Removal of Cd(II) ions from aqueous solution using a cation exchanger derived from banana stem

Abstract

BACKGROUND: Environmental pollution and its abatement have attracted much attention for some time. The problem of removing pollutants from water and wastewater has grown along with rapid industrialization. Formaldehyde polymerized banana stem (FPBS) having sulphonic acid groups was investigated as an adsorbent for cadmium(II) removal from aqueous solutions.

Metals in aqueous solutions and real effluents: biosorption behavior of a hemp‐based felt

“…The performances of the hemp-based material toward pollutants present in real effluents can be explained by the presence of interactions between the metallic ions and the felt through physisorption (surface adsorption) and chemisorption (electrostatic interactions, precipitation) mechanisms 12,16,19,[23][24][25][26][27] . It was noted that, at the end of the biosorption process, a slight pH variation between 0.6 and 0.7 units was observed in each experiment, indicating a chemisorption mechanism.…”

Physicochemical characterization of raw and modified banana pseudostem fibers and their adsorption capacities for heavy metal Pb2+and Cd2+in water

“…Therefore, the initial stage involved the bulk transport of metal ions from the solution to the absorbent surface. However, with increasing contacting time, intra‐particular diffusion of metal ions into micro and mesopores on the absorbent surface might slow down the adsorption rate . On the other hand, the maximum absorbing amount for Pb 2+ (98.8680 mg/g) was significantly higher than Cd 2+ (66.2100 mg/g).…”

“…This implied that the metal ions absorbed at active sites could form a monolayer to block the fiber surface to absorb more ions [27]. Then, the specific sites for absorbing Pb 21 and Cd 21 became saturated as the metal ion concentration increased [10]. However, SEBF-CX exhibited significantly higher Pb 21 removal percentage of 93.85 and 80.09% at the concentrations of 500 and 1000 mg/L, respectively, compared with RBF and SEBF (below 36%) ( Table 3).…”

“…Thus, it is required to chemically modify to increase the adsorption capacity and stability at different conditions . Although the modification methods including hydrolysis, ionic liquefaction, steam explosion, and cation exchange have been widely reported to enhance the heavy metal or oil adsorption of banana pseudostem fibers, xanthogenation treatment could become an effective method in modifying fiber structure . However, the physicochemical properties, capacity of heavy metal adsorption, and relationship between the fiber structure and the capability of banana cellulose after xanthogenation have not been documented.…”

“…On the other hand, the xanthogenation method involves alkali‐treatment by NaOH, sulfonation by CS 2 , and substitution by magnesium salt to change the fiber cellulose structure . Since heavy metal ions, cadmium (Cd 2+ ) and lead (Pb 2+ ) are the ubiquitous environmental pollutants which are associated with the kidney damage, osteoporosis, and carcinogenic diseases as well as exhibiting higher toxicity than other trace metals even at low concentrations, they were selected to evaluate the heavy metal adsorption capacities of the raw and modified banana fiber in this study . This study evaluated the surface morphology, crystallinity, thermal property, structural characteristics of raw, steam explored, and xanthogenated banana fiber and the relationships of those parameters with heavy metal ion adsorption capacity.…”