Biochar-based adsorbents for the removal of organic pollutants from aqueous systems; In Emerging carbon-based nanocomposites for environmental applications

Abstract

Owing to increasing industrial activity, water quality is generally depreciating around the world. Pollutants of industrial origin include inorganics and organics, which have a plethora of adverse ecological effects. Consequently, removal of these pollutants from aquatic systems is a priority. A variety of approaches including membrane filtration, advanced oxidation processes, coagulation, biological treatment, and adsorption have been used to various success rates. Of these approaches, adsorption is an attractive technique for a number of reasons, including (1) it potentially uses readily available materials, making it cost effective and thus usable in developing countries; (2) it removes a broad range of pollutants including cations and anions, organics, and inorganics; (3) it can be regenerated for repeated use and thus reduce its carbon footprint; and (4) the pollutant-ladenmaterial is a potential slow-release fertilizer and soil conditioner. Biochar, a carbon rich porous material derived from the pyrolysis of biomass under limited oxygen, is one material that holds great promise in the removal of various pollutants from aqueous systems. The characteristics of biochar are diverse depending on the biomass feedstock and the pyrolysis conditions used. This chapter explores the use of biochar in water purification and proposes ways in which the technique can be adopted for wider commercial use.