Triazine herbicides are widely used for weed control in agricultural systems, and their occurrence in water bodies has been frequently reported worldwide. This study assessed the efficiency of a hydrochar derived from the epicarp and mesocarp of passion fruit residues for the removal of three triazine herbicides (atrazine, ametryn, and metribuzin), with the aim of developing a material suitable for application in water remediation programs. The adsorption capacity of biomass and hydrochar derived from passion fruit residues was evaluated with and without activation using 0.5 mol L⁻¹ phosphoric acid. The adsorption of herbicides was not significantly affected by pH within the range of 4 to 8. The acid hydrochar, which exhibited the highest removal capacity among the evaluated adsorbents, presented adsorption capacities of 18.05, 10.83, and 5.05 µg g⁻¹ for atrazine, ametryn, and metribuzin, respectively. These values correspond to removal efficiencies of approximately 62%, 72%, and 52% at initial concentrations of 0.33, 0.25, and 0.15 mg L⁻¹. The adsorption equilibrium time varied among the herbicides, reaching 4 h for atrazine and ametryn and 5 h for metribuzin. The adsorption dynamics between the adsorbents and adsorbates were best described by the pseudo-second-order kinetic model for ametryn and metribuzin, while atrazine had a higher correlation with the Elovich equation. The Weber–Morris model did not adequately describe the adsorption process. Among the isotherms tested, the Freundlich model provided the best fit for all three herbicides. The desorption rates of the acid hydrochar were 51%, 13%, and 83% for atrazine, ametryn, and metribuzin, respectively. Therefore, hydrochar derived from passion fruit residues represents a promising alternative for the remediation of triazine herbicides.

Water scarcity has accelerated scientific interest in non-conventional water resources for irrigation. This study combined performance analysis, science mapping, and a critical interpretive synthesis of Web of Science literature published from 2020 to 2024 to evaluate not only the structure of the field, but also the strength, limitations, and practical implications of the available evidence. Publication volume increased from 122 articles in 2020 to 174 in 2024, with a peak of 190 in 2022, and collaboration networks were concentrated in Brazil, China, the Middle East, and Europe. However, bibliometric visibility did not equate to evidence maturity. The literature consistently reports potential benefits, including freshwater substitution, nutrient recovery, and greater resilience to drought, alongside unresolved risks related to salinity and sodicity, contaminants of emerging concern, pathogens, antibiotic-resistance determinants, and groundwater contamination. The critical synthesis identified five major limitations: predominance of short-term and site-specific experiments; inconsistent characterization of water, soil, and crops; scarce long-term, multi-compartment monitoring; fragmented regulatory thresholds; and limited techno-economic and adoption evidence. We therefore propose priorities centered on harmonized reporting, multi-season field trials, mixture-based and One Health risk assessment, fit-for-purpose treatment, validation of digital monitoring under operational conditions, lifecycle assessment, and context-specific regulation. Non-conventional water should not be framed as universally sustainable; its performance is conditional on source quality, treatment, crop sensitivity, soil buffering capacity, irrigation design, monitoring, and governance. The field is scientifically active, but its operational readiness remains uneven. Graphical Abstract