Thermal treatment in Australia is gaining interest due to legislative changes, waste reduction goals, and the need to address contaminants risks in biosolids used for agriculture. The resulting biochar product has the potential to be beneficially recycled as a soil amendment. On-farm management practices were reviewed to identify barriers that need to be overcome to increase recycling and examine the role of pyrolysis and gasification in effectively improving the quality and safety of biochar. Key findings revealed: (1) thermal treatment can effectively eliminate persistent organic pollutants, microplastics and pathogens, and (2) more than 90% of the total heavy metals content in biosolids become immobilized when these are converted to biochar, thus reducing their bioavailability following land application. While reported research on the short-term effects of biosolids-derived biochar suggested promising agronomic results, there is dearth of information on long-term effects. Other knowledge gaps include optimisation of land application rates, understanding of rate of breakdown and fate of contaminants in soil and water, heavy metal mobility in soil and bioaccumulation or transfer to the food chain. Improved understanding of nutrients and contaminants dynamics in soils receiving biosolids-derived biochar is a pre-requisite for their safe use in Australian agriculture, and therefore it is highlighted as priority area for future research.
Thermal treatment in Australia is gaining interest due to legislative changes, waste reduction goals, and the need to address contaminants’ risks in biosolids used for agriculture. The resulting biochar product has the potential to be beneficially recycled as a soil amendment. On-farm management practices were reviewed to identify barriers that need to be overcome to increase recycling and examine the role of pyrolysis and gasification in effectively improving the quality and safety of biochar intended for land application. Key findings revealed the following: (1) thermal treatment can effectively eliminate persistent organic pollutants, microplastics, and pathogens, and (2) more than 90% of the total heavy metals content in biosolids may become immobilized when these are converted to biochar, thus reducing their bioavailability following land application. While the reported research on the short-term effects of biosolids-derived biochar suggests promising agronomic results, there is a dearth of information on long-term effects. Other knowledge gaps include the optimization of land application rates, understanding of the rate of breakdown, and the fate of contaminants in soil and water, including heavy metal mobility and redistribution in the environment by processes such as erosion and runoff following land application. An improved understanding of nutrients and contaminants dynamics in soils receiving biosolids-derived biochar is a pre-requisite for their safe use in Australian agriculture, and therefore, it is highlighted as a priority area for future research.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.