Adsorption of Methylene Blue by an Efficient Activated Carbon Prepared from Citrullus lanatus Rind: Kinetic, Isotherm, Thermodynamic, and Mechanism Analysis

Abstract

By using the activated carbon obtained from Citrullus lanatus rind by zinc chloride activation, methylene blue (MB) removal from aqueous solutions was studied, and the adsorption mechanism was solved through Weber-Morris intraparticle diffusion model, Bangham model, Boyd model, Fourier transform infrared spectra, and scanning electron microscopy. The effects of adsorption parameters (adsorbent concentration, temperature, initial dye concentration, and pH) were investigated. The equilibrium data of MB adsorption were described by applying the Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherm models. The obtained results from adsorption isotherms indicated that Langmuir model is the bestfitted model with the maximum adsorption capacities of 231.48, 243.90, 244.50, and 259.74 mg/g at 25, 35, 45, and 55°C, respectively. The analysis of the kinetic data by pseudo-first-order, pseudo-second-order, and Elovich models displayed that MB adsorption followed pseudo-second-order model. Also, the date obtained from intraparticle diffusion model, Bangham model, and Boyd model presented that intraparticle diffusion, pore diffusion, and film diffusion played significant role in MB adsorption. The thermodynamic studies demonstrated that MB adsorption onto the activated carbon obtained from C. lanatus rind was physical, spontaneous, feasible, and endothermic. Thus, the activated carbon prepared from C. lanatus rind has been an efficient adsorbent for MB removal from an aqueous solution.

Entrapment of distilled palmarosa (cymbopogon martinii) wastes in alginate beads for adsorptive removal of methylene blue from aqueous solution

“…The pseudo-second-order model expresses that the interactions between the adsorbent and adsorbate are via electron sharing and transfer between the two species and thus entirely controlled by chemisorptions process whereas, the pseudo-first-order model is better suited to physical adsorption processes. Similar results were reported for MB adsorption by various adsorbents, such as Citrulluslanatus rind activated carbon, alginate-based nanocomposite, and biochar [41][42][43].…”

“…Though the value of 1/n are less than 1 at all the temperature studied, indicating a favorable adsorption process, however, the R 2 values were lower than the Langmuir counterpart and were in the range of 0.881 to 0.977. Increase in k F values of MB adsorption on to PDWAB from 1.01 to 2.24 mg/g with increase in temperature from 298 to 328 K, reaffirms the positive effect of temperature on MB adsorption onto PDWAB, similarly as in the study by Sheha and Metwally [50] and € Uner et al [41].…”

“…Increase in k F values of MB adsorption on to PDWAB from 1.01 to 2.24 mg/g with increase in temperature from 298 to 328 K, reaffirms the positive effect of temperature on MB adsorption onto PDWAB, similarly as in the study by Sheha and Metwally and Üner et al . .…”

Utilization of Euryale ferox Salisbury seed shell for removal of basic fuchsin dye from water: equilibrium and kinetics investigation

“…18 Another decomposition at 330 C to 500 C corresponds to residual lignin, cellulose, pectin and hemicelluloses in the adsorption study of methylene blue by Citrullus lanatus rind. 19 Around 5% remnants aer 500 C accounts for the ash content of the biomaterial. The absence of noteworthy changes above 600 C indicates the optimum carbonization temperature to be around 600 C. From the DTG curve, the primary decomposition temperatures for the E. ferox were found to be 67, 295, 325 and 500 C respectively.…”

Adsorption of bovine serum albumin onto activated carbon prepared from Elaeagnus stone

“…Adsorption method is widely used in the removals of contaminants from aqueous solutions [12][13][14][15][16][17]. The adsorption process in which activated carbons are used is operative, but its applications are limited due to the high production costs of activated carbons [18].…”