Mechanistic understanding of the adsorption and thermodynamic aspects of cationic methylene blue dye onto cellulosic olive stones biomass from wastewater

Abstract

In the current study, the mechanistic understanding of the adsorption isotherm and thermodynamic aspects of cationic methylene blue (MB) dye adsorption onto cellulosic olive stones biomass from wastewater were investigated. The batch adsorption of MB onto the olive stones (black and green olive stones) was tested at a variety of pH, dye concentrations, temperatures, and biomass particle sizes. The adsorption thermodynamics such as Gibbs free energy, enthalpy, and entropy changes were also calculated. Moreover, the desorption studies of MB from the spent olive stones were studied to explore the re-usability of the biomasses. The results revealed that under the optimum pH of 10, the maximum MB uptake was achieved i.e. 80.2% for the green olive stones and 70.9% for the black olive stones. The green olive stones were found to be more efficient in remediating higher MB concentrations from water than the black olive stones. The highest MB removal of the green olive stones was achieved at 600 ppm of MB, while the highest MB removal of the black olive stones was observed at 50 ppm of MB. Furthermore, for almost all the concentrations studied (50–1000 ppm), the MB adsorption was the highest at the temperature of 45 °C (P value < 0.05). It was shown by the Fourier transform infrared that the electrostatic interaction and hydrogen bonding were proposed as dominant adsorption mechanisms at basic and acidic pH, respectively. While the hydrophobic-hydrophobic interaction was a dominant mechanism at neutral pH. The thermodynamic studies revealed that the adsorption process was endothermic, spontaneous, and favorable. Moreover, the real wastewater experiment and the desorption studies showed that the green and black olive stones were a cost-effective and promising adsorbents for MB remediation from wastewater on account of their high adsorption and desorption removal capacities.

Full Factorial Design for Gold Recovery from Industrial Solutions

“…A factorial design was used for optimizing similar processes with good results, our study confirming these previous findings [50,57,[62][63][64][65]. The Au (III) adsorption process depends essentially on the contact time and the initial concentration.…”

“…This study recommends Am-L-GA as a new material with superior adsorption capacity for gold retrieval from industrial solutions and confirms the ability of the factorial design for optimizing such process, cross-validating previous research [41][42][43][57][58][59][60][61][62][63][64][65].…”

One-pot synthesis of zinc oxide nanoparticles via chemical precipitation for bromophenol blue adsorption and the antifungal activity against filamentous fungi

“…In recent years, there have been growing concerns arising from the rapid pollution of water bodies around the world 1 . This is attributed to technological advancements resulting in the rapid growth of industries, and subsequently the pollution of water from industrial effluents 2 , 3 . This water pollution has significantly affected aquatic lives, made the water unsafe for drinking, and resulted in several health effects 4 , 5 .…”

Citric acid modified waste cigarette filters for adsorptive removal of methylene blue dye from aqueous solution

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