The present book focuses on the biologically derived adsorbent with numerous applications in wastewater treatment, metal recovery, biosensor development, and so forth. It initiates with the description of biological sources of biosorbents followed by applications of biosorbents, biosorption isotherms, assessment of biosorbents with various tools, pre-treatment of biosorbents, and its mode of action. Some less explored areas like separation of radionuclides, biosorption of volatile organic compounds, and animal-based biosorbents are also explained. This book is aimed at graduate students and researchers in bioprocess engineering, microbiology, and biotechnology.