Biosorption of Acid Dye in Single and Multidye Systems onto Sawdust of Locust Bean (Parkia biglobosa) Tree

Abstract

Properties of raw sawdust ofParkia biglobosa, as a biosorbent for the removal of Acid Blue 161 dye in single, binary, and ternary dye systems with Rhodamine B and Methylene Blue dyes in aqueous solution, were investigated. The sawdust was characterized using Scanning Electron Microscopy, Fourier Transform Infrared spectrophotometry, X-ray diffraction, and pH point of zero charge. Batch adsorption experiments were carried out to determine the equilibrium characteristics, thermodynamics, and kinetics of the sorption processes. The data obtained were subjected to various isotherm and kinetics equations. The results showed that the adsorption processes were described by different isotherm models depending on the composition of the system; they were all spontaneous (ΔGranges from −0.72 to −5.36 kJ/mol) and endothermic (range ofΔHis 11.37–26.31 kJ/mol) and with increased randomness withΔSvalues of 55.55 and 98.78 J·mol/K for single and ternary systems, respectively. Pseudo-second-order kinetics model gave better fit for all the sorption systems studied irrespective of the differences in composition, with the initial and overall rate constants higher for the mixtures than for the single system (6.76 g·mg−1min−1). The presence of Rhodamine B and Methylene Blue had a synergetic effect on the maximum monolayer capacity of the adsorbent for Acid Blue 161 dye.

Kinetic and Isotherm Analysis of Cu(II) Adsorption onto Almond Shell (Prunus Dulcis)

“…Some researchers reported an increase [25,26] some reported a decrease [27][28][29] in adsorption capacity depending on the temperature and some [11] reported that the adsorption capacity did not change with changing temperature. As seen in Figure 10, temperature did not have a significant effect on the adsorption capacity in the present study. ]…”

Artificial Neural Network Approach for Modeling of Ni(Ii) Adsorption from Aqueous Solution by Peanut Shell

“…Within the interval of 20-60 °C, adsorption capacity, q e , varied between 1.92-2.15 mg/g, and efficiency percentages varied between 23-26 %. Increased adsorption capacities with increasing temperature were reported in some of the previous studies [30,55], whereas decreased biosorption capacities were also reported in others [56,57]. Some researches indicated did not have any significant effect of temperature in the biosorption process [58].…”

Characterization of Bean Husk-Based Adsorbent

“…It was also reported that the surface morphology of raw sawdust [8] which reveals an irregular and porous surface topography of the adsorbent and speculated that this may due to high surface area of the material.…”