Algal Research and Bioenergy Lab, Department of Biotechnology, Graphic Era Deemed to be University, Dehradun, 248002, India

The thermochemical process of various biomass results in the formation of a common by-product known as biochar. Biochar can be defined as a pyrogenic black carbon material obtained through different thermochemical routes of carbon-rich biomass in an inert atmosphere. The physico-chemical properties of biochar greatly influence its multidisciplinary applications like carbon sequestration, enhancement of soil fertility, wastewater remediation etc. However, in recent times, emergence of third generation feedstocks i.e., algal biomass for production of biochar has gained significant importance due to its suitable and unique features. After the extraction of particular valuable products, the algal residues can further be transformed into biochar, biofuel and biogas by several thermochemical technologies like pyrolysis, hydrothermal liquefaction, torrefaction and hydrothermal carbonization. Hence, the present review discusses about characteristics differentiation between conventional and algal biochar, various thermochemical methods for production of biochar, working mechanism of biochar responsible behind adsorption of various contaminants and its implementation in wastewater remediation purposes. In addition, it further highlights some key challenges that still require investigation for a wide scope and commercialization in upcoming future.

Keywords: Biochar; algal biomass; thermochemical; wastewater remediation