Impact of Air Convection on H₃PO₄-Activated Biomass for Sequestration of Cu (II) and Cd (II) Ions

Abstract

Crushed, depitted peach stones were impregnated activated with 50% H followed by pyrolysis at 500 o C. Two activated carbons were produced, one under its own evolved gases during pyrolysis, and the second conducted with air flow throughout the carbonization stage. Physicochemical properties were investigated by several procedures; carbon yield, ash content, elemental chemical analysis, TG/DTG and FTIR spectra. Porosity characteristics were determined by the conventional N 2 adsorption at 77 K, and data analyzed to get the major texture parameters of surface area and pore volume. Highly developed activated carbons were obtained, essentially microporous, with slight effect of air on the porous structure. Oxygen was observed to be markedly incorporated in the carbon matrix during the air treatment process. Cation exchange capacity towards Cu (II) and Cd (II) was tested in batch single ion experimental mode, which proved to be slow and a function of carbon dose, time and initial ion concentration. Copper was up taken more favorably than cadmium, under same conditions, and adsorption of both cations was remarkably enhanced as a consequence of the air treatment procedure. Sequestration of the metal ions was explained on basis of the combined effect of the oxygen functional groups and the phosphorous-containing compounds; both contributing to the total surface acidity character.

Effect of Chemical Oxidation on the Adsorption Properties of Cationic Dye on Activated Carbons Prepared from Locally Atropa belladonna

“…After oxidation, this band is not observed and a broadening in the intensity of band located at 1630 cm -1 is occurred. Shoulder bands at 1458-1386 cm -1 conjugated with strong band at 1630 cm -1 may be ascribed to the presence of carboxylic acid, carbonyl-carbonates and quinones, also moieties such as C=N, C=C and NH 3 in aromatic rings [5][6][7][8][9][10][11]. Finally, the presence of C-H outof-plane bending vibrations in the aromatic ring is identified by the appearance of small bands at 800-420cm -1 .…”

“…Generally, the adsorption capacity of ACs significantly depended on their surface chemistry and is largely influenced by both quantity and type of the surface functional groups. Accordingly, many studies have considerable interests in the improvement of the surface chemistry properties of ACs via chemical oxidation and reported their relations with the adsorption of dyes and heavy metals in the last two decades [3][4][5][6][7][8][9][10][11][12][13].…”

“…Their final surface properties depend on the activation method, time of activation as well as oxidation process. Chemical activation of carbon feedstocks with H 3 PO 4 [3,6] KOH [5] and H 2 SO 4 [17,18] has attracted much attention because it causes strong polymerization through activation process. In this respect, it is substantial in the production of ACs to select low-cost raw materials that are rich in carbon content.…”

Kinetic and adsorption study of Pb (II) toward different treated activated carbons derived from olive cake wastes

“…Organosorb 10-CO consists almost purely out of micropore volumes, therefore no hysteresis was found in their N 2 adsorption-desorption isotherm. The effect of air atmosphere leads to enhanced gasification of carbon associated with generation of O-functionalities imparting surface acidity [10].…”

“…So, research efforts dealing with the process affecting the removal or reducing the level of lead ions in environmental media are urgently needed. Among the classical wastewater treatments, bio-sorption of trace metals is an alternative technique, primarily because it utilizes inactive/dead biological materials as sorbents which are generally available at low cost, nonhazardous, and abundant in nature [8][9][10]. The use of organic by-products for the preparation of activated carbons (ACs) is very attractive due to their contribution for decreasing costs of waste disposal, widely available.…”