The paper reports experimental research regarding the mechanical characteristics of concrete reinforced with natural cellulosic fibers like jute, sisal, sugarcane, and coconut. Each type of natural fiber, with an average of 30 mm length, was mixed with a concrete matrix in varying proportions of 0.5% to 3% mass. The tensile and compressive strength of the developed concrete samples with cellulosic fiber reinforcement gradually increased with the increasing proportion of natural cellulosic fibers up to 2%. A further increase in fiber loading fraction results in deterioration of the mechanical properties. By using jute and sisal fiber reinforcement, about 11.6% to 20.2% improvement in tensile and compressive strength, respectively, was observed compared to plain concrete, just by adding 2% of fibers in the concrete mix. Bending strength increased for the natural fiber-based concrete with up to 1.5% fiber loading. However, a decrease in bending strength was observed beyond 1.5% loading due to cracks at fiber−concrete interface. The impact performance showed gradual improvement with natural fiber loading of up to 2%. The water absorption capacity of natural cellulosic fiber reinforced concrete decreased substantially; however, it increased with the loading percent of fibers. The natural fiber reinforced concrete can be commercially used for interior or exterior pavements and flooring slabs as a sustainable construction material for the future.

Organic-inorganic hybrid polymers have been demonstrated to be an efficient technique for the adsorption of pollutants present in water. Silica gel adsorbent has been applied in this field due to promising characters, such as thermally stable, reusability and high metal ion adsorption capacities. Here, silica gel supported acrylonitrile functional group (silica-APTS-DPN) was reacted with hydroxylamine to yield silica gel supported amidoxime ligand (SBA). All the functionalized silica gel adsorbents were characterized by FTIR. In terms of metal ions adsorption, SBA revealed good absorption capacities towards both copper (Cu2+) (172 mg g-1) and iron (Fe3+) (168 mg g-1) ions at pH 6 and followed the order of Cu2+ > Fe3+. Increased pH condition was beneficial for both metal ions adsorption. The adsorption kinetics of both ions followed the pseudo-first-order model within 0-60 min of adsorption time. Langmuir and Freundlich isotherm models were both applied to study the adsorption behaviour, Freundlich isotherm model (R2 > 0.99) proved to be a better fit, which propose that multilayer adsorption occurred on the silica gel grafted with amidoxime ligand. Finally, this study proved that the silica gel supported amidoxime ligand was successfully applied as an absorbent for the removal of both copper and iron from aqueous media.