Abstract:
This study investigates the removal of Ni2+, Pb2+ and Hg2- from their aqueous solutions using iron oxide nanoparticles solvents using range of experimental approaches, including concentration of heavy metals, time of contact between nanoparticles and heavy metals and concentration of nanoparticles. For this purpose, iron oxide nanoparticles were chemically synthesized using 12g of ferric chloride (FeCl3) dissolved in 100ml of distilled water and solution was vigorously stirred for 20mins to attain 3pH. Precipitation was achieved by adding the 100ml solution of 2M NaOH dropwise under vigorous stirring. The final pH of solution was maintained 12.The prepared nanoparticles were then centrifuged at 1500rpm for 20mins.The pellets were then oven dried at 70˚C for 30mins. Batch experiments was conducted to evaluate the potential of nanoparticles to remove heavy metal ions from their aqueous solutions. Initial and final concentrations of heavy metal ions was detected using atomic absorption spectroscopy. In order to find out the effect of concentration of heavy metals, 5% and 10% solutions were prepared. Time of contact was evaluated by running the batch experiment for 10 mins, 15 mins and 20mins. The effect of concentration of nanoparticles was evaluated using 1g and 1.5g of nanoparticles for every experiment separately. An increasing trend of heavy metal ion removal efficiencies was observed when concentration of heavy metals was increased along with nanoparticle concentration and time of contact. Maximum heavy metal ions removal took place for Ni in 10% when treated with 1.5g of nanoparticles for 20mins. The original metal concentration reduced from370ppm to 85ppm showing a removal efficiency of 77%. The results of this study suggests that being magnetic in nature, iron oxide nanoparticles possess great ability to remove heavy metal irons from their aqueous solutions when considerable concentrations of nanoparticles is used for adequate amount of time of contact.
