Use of Different Types of Biosorbents to Remove Cr (VI) from Aqueous Solution

Abstract

This article summarizes the results of a research study that was focused on the possibility of removing Cr (VI) from aqueous solution, using low-cost waste biomaterial in a batch mode. A set of seven biosorbents was used: Fomitopsis pinicola, a mixture of cones, peach stones, apricot stones, Juglans regia shells, orange peels, and Merino sheep wool. Three grain fractions (fr. 1/2, fr. 0.5/1.0, and fr. 0/0.5 mm) of biosorbents were studied. The aim was to find the most suitable biosorbent that can be tested with real samples. The influence of other factors on the course of biosorption was studied as well (chemical activation of the biosorbent, pH value, rotation speed during mixing, temperature, and the influence of biosorbent concentration). The use of chemical activation and adjustment of the pH to 1.1 to 2.0 make it possible to increase their sorption capacity and, for some biosorbents, to shorten the exposure times. Two kinetic models were used for the analysis of the experimental data, to explain the mechanism of adsorption and its possible speed control steps: pseudo-first and pseudo-second-order. The pseudo-second-order kinetic model seems to be the most suitable for the description of the experimental data. The thermodynamic parameters suggest that the biosorption was endothermic and spontaneous. In the biosorption equilibrium study, the adsorption data were described by using Langmuir and Freundlich adsorption isotherms. The Langmuir model was applicable to describe the adsorption data of all biosorbents. Both models are suitable for chemically treated sheep fleece and peach stones.

Removal of Cadmium, Copper, and Lead From Water Using Bio-Sorbent From Treated Olive Mill Solid Residue

“…where q (adsorption capacity) is the amount of solute adsorbed per unit weight of sorbent at equilibrium measured in mg/g, C f is the adsorbate equilibrium concentration in solution measured in mg/L, q max is the maximum adsorption capacity measured in mg/g, and b is Langmuir adsorption constant (L/mg). 65 - 67 …”

“…where q (adsorption capacity) is the amount of solute adsorbed per unit weight of sorbent at equilibrium measured in mg/g, C f is the adsorbate equilibrium concentration in solution measured in mg/L, q max is the maximum adsorption capacity measured in mg/g, and b is Langmuir adsorption constant (L/mg). [65][66][67] The term q max is assumed to represent a fixed number of surface sites in the sorbent, and it should be constant and temperature-independent. It is determined merely by the nature of the sorbent.…”

Versatile Applications Of Biopolymer Nanocomposites: A review

“…Catalysis is one of the vital methods associated with chemical modifications, which is very important for the development of industries. [109] As the important thing elements in catalysis, catalysts participate within the chemical reaction in a particular direction without themselves being fed on and they determine the costs of the reaction. Ideally, catalysts can convert a massive amount of reactants, while eating fewer materials under mild reactive situations.…”

Application of the Biomass from the Shell of Pachyrhizus erosus in the Removal of Hexavalent Chromium from Contaminated Waters

“…4), using a Corning Pinnacle 530 model pH meter and 1 M HNO 3 to keep the pH value constant, since the capture speed is controlled by the time at which the adsorbate it is transported from the outside to the inside of the bioadsorbent particles [15]. These results are least efficient for those reported with the biomass of macromycete A. bisporus, which the removal was 100% at 21 minutes [7], for the C, sativum biomass, when the highest removal was observed within 3 hours, with 1.0 g of natural biomass, and 28°C [8], for the A. comosus biomass shell, the highest biosorption of the metal (100 mg/L) occurs within 10 hours, at pH of 1.0, 28°C with 5 g of natural biomass [9], too an optimum time of 2 and 4 hours for the removal of Chromium (VI) by Macadamia nutshell powder [10], 2 hours for the modified Oyster shell types, and chemically modified dried water hyacinth roots [11,12], an optimum time of 10 minutes using orange peel and wheat bran, for the removal of Chromium (VI) from wastetewater [16], 6 hours for Chromium (VI) removal and total Chromium biosorption from aqueous solution by Quercus crassipes acorn shell [17], 30 minutes for the decontamination of the same metal on modified chicken feather [18], and 80 and 50 minutes with orange peels and Fomitopsis pinicola [19]. On the other hand, the highest metal adsorption was observed at a pH of 1.0 with the analyzed biomass (Fig.…”

“…On the other hand, the highest metal adsorption was observed at a pH of 1.0 with the analyzed biomass (Fig. 4), and this is probably what the dominant species (CrO 4 2and Cr 2 O 7 2of Cr ions in solution, interact more strongly with the ligands carrying positive charges [20,21], and this is like that reported for the fungal A. bisporus, C. sativum, and A. comosus biomass, which the optimum pH of removal was 1.0 [7,8 and 9], too the same pH valor using orange peel and wheat bran, Q. crassipes acorn shell, and modified chicken feather [16,17 and 18], a pH between 1.1-2.0 using different types of biosorbents (F. pinicola, a mixture of cones, peach stones, apricot stones, Juglans regia shells, orange peels, and Merino sheep wool to removal Chromium (VI) from aqueous solution [19]. But these results are different for the adsorption ability for toxic chromium (VI) ions in aqueous solution of some modified Oyster shell types, in which is reported an optimum pH of 6.0 [11], a pH of 3.0 for the chemically modified dried water hyacinth roots [12], a pH of 9.0 for calcite based biocomposites [22], and an optimum pH of 2.0 for the bioremotion with Arequipeña papaya seed (Vasconcellea pubescens) for total chromium removal [23].…”