Evaluation of zinc adsorption using cassava peels (Manihot esculenta) modified with citric acid

Abstract

The adsorption of zinc from aqueous solutions on cassava peels (Manihot esculenta) modified with citric acid was studied. Cassava peels were modified with citric acid according to a fractional experimental design with central point, which had as independent variables: mixing time, drying time, reaction time, mixing temperature, reaction temperature, and biomass/acid ratio. In order to determine the best conditions to perform the chemical modification, removal experiments were carried out with the samples specified in the experimental design. Under these conditions, kinetic experiments were developed resulting in fast adsorption of zinc with equilibrium times within 20-30 minutes range, and adsorption capacities of 3.042 mg/g and 4.904 mg/g for zinc solutions of 30 and 50 mg/L, respectively. At these initial concentrations of zinc, the experimental data fit the kinetic pseudo-second order model.

Chemical Modification of Agro-Industrial Waste-Based Bioadsorbents for Enhanced Removal of Zn(II) Ions from Aqueous Solutions

“…As shown in Figure 2 , banana, granadilla, and orange bio-adsorbent spectra show bands between 3600–3000 cm −1 , which correspond to the hydroxyl group (OH – ). These bands are due to the stretching of the OH – bonds of cellulose, hemicellulose, lignin, citric acid, and water from the residual moisture of the peels [ 79 ]. The bands located between 3000 and 2800 cm −1 belong to the stretching of C–H groups.…”

A Review on Cassava Residues as Adsorbents for Removal of Organic and Inorganic Contaminants in Water and Wastewater

“…In the literature, various parts of cassava are reported to be adsorbents used in the removal of heavy metals, for example, zinc ( [10][11][12][13]), copper ([11, 13-21]), lead ( [20][21][22][23][24][25][26][27][28]), cobalt ( [29,30]), vanadium [30], chromium ([13, 17, 30, 31]), and cadmium ( [12,15,[32][33][34]), dyes such as rhodamine B [35], direct red [36], methylene blue ( [36][37][38][39][40]), methyl orange [40], and reactive dyes [41], antibiotics ([22, 42-44]), phosphorous [45], biodiesel purifcation [46], organic pollutants from industrial efuents ( [29,47,48]), and free fatty acid [49]. In addition, ZnO nanoparticles synthesized from cassava starch are used as adsorbents [50].…”

Sequestration of Lead Ion in Aqueous Solution onto Chemically Pretreated Pycnanthus angolensis Seed Husk: Implications for Wastewater Treatment

“…The peaks between 2923 and 2852 cm −1 range correspond to the stretching vibration of the C−H aliphatic. The broad peak at 3433 cm −1 correlates with the stretching vibration of the OHand N−H groups of the cellulose, hemicellulose, and lignin materials[61]. The oxygen-rich functional groups (−OH), (−C=O), and (−COOH) that account for the binding of the metal ion with the adsorbent are rich in both cellulosic and hemicellulose materials[62].…”