Mesoporous Activated Carbon from Leaf Sheath Date Palm Fibers by Microwave-Assisted Phosphoric Acid Activation for Efficient Dye Adsorption

Abstract

Remazol Brilliant Blue R (RBBR) is a common dye used in the industry, and its presence in wastewater and discharge into the environment can create a serious concern for the ecosystem and human health. Activated carbon produced from crop residues has emerged as a promising technique for removing contaminants from wastewater. In this study, leaf sheath date palm fiber-based activated carbon (LSDAC) was synthesized via phosphoric acid, H 3 PO 4 , treatment, followed by a microwaveinduced carbonization process. The produced LSDAC was found to have a BET surface area of 604.61 m 2 /g, a Langmuir surface area of 922.05 m 2 /g, a total pore volume of 0.35 cm 3 /g, and an average pore size of 2.75 nm. The highest removal of RBBR was achieved at a solution pH of 3 (92.56 mg/g) and a solution temperature of 50 °C (90.37 mg/g). Adsorption of RBBR onto LSDAC followed the Langmuir isotherm model with a maximum monolayer capacity, Q m , of 243.43 mg/g, whereas in terms of kinetics, this adsorption system was best described by the pseudo-first-order (PFO) model. The calculated thermodynamic parameters ΔH°, ΔS°, ΔG°, and Arrhenius activation energy, E a , were 4.71 kJ/mol, 0.10 kJ/mol•K, −26.25 kJ/mol, and 5.88 kJ/mol, respectively, indicating that the adsorption of RBBR onto LSDAC was endothermic in nature, exhibited increased randomness at the solid−liquid interface, and was spontaneous and controlled by physisorption.

Modelling the Kinetics of Tartrazine Sorption by the Rhizopus arrhizus Biomass

“…Because of this, the values that were calculated for the parameters of the adsorption kinetic models, particularly the rate constants that are significant, cannot be accepted [43]. When compared to activated carbon or biochar, raw untreated biosorbent surface rarely exhibits extensive pores, which results in very low pore diffusion activities during adsorption [44][45][46]. Additionally, since the majority of experiments involve rapid stirring of the reaction, this reduces film diffusion to an absolute minimum.…”

Adsorption of Pb2+ by Activated Carbon Produced by Microwave-Assisted K2CO3 Activation of Date Palm Leaf Sheath Fibres

“…For instance, one date palm tree can produce up to 40 kg of waste per year, including dried leaves, sheaths, spathes and petioles [41]. AC derived from date palm leaf sheath fibres has been shown to effectively remove dye from aqueous solutions [42], and its efficiency for adsorbing heavy metals deserves further investigation. The utilisation of date palm leaf sheath fibres for the production of AC can reduce the amount of generated date palm waste in addition to saving the environment by adsorbing Pb 2+ pollutants from aqueous solutions.…”

Adsorption of Pb2+ by Activated Carbon Produced by Microwave Assisted K2CO3 Activation of Leaf Sheath Fibre of Date Palm

“…Beside production of edible fruits, the date palm tree produces large amounts of agricultural wastes; for instance one date palm tree can produce up to 40 kg of waste per year, ranging from dried leaves, sheaths, spathes and petioles (Rambabu et al, 2021). Conversion of leaf sheath date palm fibers to AC was effective for removing dye from aqueous solution (Alharbi et al, 2022b), and its efficiency for adsorbing heavy metal deserves further investigation. Utilization of leaf sheath date palm fibers for producing AC can be a good approach to reduce the amount of generated date palm waste in addition to saving the environment by adsorbing Pb 2+ pollutant from aqueous solution.…”