Nano zero-valent iron supported on activated carbon: Effect of AC/nZVI ratio on removal of nickel ion from water

The present study investigated the possible effect of contact time, initial nickel concentration, and adsorbent concentration on removing Ni (II) ion, which is toxic to living organisms, from the aqueous media using nano zero valent iron (nZVI) and nano zero valent iron coated powdered activated carbon. A large portion of the nickel removal was achieved in a contact time of five minutes. A removal efficiency of barely 24% was able to be achieved only using activated carbon, while the nickel removal was achieved by approximately 80% using 200 mg/L nZVI. On the other hand, the efficiency was observed to increase up to 99% even with the particle containing the lowest nZVI in the experimental studies using the AC-nZVI nanoparticles containing AC at a rate of 25%, 50% and 75%. Adsorption capacity was increased from 125 mg/g and 820 mg/g for activated carbon and nZVI, respectively to 1190 mg/g for 50% AC-nZVI. Based on our study results, the effect of nZVI is promoted when nZVI is synthesized together with activated carbon. The Freundlich model was also found the best to represent the isotherm modeling made for nZVI.