Unveiling the Potential of Novel Struvite–Humic Acid Composite Extracted from Anaerobic Digestate for Adsorption and Reduction of Chromium

A novel struvite–humic acid composite (S–HA) was derived from an anaerobic digestate and evaluated for the adsorption reduction of chromium [Cr (VI)] in this study. The results indicated that contains higher contents oxygen-containing aromatic functional groups (47.05% 34.13%, respectively) a specific surface area (19.3 m2 g−1). These special characteristics S–HA contributed to its capacity (207.69 mg g−1 254.47 pseudo-first second-order kinetic models, chromium. Furthermore, XPS analysis showed portion bonded Cr (VI) reduced (III) by carboxyl hydroxyl groups, which oxidized changed into ketone phenol groups. Based on findings, it concluded phosphate–humic has outstanding adsorptive capacity. However, more research is needed fully understand potential reduction.