Effect of carbonization temperature in the production and utilization of green carbons for chromium (VI) removal
Author(s): M Padmaja and R Bhavani
Abstract: The paper has focused on the challenges/impacts of tannery effluent and evaluates the alternative treatment options used to treat, recover or recycle chromium from the waste water. The study on performance of vetiver root biomass (VRB) powder in this study investigates the production of using chemical activation in the removal of Chromium (VI) ion from aqueous solution in continuous mode using fixed bed column. Activated carbon (VRB-AC) was prepared from the pyrolysis at different temperatures (550 ⁰C, 750 ⁰C and 900 ⁰C, 1 h) using impregnated with 1:1 KOH under inert atmosphere (Nitrogen). Resulting in an activated carbon with the highest surface area was chosen for subsequent studies and was characterized for its functional groups using FTIR spectrum. It can be concluded that adsorbent VRB prepared using a 1:1 impregnation ratio has the highest … Spectrum. Thus, this study demonstrated the potential of using VRB as cheap and efficient raw materials to produce activated carbon for the treatment of industrial effluents.Optimal conditions for the activation stage were obtained at 800 °C and a hold time of 1 h in the case of activation with carbon dioxide and at 700 °C and a hold time of 1 h in the case of activation with steam. The maximum functional groups were present in VRB achieved by Nitrogen activation were of 789m2/g and 0.3268 cm3/g. The characterization of materials was done using TGA, BET, XRD, SEM, and FTIR. The SEM images ofMIL-101 showed octahedral crystal structure and composite materials exhibited the same morphology asMIL-101(Cr) crystals onan activated carbon bed. The BET surface area of AC and AC/MIL-101(Cr)5% was measured 1096.83 and2412.1 m2/g, respectively. A comparative study has also been done on the adsorption capacity of VRB powder of various particle sizes. It was found that the metal uptake capacity (amount of removal) of Chromium (VI) ion decreased but the adsorption capacity (percentage of removal) increased with the decrease in the concentration of chromium (VI) in the initial sample solution. It was also observed that the order of metal uptake capacity & adsorption capacity of VRB powder passing through various sieve sizes for removal of Chromium (VI) removal was as follows: 150 micron > 300 micron > 600 micron.