Digestate and Sludge-Derived Biochar for Contaminant Removal in Water and Wastewater Treatment

The growing volumes of anaerobic digestate and sewage sludge generated by wastewater treatment and biogas facilities represent both a disposal challenge and an underexploited resource. Converting these residues into biochar through pyrolysis offers a pathway to close the loop between waste management and water treatment: a low-cost, carbon-rich adsorbent produced from a waste stream that would otherwise require costly disposal or land application. This aligns with circular economy principles by transforming a liability into a functional material capable of removing heavy metals, organic micropollutants, pathogens, and emerging contaminants from water and wastewater.Compared to conventional biochar feedstocks (agricultural residues, wood biomass), digestate- and sludge-derived biochars present distinct physicochemical properties - variable mineral content, nutrient loading, and surface functional groups - that influence their adsorption capacity, stability, and potential for contaminant leaching or re-release. These characteristics need targeted investigation to establish whether such biochars can perform reliably and safely as water treatment materials at scale.This Research Topic aims to consolidate current knowledge and advance research on the production, characterization, and application of digestate- and sludge-derived biochar for contaminant removal in water and wastewater treatment. We welcome contributions addressing production optimization, adsorption mechanisms, treatment performance, environmental safety, and economic or life-cycle feasibility of these materials, with the goal of supporting their transition from laboratory studies to practical, scalable treatment solutions.We welcome submissions on, but not limited to, the following topics:- Production and pyrolysis optimization of biochar from anaerobic digestate and sewage sludge (temperature, residence time, feedstock blending)- Physicochemical characterization of digestate/sludge-derived biochar and structure-performance relationships- Adsorption mechanisms and removal efficiency for heavy metals, emerging contaminants, pharmaceuticals, and pathogens- Comparative studies of digestate/sludge biochar versus conventional biochar feedstocks for water treatment- Risk assessment of contaminant leaching, nutrient release, or secondary pollution from sludge-derived biochar- Integration of biochar-based treatment into existing water/wastewater treatment trains- Techno-economic and life-cycle assessments of sludge/digestate biochar production and application- Regeneration, reuse, and end-of-life management of spent biochar- Field-scale or pilot studies demonstrating real-world treatment performance Topic editors: Sridhar PILLI, Pranav Deepak Pathak, Pedro Neves Carvalho Source: https://www.frontiersin.org/research-topics/85629/digestate-and-sludge-derived-biochar-for-contaminant-removal-in-water-and-wastewater-treatment