Methylene Blue and Iron (II) Adsorption onto Raphia Hookeri Seed: A Comparative Equilibrium Isotherm Study

Abstract

In this study, activated carbon prepared from Raphia hookeri seed was employed as an adsorbent to take up methylene blue (an organic ion-in-solution) and iron (II), a metal ion-in-solution. The biosorbent was prepared using chemical activation using sodium hydroxide (NaOH) as an impregnating agent. Calibration was performed with a focus on the change in the adsorbate concentration. The equilibrium isotherms study was conducted by considering a range of sorbate concentrations, to determine the optimal conditions for the adsorption systems. The same sorbate volume (10 ml), and the same dosage (0.3g) of biosorbent were used for both adsorption processes. Linear analysis was used to compare the best-fitting isotherms. Langmuir, Freundlich, and Dubinin-Radushkevich models were tested. The highest coefficient of determination values (R2) for both iron (II) and Methylene blue was obtained from the Langmuir isotherm as 0.9266 and 0.9572, respectively, compared to values from the other isotherms tested – indicative of Langmuir isotherm’s superior fit. Estimated values of ‘separation factor’, KR, for Methylene blue (0.29457), however, was lower than that of iron (II) (0.42141) - an indication that the sorbent treats methylene blue better than iron (II), though both processes are feasible.

Blighia sapida Waste Biochar in Batch and Fixed-Bed Adsorption of Chloroquine Phosphate: Efficacy Validation Using Artificial Neural Networks

“…The maximum monolayer adsorption capacity of the Langmuir isotherm was found to be 99.01 mg/g. The value of n for the Freundlich model was obtained to be greater than 1, which validated the favorability of the adsorption process . The correlation coefficient ( R 2 = 0.9729) of the Freundlich model was found to be larger than that of Langmuir (0.9358).…”

“…The value of n for the Freundlich model was obtained to be greater than 1, which validated the favorability of the adsorption process. 52 The correlation coefficient ( R 2 = 0.9729) of the Freundlich model was found to be larger than that of Langmuir (0.9358). This implied that multilayer adsorption occurred in the BSSP-CQP system.…”

The efficiency of Raphia hookeri adsorbent in indigo carmine dye removal: Economy depth via chemometrics

“…This is an indication that the density of the adsorbent’s precursor is moderately small. Hence, the prepared adsorbent (RHPW) will be a promising adsorbent for adsorption [ 25 , 39 ].…”

“…Raphia palm grows naturally and abundantly in the south-southern states of Nigeria, and hence a suitable adsorbant precursor considering its wide availability and low-cost [ 38 ]. Although Raphia hookeri wastes (RHPW) has been utilized in the uptake of a few pollutant which include dyes such as Methylene blue [ 39 ], Erythrosine B [ 38 ], acetaminophen [ 19 ], Rhodamine B [ 29 ], and heavy metals such as Copper [ 28 ], Cadmium [ 40 ], Lead [ 41 ]. To our extent of awareness, no previous report exists for the use of RHPW in the uptake of ICD (a dye with great applications).…”