Heavy metal pollution has become a major concern all over the world with rapid growth in industrialization, particularly Cadmium which is highly carcinogenic. Our present work is mainly focused on hydrodynamics of liquid solid circulating fluidized bed (LSCFB) and biosorption of cadmium using immobilized micro organism in a LSCFB. In this paper, work is carried out to estimate the solids circulation rate, Solids holdup using sodium alginate beads of 4mm diameter and density of 1010 kg/m3. Cadmium concentration at regular intervals was determined by EDTA titration with xylenol orange as indicator and hexamine as buffer. (1 ml of 0.05M EDTA = 5.621 mg Cd.) was determined to verify Cadmium biosorption efficiency of batch and LSCFB studies. Based on batch study 48 strain microorganism was selected for immobilization and cadmium biosorption studies. The measured solids circulation rate and solid holdup were found to be a function of the fundamental variable viz. liquid velocity, viscosity, density. The cadmium biosorption efficiency in batch and in LSCFB respectively and found to be depending on the strain of micro- organism used, time, quantity of micro-organism used and initial cadmium concentration.