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Abstract-The present investigation focuses on testing the adsorptive behaviour of laboratory synthesized titania nanofibers towards Hg(II) and Pb(II) in the aqueous system. The BET analysis confirmed that the electrospinned nanofibers were confirmed to possess a large surface area of 740 m 2 /g. The fiber mats were analysed by EDX, which confirmed the adsorption of the metals on the fiber surface. SEM revealed the smooth morphology and continuous nature of the fibers. The effect of pH, contact time and adsorbent dose is compared for both the metals. At the most optimized conditions, highest uptake of 95.5% was observed for 0.01 mg/L Hg(II) concentration while it was 83.8% for 0.5 mg/L Pb(II) concentration. Since the rate limiting steps in adsorption are of vital importance in order to define the rate parameters for design purposes, the present study takes into account Weber and Morris and Boyd mass transfer diffusion models for both Hg(II) and Pb(II) adsorption on titania nanofibers. The equilibrium data were then analyzed using Langmuir and Freundlich sorption models and the characteristic sorption parameters for each isotherm were determined. The discussion also focuses on few of the recently used adsorbents for heavy metal uptake and their comparison with the present study.Index Terms-Adsorption, heavy metals, isotherm, mass transfer, nano adsorbent.

Microfluidic devices are quite important for process industries, as these devices can intensify heat and mass transfer in two-phase reaction systems. Two-phase reaction systems, such as gas-liquid and liquid-liquid reactions with certain limitations have already been carried out in microfluidic systems by a few authors. However, these concepts are still under development and a detailed understanding of the hydrodynamics involve is required. Hydrodynamics studies are inherently crucial to provide precise reaction conditions and identify asymptotic performance limits. In the present work, Computational Fluid Dynamics (CFD) simulation was carried out to investigate the hydrodynamics involved in the T-junction enhanced microchannel. The slug formation, slug size, slug shape, and pressure drop in the enhanced microchannel were predicted using the volume of fluid (VOF) for water-cyclohexane system. The effects of obstruction spacing on pressure drop, slug lengths, and mixing within the slug were also examined. This study revealed that mixing enhances tremendously within the slug and at the interface in the enhanced microchannel, but with slightly greater pressure drop. However, an increase in obstruction spacing affects the slug formation, unit slug length, and pressure drop.