Agricultural waste-derived biochar in heavy metals remediation of soil-food crops for human health and sustainable agriculture

ABSTRACT Heavy metals (HMs) contaminations in ‘soil and food crops’ interface perturb food safety, soil quality, environmental sustainability, and public health. In global agricultural landscapes, challenges are further exacerbated by agricultural-waste biomass burning-driven emissions of hazardous particulate matter, black carbon, and greenhouse gases. Together, environmental repercussions are realized as pollution, land degradation, climate change, and expanding marginal lands. This discussion therefore explores biobased methods associated with ‘agricultural waste-derived biochar (ARBC)’ for HMs remediation, wise management of crop harvesting/processing residues or left-over remnants in farmlands by biomass valorization, and sustainable agriculture. Further, multiple mechanisms and physico-chemical attributes are explored with ARBC deployments to leverage HMs remediation from agroecosystems in an eco-sustainable way. In this respect, the designer ARBC, especially those manoeuvred with magnetic and nano-scale particles offer better potential to deal with HMs remediation from soil-food crops. However, critical analysis revealed that the success of ARBC-technology in decontaminating HMs contaminated soil-food crops is tightly regulated by multiple factors such as pyrolysis conditions, application doses, biochar-microbe interactions, soil physico-chemical characteristics, and nature of feedstocks. In conclusion, sustainable ARBC applications should ensure abridging of biobased technology driven HMs remediation and human health risks mitigation. Last, the limitations in techno-economic and life cycle assessment need to be urgently addressed for scale-up of biobased technology in the HMs remediation. Future researches to conquer the limitations in secondary pollution from aged ARBC and nanotoxic effects of designer biochar can benefit stakeholders, global regulatory institutions, and policymakers for designing eco-sustainable future. Such panoramic advancements in biomass-driven technology for soil pollution remediation and human well-being can leverage biorefinery, boost circular bioeconomy, facilitate decarbonization, and accelerate climate action to help achieve ‘United Nations-Sustainable Development Goals’.