Continuous removal of malachite green by calcium alginate immobilized Bacillus cereus M116 in packed bed column

• Biosorption of malachite green in continuous up-flow packed bed column reactor.
• Flow rate, bed height, influent dye concentration are important process parameters.
• Adam–Bohart, Yoon–Nelson and Thomas models employed for experimental data analysis.

Continuous removal of malachite green from synthetic dye solution (pH 5.0) was studied with Bacillus cereus  M116 immobilized in calcium alginate (3%) using a packed bed column reactor operated at 30 °C. The experiments were conducted to study the effect of important parameters such as flow rate, bed height and influent dye concentration on the dye removal process. Maximum dye removal (74.7±0.4%74.7±0.4%) was observed at 2 mL/min flow rate, 30 cm bed height and 100 mg/L influent dye concentration. The Adam–Bohart model, Yoon–Nelson model and Thomas model were employed to determine characteristic parameters such as saturation concentration (N0), kinetic rate constant (KAB, KY N, KTh), maximum biosorption capacity (q0), and the time required for 50% adsorbate breakthrough (ττ), which are all useful for process design. Maximum biosorption capacity of 37.21 mg/g was obtained at optimum conditions. Experimental data fitted well with Adam–Bohart model at initial part of the breakthrough curve.