Activated Plantain Peel Biochar As Adsorbent For Removal of Zinc(II) Ions From Aqueous Solution: Equilibrium and Kinetics Studies.

Abstract

Plantain peel biomass was carbonized, activated, and characterized using BET surface area and XRD. The XRD diffraction indicated crystalline structure with crystallite size of 14.56 nm evaluated through Debye-Scherrer equation. The pore size (cc/g) and pore surface area (m 2 /g) of the biochar was 8.79 and 16.69 respectively from BET surface area. Various parametric properties such as effect of initial metal ion concentration, pH, and contact time were studied in a batch reaction process. Adsorption of zinc from aqueous solution decreased with an increase of pH and initial concentration. Equilibrium modeling studies suggested that the data fitted mainly to the Langmuir isotherm. Adsorption kinetic data tested using various kinetic models fitted the Bangham's pore diffusion model implicating pore diffusion as the main rate limiting step. The sorption studies indicated the potential of plantain peel biochar as an effective, efficient and low cost adsorbent for remediating zinc (II) ions contaminated environment.

Hydrothermal Synthesis of Fluorescent Schiff Base Functionalized Carbon Dot Composite for The Removal Of Cd(II) Ions From Aqueous Solution: Equilibrium and Kinetic Studies.

“…Reaching equilibrium for the functionalized nanosized adsorbent was rapid and remained fairly constant, implying the presence of uniform adsorption site which upon saturation by the adsorbate through hydrogen bonding and dipole-dipole interactions was filled up without more spaces or binding sites to occupy (22)(23). The maximum adsorption indicating saturation point was observed at equilibrium and for a nano-based material it has been observed in similar study to lie at the same range (23-25).…”

“…The Freundlich adsorption strength (n) which indicates the degree of nonlinearity between the adsorption process and concentration of solution was 0.229. Consequently, if n=1, adsorption process was linear, if n < 1, adsorption process was chemisorption while if n > 1, adsorption process was physisorption (22). Based on the value of n, the adsorption process is basically physisorption.…”

“…The value of RL determines the nature of Langmuir isotherms and generally when RL=0, the isotherm is irreversible, if RL > 1, then it is unfavorable, if RL =1, then it is linear but if 0 < RL < 1 then it is favorable (22). Evaluating RL from the experimental data revealed that the values are in the range of 0.009 to 0.405 indicating a favorable adsorption process of Cd(II) ion on the functionalized carbon dot.…”

“…The implication is that monolayer coverage of the finite number of adsorption sites on the functionalized carbon dot is prominent with uniform and equivalent adsorption sites. Interaction between the adsorbed molecules is impaired and the adsorption of Cd(II) ions onto the functionalized carbon dot is inconsequential of the occupied nearby sites (1,22,26). The implication is that at the point of saturation or maximum adsorption at the adsorptive site of the functionalized carbon dot, further adsorption is quenched or hindered.…”

Nonlinear Fitting for Estimation of Adsorption Equilibrium, Kinetic and Thermodynamic Parameters of Methylene Blue onto Activated Carbon

“…Adsorption is considered one of the best techniques used to remove dye from a solution due to its high efficiency, effectiveness, and low cost (15). In this regard, well-known adsorbents, such as activated carbon (16), biomass (17) zeolite, clay materials (18), and polymers (19), are used to remove the contaminating dyes. The adsorption is classified based on the adsorbate-adsorbent interaction and the heat associated with the process.…”