Preparation and characterization of multifunctional sponge-gourd fibers (Luffa cylindrica)/ hydroxyapatite composites for removal of lead and methylene blue

Abstract

Cellulose, oxidized-fibers, and oxidized-nanocellulose were isolated from sponge-gourd fibers (Luffa cylindrica). Isolated materials showed different morphology (shape and size), chemical, crystalline properties, and removal efficiency against methylene blue (MB) and lead ions (Pb2+). The cellulosic materials showed high efficiency in removing MB more than Pb2+. So, different luffa forms/hydroxyapatite (HAp) composites were prepared and used as adsorbents for removal of both MB and Pb2+ from aqueous solutions. The effect of sorbent type, contact time, and initial MB and Pb2+ concentrations were studied. HAp was successfully synthesized on the surface of luffa with an average length of 40–56 nm and width of 14–19 nm. Kinetic and adsorption studies of MB and Pb2+ ions were well fitted with the pseudo-second-order model and Langmuir model. The maximum adsorption capacity of MB was 25.2 mg/g, 30.8 mg/g, and 36.2 mg/g for oxidized-fibers/HAp, oxidized-fibers, and cellulose, respectively, and for Pb2+ was 625 mg/g, 714 mg/g, and 714.5 mg/g for oxidized-fibers/HAp, oxidized-nanocellulose/HAp, and cellulose/HAp, respectively. Also, more than 85% of MB (25 mg/L) and 95% of lead (500 mg/L) were removed within the first 5 min. Oxidize-fibers/HAp composite showed effective adsorption with both MB and Pb2+ in a very short time.

Experimental investigation on the effect of fiber volume fraction of sponge gourd outer skin fiber reinforced epoxy composites

“…[ 21 ] Moreover, L. cylindrica has toxic less and cost‐effective adsorbents which has a significant effective in removal of Pb 2+ ions than methylene blue compared to luffa without hydroxyapatite. [ 22 ] The nanoparticle of erminalia chebula particulate‐filled with Coccinia grandis/epoxy composite has low water absorption rate and higher mechanical properties and produced higher chair yield at 547°C. [ 23 ]…”