Biochars as Adsorbents of Pesticides: Laboratory-Scale Performances and Real-World Contexts, Challenges, and Prospects

Rising concerns about pesticide contamination in water bodies have driven the development of technologies to mitigate the water crisis. Recognized for its adsorption effectiveness and affordability, biochar is considered a sustainable adsorbent for water treatment. This review critically examines recent studies on biochar’s application for pesticide removal. It addresses (i) the effectiveness of biochar and its relationship with pyrolysis conditions and modification strategies; (ii) mechanisms and properties controlling pesticide adsorption; (iii) real-world applications and large-scale implementation; and (iv) challenges and future research perspectives. Biochar’s performance is highly dependent on precursor biomass, pyrolysis conditions, modification techniques, and pesticide properties. Among the 76 works evaluated, the number of pesticides studied is limited compared to the variety in use globally, with atrazine present in 22% of them. Issues regarding compliance with regulatory standards, potential environmental risks, and the need for greener modification techniques require further investigation. Biochar faces competition from other adsorbents, and the lack of production standards may hinder its adoption. Future research should optimize biochar under real environmental conditions and evaluate its economic and environmental impacts to support broader, sustainable applications. Collaborations among scientists, government officials, farmers, and the industrial sector are advisable to foster innovative initiatives in this field.