Removal of Cu (II) Ions from Aqueous Solutions with Modified Carbon Nanotubes

Heavy metals such as copper are known as environmental pollutants and lead to irreversible damage to human health and other living organisms. This study aims to remove copper ions from aqueous solutions using a new adsorbent that includes the carboxylated Multi-Wall Carbon NanoTube (COOH-MWCNT) functionalized with 3-amino-dihydroxy benzo-indeno-furan (MWCNT-f) and in a discontinuous adsorption system. The results showed that MWCNT-f adsorbent can act as an effective adsorbent for the removal of copper ions so the maximum removal efficiency was 90.2% (pH 6, adsorbent mass: 0.3 g, and contact time: 45 min). The kinetic process of copper adsorption onto the mentioned adsorbent was found to fit the Morris-Weber kinetic model. Moreover, the equilibrium adsorption data indicated that Langmuir isotherm covers the equilibrium data with a maximum adsorption capacity of 16.78 mg/g for MWCNT-f. It was found the temperature increase possesses a positive effect on the removal efficiency of ions and it was achieved 95.76% at 50°C. The thermodynamic parameters demonstrated that the adsorption of copper on MWCNT-f, in the studied conditions, was spontaneous and thermosetting. The present study provides a new recyclable and efficient adsorbent for the removal of Cu (II) ions from aqueous solutions