Preparation of carbonaceous materials from flotation-sludge of the poultry industry and its application in the methylene blue adsorption

In this work, different carbonaceous materials based on floated sludge from a poultry industry wastewater treatment plant (PI-WTP) were synthesized. These materials were characterized and investigated in methylene blue dye (MB) adsorption. The influences of the initial pH solution, adsorbent dosage, kinetics, equilibrium, and thermodynamics were evaluated in the adsorption experiments. A simulation of a real textile effluent was also carried out to evaluate the adsorbent. The results of the adsorbents' characterization demonstrated that adding ZnCl2 + lime, followed by pyrolysis and acid leaching, significantly improved the material's properties, leading to abundant porosity and high surface area. The adsorption experiments indicated that the natural pH of the solution (8.0) and the AC-II dosage of 0.75 g L-1 are optimal for MB removal. Elovich and Sips' models (with a maximum adsorption capacity of 221.02 mg g(-1) at 328 K) best fitted the experimental kinetic and equilibrium data, respectively. The adsorption process is spontaneous and endothermic according to thermodynamic parameters. The discoloration efficiency of the simulated effluent was 67.8%. In conclusion, the floated sludge, a residue produced on a large scale that needs to be disposed of correctly, can be converted into a value-added material (carbonaceous adsorbent) and applied to treat colored effluents.

Automated summary

In this study, carbonaceous materials were synthesized from floated sludge obtained from a poultry industry wastewater treatment plant. The materials were characterized and studied for methylene blue dye adsorption. The adsorption experiments evaluated the impacts of initial pH solution, adsorbent dosage, kinetics, equilibrium, and thermodynamics. The results showed that the addition of ZnCl2 + lime, followed by pyrolysis and acid leaching, significantly improved the properties of the materials, resulting in increased porosity and surface area. Optimal conditions for MB removal were found to be a natural pH of the solution (8.0) and an AC-II dosage of 0.75 g L-1. Elovich and Sips' models were found to best fit the experimental kinetic and equilibrium data, respectively. The adsorption process was determined to be spontaneous and endothermic based on thermodynamic parameters. The simulated effluent achieved a discoloration efficiency of 67.8%.