Biomass‐derived hydrochars as eco‐friendly adsorbents for wastewater treatment applications

Abstract Emerging organic pollutants (EOPs), such as diethyl phthalate (DEP), bisphenol A (BPA), and methylene blue (MB), are only partially removed in conventional wastewater treatment plants. This study assesses hydrochars produced by hydrothermal carbonization (HTC) of spruce bark (SB), vine shoots (VSs), and wheat straw (WSs) for removing three representative EOPs at environmentally relevant concentrations. HTC produced hydrochars with distinct physicochemical properties and pollutant affinities. SB‐hydrochar exhibited the highest surface area (20 m 2 /g) and an acidic surface, promoting adsorption of cationic MB and moderately hydrophobic BPA. VSs‐hydrochar, despite low porosity (<5 m 2 /g), showed strong affinity for DEP in real wastewater, achieving 3.8 mg/g (86% removal), likely due to π–π interactions and matrix effects. WSs‐hydrochar displayed lower porosity but maintained relevant MB uptake. MB showed the highest adsorption (4.8–4.9 mg/g), while BPA exhibited moderate removal (1.7–2.6 mg/g). These results highlight the potential of hydrochars as low‐cost, sustainable adsorbents for removing EOP from wastewater.