Biochar-based nanocomposites for industrial wastewater treatment via adsorption and photocatalytic degradation and the parameters affecting these processes

Abstract The preparation of biochar (BC) as a useful substance generated from biomass valorization via pyrolysis has attracted much attention in recent years. Moreover, widespread worries about water pollution and the issues brought on by producing and releasing massive volumes of industrial effluents have sparked research initiatives to examine practical and affordable solutions to these problems. Dyes, heavy metals, and pharmaceutical compounds are the main hazardous pollutants in industrial wastewater. As a result, biochar (BC)/biochar (BC)-based nanocomposites have been presented as a potential alternative to handle wastewater pollution with both adsorption and photocatalytic degradation processes. Such nanocomposite materials benefit from the synergistic effect of adsorption and photocatalysis to attain improved removal of pollutants from industrial wastewater. Therefore, this review aims to describe different preparation methods for biochar and biochar-based nanocomposites. Furthermore, the differences between the adsorption and photocatalytic degradation processes are discussed. BC-based nanocomposites have emerged as promising adsorbents and photocatalysts for wastewater treatment applications. To maximize the efficiency of these processes, an overview of the parameters affecting pollutants removal from wastewater via adsorption and photocatalytic degradation processes is reviewed, where biochar dose, initial pollutant concentration, pH, temperature, time, the presence of different anions, and recycling are discovered to have a significant impact on their performance. Finally, future recommendations and research directions are provided to help shape the applications of BC-based nanocomposites for wastewater treatment applications. This review offers a comprehensive evaluation of the use of biochar as a new environmental material capable of removing pollutants from wastewater. Graphical Abstract