The role of biochar in heavy metal-contaminated wastewater and soil treatment: A Comprehensive review

Abstract

As a result of water shortages, farmers are forced to use wastewater as an irrigation source for agricultural land, primarily for vegetables. Although wastewater contains abundant plant nutrients and are always readily available, it also contains hazardous contaminants, including heavy metals. Wastewater contains dangerous levels of heavy metals, particularly lead (Pb). Vegetables irrigated with Pb-contaminated wastewater create growth and yield problems and pose serious health risks to those who consume them. Thus, increased global demand for soil remediation is driven by concerns about heavy metal contamination. Toxic metals are prevented from entering food crops by using biochar as a low-cost biosorbent, which can immobilize heavy metals in wastewater-irrigated soil. Sorption, redox state alteration of heavy metals, soil pH modification, and precipitation are just some of the many mechanisms by which biochar can immobilize metals in soil. This can boost crop development and yield while also lowering human health risks. Soil heavy metals can be immobilized by several methods using biochar's features, like its high surface area and wide pH range, as well as its long-term stability and the presence of oxygen-containing functional groups. This review focuses on using biochar to reclaim soil and water that have been contaminated by heavy metals as well as to fertilize plants.