Activated Carbon from the Peelings of Cassava Tubers (Manihot esculenta) for the Removal of Nickel(II) Ions from Aqueous Solution

Abstract

Activated carbons were obtained from the peelings of cassava tubers (Manihot esculenta) by chemical activation using potassium hydroxide and phosphoric acid at impregnation ratios of 2 : 1 and 1 : 1, respectively, at 400°C for batch adsorption of nickel(II) ions from aqueous solution. Characterization of activated carbon samples was achieved via proximate analysis, Fourier-transform infrared spectroscopy, pH of zero-point charge, Boehm method, elemental analysis, scanning electron microscopy, and iodine number determination for each adsorbent. The effects of pH, contact time, initial adsorbate concentration, and adsorbent dose were studied at 27°C in order to optimize the conditions for maximum adsorption. Equilibrium was attained after 40 minutes of contact of both materials with activating solutions. Maximum adsorption capacities of 41.15 mg/g for ACPH, 47.39 mg/g for ACPA, 35.34 mg/g for NIC, and 34.48 mg/g for RM, respectively, were obtained at pH = 4. Equilibrium data showed that the Langmuir model best described the adsorption process with R2 closed to unity, indicative of monolayer adsorption on a homogeneous surface. Kinetic studies showed that the adsorption process is controlled by the pseudo-second-order model. These results show that activated carbon prepared from cassava peelings constitutes an effective low-cost material for the treatment of wastewater containing nickel(II) ions.

High-Efficiency Removal of Lead and Nickel Using Four Inert Dry Biomasses: Insights into the Adsorption Mechanisms

“…These results are coherent with the pH PZC values presented in Figure 1 , which are proportional to the acidic and basic functions. Similar results were presented for cassava tubes, with zero lactone groups [ 29 ]. For a biochar from oil palm fiber, it was reported values of 1.65, 0.2, and 0.15 mmol/g of carboxylic, phenolic, and lactone groups, respectively; this appearance of lactone groups decreases the quantity of the basic functions due to the carbonization phenomenon [ 48 ].…”

“…The utilization of biomass derived from agricultural residues as adsorbents has been extensively investigated due to its low cost, immediate availability, and high removal efficiency. Various bioadsorbents, including wood-derived biochar [ 24 ], plantain peels [ 22 , 25 ], Nitrile amidoximation of manna tree [ 26 ], Date palm biochar [ 27 ], rice husk [ 28 ], Carbon from cassava peels activated with KOH [ 29 ], Peat moss [ 30 ], potato husks [ 31 ], lemon [ 32 ], coffee pulp [ 33 ], and other residues, have been tested for the removal of these types of contaminants [ 34 , 35 ].…”

Porous Material Synthesis and Chromium (VI) Applications

“…It is seen that the C content of 58.77% of the SS increases in all carbonaceous porous materials. Zero load point (pH ZPC ) corresponds to a pH at which the surface charge of carbonaceous porous material is neutral [23]. Figure 11 shows the pH ZPC values of H3500 are given.…”

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

“…As a result, the rate of adsorption varies with the medium pH, not in a particular pattern. At low pH, the adsorption capacity for anionic molecules generally increases, whereas it decreases for cationic molecules [51]. Te electrostatic repulsion between the positively charged adsorbate and the adsorbent surface diminishes when the pH of the medium elevates, resulting in a rise in charge density of surfaces [52].…”