Abstract
The current study aims to efficiently utilize nanomaterials as an ecological protective tool to maintain a safe environment safe, preserve human health, and support societal welfare via improving water chemical quality. Practically, carbon nanotubes (CNT), as chemical adsorbents, were evaluated for their capacity to remove both lead and copper ions from water. The governing factors and parameters potentially influencing the Pb-Cu adsorption capacity of the nanoadsorbent, e.g., the initial concentrations of adsorbates, the dosage of adsorbent, and contact time were also evaluated. The removal extent (%) of lead and copper was found to be inversely correlated with the initial metal concentration; it decreased when the metal concentration increased from 50 to100 mg\L. CNT was more effective in removing lead than copper, with a better removal efficiency of both ions (50 and 100 mg\l) reaching more than 80%. Under the optimal conditions, the concentrations of lead and copper at 50 mg/L were reduced to 1.1 and 1.8 mg/L (pH 7, contact time 180 min, and bio-sorbent dosage 50 mg). At both dosages (50 and 100 mg), the amount of both lead and copper adsorbed into CNT was significantly lower in the competitive adsorption (binary solution) than in the single ion adsorption. With regard to the dynamic behavior of CNTs, a zero-order model was employed to describe the kinetic adsorption process of Pb and Cu into CNT. The low dose (50 mg) was associated with significantly higher levels of net profit per liter of water and benefit-cost ratio (BCR), as well as substantially lower costs. The efficiency of heavy metal removal was found to be positively correlated with the CNT dose. Therefore, CNT can be considered an efficient and cost-effective nanoadsorbent, capable of rapidly removing water contaminants at a relatively low dose and low cost.