Heavy metal removal by using magnetic nanoparticles loaded onto activated carbon

Heavy metal ions such as copper٫ iron٫ nickel٫ lead etc in the environment are of major concern due to their toxicity to many life forms. Unlike organic pollutants٫ which are susceptible to biological degradation٫ metal ions do not degrade into any harmless end products [۱] and tend to accumulate in living organisms٫ causing various diseases and disorders [۲]. Heavy metal contamination exists in aqueous waste streams of many industries٫ such as metal plating facilities٫mining operation and tanneries. Therefore٫ elimination of heavy metals from water and wastewater is very important. The most widely used methods for removing heavy metals from wastewater include ion exchange٫ chemical precipitation٫ reverse osmosis٫ evaporation٫ and membrane filtration and adsorption [۳]. Most of these methods suffer from some drawbacks such as high capital, operation cost and the disposal of the residual metal sludge which are not suitable for small-scale industries. Among various techniques٫ the adsorption process used exclusively in water treatment and many studies have been carried out to find inexpensive and chemico-physically feasible adsorbent [۳]. Many reports have appeared on the development of low cost activated carbon from cheaper and readily available materials [۴]. Activated carbons with their high surface area٫ micro porous character and chemical nature of their surface have made them potential adsorbents for the removal of heavy metals from industrial wastewater.In the present study, magnetic activated carbon was used to removal of heavy metals. The removal of heavy metals from aqueous solutions with magnetic activated carbon was studied by varying the parameters such as pH, the amount of adsorbent, initial concentration, adsorption time and temperature. Analyses of heavy metals (iron, copper and lead) in the samples were down by using flame atomic absorption spectrometer (FAAS). The maximum removal percentage of Fe+۲, Pb+۲ and Cu+۲ was achieved at an adsorbent loading weight of ۰.۱ gr/L at pH=۷ after ۳۰ min. Results showed that magnetic adsorbents could be re-used for ۷ cycles.

کلیدواژه ها:

Magnetic adsorbent ، Heavy metals ، Removal