Synthesis of TiO\(_2\) Impregnated Ribes nigrum Stem Nanoactivated Carbon and their Application to Remove Heavy Metals

Nanoactivated carbons from Ribes nigrum (black currant) stem were prepared using two-step procedure with excellent yield and were characterized using different spectroscopic techniques. The FTIR spectroscopy revealed O-H, C=C, C=N, and C-O stretching. XRD analysis revealed the particle sizes as 29.57 nm for stem activated carbon (SAC) and 26.55 nm for stem activated carbon impregnated with titanium (SAT) while, the morphology of the SAC and SAT were revealed by SEM to be spherical, granular and porous. The prepared nanoactivated materials were used for removal of Pb2+ and Cd2+ from aqueous solution. The influences of initial metal ion concentration, agitation time, adsorbent dose, temperature and pH were studied in batch experiments at room temperature. The adsorption equilibriums were rapid at 60 min of agitation for Pb2+ and Cd2+ on SAT with appreciable %removal. The adsorption data for Pb2+ and Cd2+ on SAT fitted well into Freundlich isotherm than Langmuir given correlation coefficient (R2) very close to unity and appreciable maximum adsorption capacity KF > 1.00. The fitting into Freundlich indicates multilayer coverage on the adsorbents. The kinetic studies showed good correlation coefficient for a pseudo-second order kinetic model for the SAT. The enthalpies of the adsorption process are: +12.754 and +18.377 KJ mol-1 for Pb2+ and Cd2+ on SAT respectively. The entropies of the adsorption process were also evaluated and have been found to be +41.805 and +12.151 KJ mol-1 for Pb2+ and Cd2+ on SAT. The results showed that SAT has the potential to be applied as alternative low-cost nanoadsorbents in the remediation of metal contamination in water.