Hydrochar and Its Composites for Highly Efficient Pollutant Removal

Abstract

Water pollution caused by industrial effluents without prior purification treatment represents one of the serious environmental concerns in contemporary times. Lately, due to its surface characteristics, pronounced chemical reactivity, and efficient regeneration ability, hydrochar obtained by hydrothermal carbonization of waste biomass has been explored as sustainable adsorbents for the removal of different pollutants. Besides, potential disadvantages of this material, such as low specific surface area and porosity, are easily overcome by surface modifications and composites synthesis. Previous reported studies have shown that chemical methods that include hydrogen peroxide or alkalis treatment, and incorporation of metals onto hydrochar surface can significantly improve its adsorption performances. Within this study, the potential application of hydrochars from different precursors and its composites as efficient sorbents of organic dyes and heavy metals from aqueous solutions will be discussed. Special attention will be directed towards structural changes caused by modification, achieved adsorption capacities and potential adsorption mechanisms. In general, the valorisation of hydrochar as a polluter sorbent solves the problems of sustainable and efficient material for purification and disposal of waste with permanent consequences to the environment.