Nano activated carbon from industrial mine coal as adsorbents for removal of dye from simulated textile wastewater: operational parameters and mechanism study

Abstract

Feasibility studies were conducted in the preparation of an effective activated carbon (AC) using the new raw Egyptian coal source called Maghara coal. Using this is eco-friendly, economical and highly available since it is a local and a natural material; thus, it was inspected for the removal of methylene blue (MB) dye from aqueous solutions. A very simple technique known as impregnation activated carbon with NaOH by chemical activation process was used. The most proper nano-activated carbon (NAC) was produced from carbonization of average particle size coal of 0.478 mm at 550 °C for 90 min. with 50% NaOH and ratio 35. The equilibrium data of MB onto the most effective prepared material was simulated using Langmuir and Freundlich isotherm models. Moreover, the adsorption mechanism of MB onto the prepared nano-activated carbon was suggested to take place as mono-layers adsorption on the homogenous active sites. The maximum mono-layers adsorption capacity was recorded as 28.09 mg/g. The morphological, chemical, and textural properties of the prepared NaOH activated carbon was investigated using TEM, Raman spectroscopy, FT-IR, and BET. Results indicated that the material was prepared at spherical shape with average diameter of 38 nm with high total pore volume of 0.183 cm3/g. The adsorption stability and reuseability of NAC was established using HCl as an eluent solution. The findings revealed the versatility of Maghara coal as a good precursor for the preparation of high quality, efficient and economical NAC. Keywords: Nano-activated carbon, Alkaline activation, Materials characterization, Textile dye adsorption