite network. Surface characterization of EC/Cs natural biopolymer composite was examined by spectrum analysis FT-IR, specific surface area, micropore volume, pore width and SEM. Furthermore, the sorption experiments were carried out as a function of pH, various initial dye concentration and contact time. Experiment results showed that the EC/Cs composite have high ability to remove C.I. Reactive Black 5 from its dye-bath effluent. The equilibrium sorption evaluation of RB5 conformed and fitted well to Langmuir adsorption isotherm models and the maximum sorption capacity was 0.606 mg/g. The kinetic adsorption models followed pseudo-second order model and the dye intra-particle diffusion may suggesting a chemical reaction mechanism. Further, it was obvious from the investigation that this composite could be applied as a promising low cost adsorbent for anionic dye removal from aqueous solutions.

Nucleophilic addition of reactive dyes on amidoximated acrylic fabrics.

Seven reactive dyes judiciously selected based on chemical structures and fixation mechanisms were applied at 2% of of shade on amidoximated acrylic fabrics. Amidoximated acrylic fabric has been obtained by a viable amidoximation process. The dyeability of these fabrics was evaluated with respect to the dye exhaustion, fixation, and colour strength under different conditions of temperature and dyeing time. Nucleophilic addition type reactive dyes show higher colour data compared to nucleophilic substitution ones. FTIR studies further implicate the binding of reactive dyes on these fabrics. A tentative mechanism is proposed to rationalize the high fixation yield obtained using nucleophilic addition type reactive dyes. Also, the levelling and fastness properties were evaluated for all dyes used. Excellent to good fastness and levelling properties were obtained for all samples irrespective of the dye used. The result of investigation offers a new method for a viable reactive dyeing of amidoximated acrylic fabrics.