Growth kinetics of nuclei formed from different binders and powders in vertical cylindrical mixing devices

peer-reviewedGranulation is the process of forming large aggregates from fine particles using a high shear mixer. This method is used in several industries from pharmaceuticals to chemical and fertilizer production. This research will study the effect of four process variables: speed of mixer rotation in the range 100–200 rpm, powder bed mass (25–40 g), mass of the initial nucleus (0.6–2 g), and binder viscosity (water, carboxymethyl cellulose (CMC) solutions with concentrations in the range 0.5–20 g/L) on single nuclei growth kinetics in low mixing devices. The powders under study were: lactose, tea, sugar, starch, and limestone. The results show the initial size of nuclei, the initial mass of the powder bed and binder viscosity and speed of rotation all influence the rate of nuclei growth. Analysis of the stokes deformation number of the nuclei show that growth rate of the nuclei decreases as the deformation number increases whilst the percentage gain in mass of the nuclei increases with increasing deformation number. The binder viscosity was shown to have the biggest influence of the growth rate of the nuclei. Results show that difference in powder density also has an effect on the growth kinetics of nuclei. The initial position of nuclei was also shown to influence the nuclei growth rate; the closer the starting position of the nuclei to the wall of the vessel the slower the growth rate

Removal of chromium from aqueous solution using CeO2@starch nanocomposite material and olive stone in a continuous system.

This project aims to assess the potential of CeO2/Starch nanocomposite with olive stone as adsorbent materials in micro-columns for continuous removal of Cr (VI)/Cr (III) from synthetic chromium wastewater solutions. The nanocomposite material is synthesized in the lab using starch and cerium (III) nitrate hexahydrate. Micro-columns are designed to simulate the continuous treatment process. The micro-columns produce "breakthrough curves" under various conditions, allowing for the evaluation of total chromium removal. The project explores the effects of initial Cr (VI) flow rate, initial Cr (VI) concentration, and adsorbent dosage on these breakthrough curves