Adsorption of heavy metal ions onto chitosan grafted cocoa husk char

Abstract

The use of chitosan-grafted cocoa husk char (CCH) and unmodified cocoa husk char (CH) as adsorbents for the removal of Cr 6+ and Pb 2+ were studied. The adsorption efficiencies were compared with that of the commercial activated carbon (GAC F-300). Energy Dispersive X-ray spectroscopy (EDS) was used to determine the elemental compositions of the adsorbents while Scanning Electron Microscope (SEM) was used for the surface texture and morphological characteristics of the cocoa husk. The study optimised metal ion concentration, adsorbent dosage, agitation time and adsorbent particle size for the removal of the metals from simulated wastewater using Atomic Absorption spectroscopy (AAS) and removal efficiencies were calculated. Langmuir and Freundlich models were employed to study the adsorption pattern. The equilibrium experimental data results of Pb 2+ fitted well to Langmuir and Freundlich the two adsorption isotherms. The coefficient of correlation (R 2) for both models falls within 0<R 2 <1. The experimental data obtained from the sorption of Cr 6+ by the adsorbents, except CH, fitted Langmuir model than Freundlich model. The Langmuir isotherm fits the experimental data than Freundlich isotherm for Cr 6+ sorption by the CCH modified cocoa husk and the activated carbon except the unmodified cocoa husk. The study concluded that cocoa husk, an agricultural waste material, have potential as an adsorbent to remove toxic heavy metal like chromium and lead from industrial waste water. Modification of this waste with chitosan also enhances its performance in the removal of the metals.

Preparation of methacrylamide-functionalized crosslinked chitosan by free radical polymerization for the removal of lead ions

“…It can be concluded that crosslinked chitosan-g-PMAm exhibits good adsorption capacity and can be workable for new potential adsorption systems. Polyaniline grafted crosslinked chitosan 114 (Igberase & Osifo, 2015) Iodate doped chitosan composite 22.2 (Gedam & Dongre, 2015) Chitosan modified cocoa husk carbon 263.2 (Aderonke et al, 2014) Halomonas BVR1 immobilized in chitosan 24.2 (Manasi, Rajesh, & Rajesh 2015) Bromine pretreated chitosan 1.8 (Dongre, Thakur, Ghugal, & Meshram, 2012) Crosslinked chitosan-clay beads 7.9 (Tirtom, Dincer, Becerik, Aydemir, & Çelik , 2012) Chitosan crosslinked with citric acidglutaraldehyde 103.6 (Suc & Ly, 2013) Crosslinked chitosan-g-PMAm 250…”

Removal of Cu(II) using three low-cost adsorbents and prediction of adsorption using artificial neural networks

“…Precipitation is the most widely used method for the removal of copper as its hydroxide or sulfide. However, major problem with precipitation is the disposal of precipitated cupric hydroxide (Aderonke et al 2014). These existing methods that are generally expensive (Ferraz et al 2015) lead to incomplete metal removal, high energy consumption and generation of toxic sludge.…”

Extraction and Characterization of Chitosan from Crab Shells: Kinetic and Thermodynamic Studies of Arsenic and Copper Adsorption from Electroplating Wastewater

“…From Table-3, the increase in the values of the Freundlich constant (K f ), as adsorption capacities of chitosan for the metal ions, is in the order of Cu>As. The higher adsorption capacity of chitosan for Cu as compared to As may be attributed to its greater adsorption affinity toward chitosan [53].…”