Watermelon rinds as cost-efficient adsorbent for acridine orange: a response surface methodological approach

Abstract

In the current investigation, watermelon rinds (WMR) have been utilized as an eco-friendly and cost-efficient adsorbent for acridine orange (AO) from contaminated water samples. Adsorption of AO onto raw (RWM) and thermally treated rinds (TTWM250 and TTWM500) has been studied. The adsorption efficiency of the three adsorbents was evaluated by measuring the % removal (%R) of AO and the adsorption capacity (qe, mg/g). Dependent variables (%R and qe) were optimized as a function of four factors: pH, sorbent dosage (AD), the concentration of AO (DC), and contact time (ST). Box–Behnken (BB) design has been utilized to obtain the optimum adsorption conditions. Prepared adsorbents have been characterized using scanning electron microscopy (SEM), Fourier-transform infrared (FT-IR), and Raman spectroscopies. The surface area of RWM, TTWM250, and TTWM500, as per the Brunauer-Emmett-Teller (BET) analysis, was 2.66, 2.93, and 5.03 m2/g, respectively. Equilibrium investigations suggest that Freundlich model was perfectly fit for adsorption of AO onto TTWM500. Maximum adsorption capacity (qmax) of 69.44 mg/g was obtained using the Langmuir equation. Adsorption kinetics could be best described by the pseudo-second-order (PSO) model. The multi-cycle sorption-desorption study showed that TTWM500 could be regenerated with the adsorption efficiency being preserved up to 87% after six cycles.

Synthesis and Application of Cobalt Oxide (Co3O4)-Impregnated Olive Stones Biochar for the Removal of Rifampicin and Tigecycline: Multivariate Controlled Performance

“…A unique feature of BC is the surface structure which is controlled mainly by micropores-that facilitate removal of small molecules- followed by mesopores and macropores. The presence of meso- and macropores enables the diffusion of antibiotics into the adsorbent with faster transfer rates [ 4 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. Efforts to generate engineered BC which retains well-customized pore dimensions, and wider structural heterogeneity have been excreted.…”

Green Tea Waste as an Efficient Adsorbent for Methylene Blue: Structuring of a Novel Adsorbent Using Full Factorial Design

“…Approximately 5% of tanning wastes end up as effluents that are usually discarded into lakes, rivers, and ponds. Being colored and possessing variable chemical structures and different physicochemical properties, dyes represent a real burden on the ecosystem [3][4][5][6][7][8][9][10][11].…”

“…Reports show that MB produces toxic effects on the gastrointestinal system if ingested and an irritating effect on eyes in cases of contact [4][5][6]. Due to the associated health and environmental concerns, several remediation efforts have been reported to eliminate dyes from wastewater [3][4][5][6][7][8][9][10]. Among the reported techniques, adsorption is advantageous when compared to the other conventional approaches.…”

“…Among the reported techniques, adsorption is advantageous when compared to the other conventional approaches. Adsorption is a feasible, non-destructive technique with high removal efficiency, and it does not require prior treatment procedures and can be accomplished using eco-friendly materials with the lowest possible consumption of energy and resources [3][4][5][6][7][8][9][10][11][12][13].…”

“…Green adsorbents, a novel class of biosorbents, derived from agricultural/animal wastes are now commonly used for biosorption of contaminants from wastewater. Offering a compendium of advantages, including availability at low cost, potential for upcycling into value-added products for waste removal, a rich chemical composition with high surface area, and potential for modification, these wastes are progressively replacing the commercially available adsorbents [6][7][8][9][10][11][12][13].…”