This chapter provides a better view of the principles of the biosorption process by comparing with other conventional methods. Biosorption is an emerging and attractive technology by which the desired substances are removed from aqueous solution by biological substances. The dye removal and decolorization were 87.5% and 91.4%, respectively, by the biosorption process. The biosorption equilibrium data were well explained by the Langmuir adsorption isotherm, and the kinetic studies showed that the biosorption process followed the second-order model. Biosorption of cationic basic dye and cadmium by the biosorbent Bacillus catenulatus JB-022 strain was investigated by Kim et al. FT-IR analysis was performed to analyze the surface features of the biosorbent involved in the biosorption process. Industrial effluents including dyes, heavy metals, polyaromatic hydrocarbons, phenols, pharmaceuticals, organic waste, pesticides and microbial colonies has been reportedly released into water.