Biochar as a Filter Media for Air Pollution Control Systems

Biochar is a renewable biomaterial that can be produced at a low cost and has a variety of applications. Some of these applications include the amendment of soil, the lessening of greenhouse gases’ emissions, and the elimination of inorganic and organic contaminants from aqueous systems. Recent studies have accumulated growing evidence indicating that biochar possesses the ability to eliminate all gaseous chemical pollutants present in the flue gases of industrial facilities. However, unlike its applications in agro-ecosystems, soil supplements, and aquatic systems, there is still a lack of comprehensive evaluations of its uses in air pollution control. This study aims to examine the available data to acquire a deeper understanding of the contaminants, particularly gaseous contaminants, as well as potential uses, limitations, and future research requirements relevant to the use of biochar in mitigating air pollution. This book chapter provides a brief overview of the synthesis of biochar and their functionalized derivatives, as well as the features that influence their potential to remove gaseous pollutants. The ability of biochar to remove a wide variety of inorganic and organic gaseous pollutants as well as the mechanisms behind this process are examined. Biochar has been shown to effectively eliminate metal vapour, specifically elemental mercury (Hg), as well as acidic gases (SO2, CO2, and H2S), organic pollutants such as aromatic compounds, odorous chemicals, and volatile organic compounds and nitrogen oxides (NOx). This chapter discusses various techniques for removing gaseous contaminants, such as adsorption, precipitation, and size exclusion. These methods have the potential to remediate gaseous emissions from various industrial applications, including incinerators, smelters, waste-to-energy systems, wastewater treatment facilities, and agro-related systems such as cattle farms. The renewable, sustainable, and cost-effective nature of biochar, coupled with its potential industrial applications, suggests significant opportunities for the further development and expansion of biochar application in the field of air pollution control.