Assessing the loading capacity of walnut peels as a nanobiomass for the biosorption of certain heavy metals from wastewater
Więcej
Ukryj
1
Biology department, College of Science, University of Anbar –Iraq
J. Ecol. Eng. 2025; 26(2):169-182
SŁOWA KLUCZOWE
DZIEDZINY
STRESZCZENIE
Abstract
Bio-removal of heavy metal pollution remains a major challenge in environmental biotechnology. This paper focuses on the potential of carbon nanoparticles for biosorption of zinc, copper, and cadmium ions from aqueous solutions, employing economical and environmentally sound plant wastes. Walnut peels were washed by distilled water, mixed with KOH, burned at 650°C, and treated ultrasonically to obtain carbon nanoparticles. Standard solutions of the heavy metals under study were prepared based on calculations of the molecular weights of the relevant metal salts Zn, Cu, and Cd, the metal ions were estimated in both treated and wastewater sample. The experiment included evaluating the effect of some environmental factors on the process of biosorption of heavy metals from wastewater to choose the optimal conditions for the adsorption process. These environmental factors included the initial metal concentration, pH, temperature, retention time, and biomass. The optimum conditions of initial metal concentration, pH, temperature, retention time, and biomass were recorded as 100 mg/l, pH of 7, 45°C., 60min., 0.2 g respectively. These results were supported by XRD examination, which indicated the presence of two Bragg diffraction peaks in the carbon nanoparticles, and TEM results also indicated the presence of inhomogeneous particles, as well as the irregular shape of the surface of the carbon nanoparticles with a large surface area, according to SEM examination. However, the optimal adsorption conditions were applied in a laboratory treatment unit, which showed its efficiency in removing heavy metal ions from wastewater. Carbon nanoparticles derived from walnut shells can be employed as excellent adsorbents for removing heavy metal ions from aqueous solutions.