Biochar: A Potent Adsorbent

Biochar has emerged as a promising treatment solution for global water and air pollution problems due to its abundant feedstock, low cost, and adaptable physical and chemical properties. Numerous studies have demonstrated biochar’s effectiveness in adsorbing contaminants from water and air due to its high surface area, ease of surface modification, and potential for regeneration and disposal. Biochar has been shown to effectively remove heavy metals, organic pollutants, and nutrients from water and air. Moreover, biochar production can be environmentally friendly by utilizing organic waste materials as feedstock. Overall, adsorption performance is influenced by biochar characteristics, contaminant concentration and characteristics, operating conditions, adsorbent dosage, temperature, contact time, solution pH, and the presence of interfering species. The main factors impacting biochar characteristics are feedstock type, pyrolysis conditions, and activation or modification method. Furthermore, the complex structure of biochar makes adsorption a complicated process with the possibility of different adsorption mechanisms such as electrostatic interactions, π-π interactions, hydrophobic interaction, surface complexation, and others. This chapter discusses the effects of biochar characteristics on its adsorption performance. Furthermore, the improvements in the use of biochar to adsorb inorganic and organic contaminants from air and water are explained, and the mechanisms of adsorption by overviewing the connections between the characteristics of biochar and its adsorption performance are discussed. Finally, the opportunities and limitations of using biochar in adsorption systems and its industrial applications are discussed, and potential future research directions are proposed.