Development of low-carbon and porous biochar-slag composites for efficient phosphorus removal

_UC, while exhibiting more moderated effluent chemistry, including lower and more stable electrical conductivity (∼600 μS/cm), lower TOC release, and post-operational P immobilisation of 38.91 mg/g. SEM-EDS mapping and fractionation revealed Ca-P precipitation was the dominant removal mechanism. This study proposed a scalable, low-carbon route for sustainable P remediation.