Removal of Pyrocatechol from Aqueous Solution Using Activated Carbon Coated with Aluminum Nanoparticles by a Green Method

Abstract

Background: Pyrocatechol, a phenol derivative, is commonly found in industrial effluents at various concentrations due to its extensive use in multiple industries. These toxic compounds are resistant to biological degradation and pose significant threats to environmental and human health when they enter aquatic environments. Objectives: This study explores the removal of pyrocatechol from aqueous solutions using activated carbon coated with aluminum nanoparticles. Methods: Laboratory materials included oak wood (collected from the mountains around Lorestan province, Iran), pyrocatechol, H3PO4, HCl, Al2O3, NaCl, NaOH, graphite oxide, and NH3. This experimental study was conducted on a laboratory scale. Oak wood was used to synthesize activated carbon, while aluminum oxide and oak moss were employed to produce aluminum nanoparticles using a green method. The characteristics of the adsorbents were examined using XRD, FESEM, FTIR, and BET analyses. Parameters such as contact time (5 - 40 min), pH (3 - 11), initial concentration of pyrocatechol (20 - 200 mg/L), adsorbent dose (50 - 250 mg), and ionic strength were investigated. The residual concentration of pyrocatechol was measured using a spectrophotometer at a wavelength of 275 nm. Results: The results indicated that maximum adsorption efficiency was achieved with a pyrocatechol concentration of 100 mg/L, a pH of 7, a contact time of 20 minutes, and an adsorbent dose of 250 mg. Isotherm and kinetic analyses showed that the adsorption data correlated well with the Langmuir model and the pseudo-second-order kinetic model, respectively. Conclusions: Activated carbon derived from oak wood and coated with aluminum nanoparticles using a green method is highly efficient in removing pyrocatechol from aqueous solutions. This method is recommended as an effective, rapid, cost-effective, and environmentally friendly approach for the removal of pyrocatechol from aqueous environments.