Rubber seeds (Hevea brasiliensis): an adsorbent for adsorption of Congo red from aqueous solution

Abstract

A B S T R A C TThis study aims to investigate the use of rubber (Hevea brasiliensis) seeds, a solid agricultural waste, as a novel adsorbent for the adsorption of Congo red (CR) from aqueous solution in batch mode. Experiments were carried out as a function of contact time, dye concentration, adsorbent dosage, pH, and temperature. Langmuir, Freundlich, and Sips adsorption isotherm models were applied to describe isotherm parameters. The results showed that equilibrium contact time was 90 min. The experimental results indicate that, the percentage of dye adsorption increases with an increase in the adsorbent dosages and temperature. The CR adsorption percentage decreased with increasing dye concentration and pH solution from 3 to 12. Thermodynamic parameters data indicated that the CR adsorption process was nonspontaneous and endothermic under the experimental conditions, with the Gibbs free energy (ΔG˚) in the range of 9.13-8.12 kJ/mol, enthalpy (ΔH˚) and entropy (ΔS˚) of 14.15 kJ/mol and 16.85 J/mol, respectively. The Langmuir isotherm model fit the equilibrium data better than both the Freundlich and Sips isotherm models, with adsorption capacity 9.82 mg/g. The kinetic data for adsorption processes were described by pseudo-second-order model with a rate constant in the range of 0.043-0.156 g mg/g min −1 . The rubber seeds investigated in this study showed a high potential use for the adsorption of CR from aqueous solution.

Application of Activated Carbon Adsorbents Prepared from Prickly Pear Fruit Seeds and a Conductive Polymer Matrix to Remove Congo Red from Aqueous Solutions

“…Polymers induced the generation of adsorption active sites for CR, which in turn increased removal capacity. On the other hand, a comparison of relative adsorption using different adsorbent materials based on the literature is summarized in Table 4 [55][56][57][58][59][60][61][62][63][64][65][66][67][68][69][70][71].…”

Optimizing the Methylene Blue Removal from Aqueous Solution Using Pomelo Peel Based Biochar Assisted by RSM and ANN-PSO

“…0.1 mol H 2 SO 4 was found suitable for regeneration and MB removal decreased up to 23.6% after three cycles. Zulfikar et al [12] exhibited the potential use of natural rubber seeds to remove MB from aqueous solution. NRS was pretreated using epichlorohydrin and concentrated H 2 SO 4 in various impregnation ratios to produce modified NRS called NRSEA.…”

“…NRS was pretreated using epichlorohydrin and concentrated H 2 SO 4 in various impregnation ratios to produce modified NRS called NRSEA. The results of MB adsorption ability test onto NRSEA showed that the adsorption capacity increased with increasing pH (within the pH range of [7][8][9][10][11][12] and decreased afterwards, the optimum initial MB concentration reached at 800 mg/L, and the equilibrium state was achieved at 120 min of contact time. Enhanced methylene blue removal from aqueous solution using modified rubber seed (Hevea brasiliensis).…”

Modification of Carbon Paste Electrode with Molecularly Imprinted Poly(Gluthamic Acid) for Determination of Rhodamine: A Preliminary Study

“…Polymer films or membranes can be modified by molding from target molecules which are often called molecularly imprinted polymers (MIPs). Some researchers have succeeded in developing MIPs and other membranes for the purposes of separation [18], [19], [20].…”