Analysis of the simultaneous adsorption mechanism of ammonium and phosphate on magnesium-modified biochar and the slow release effect of fertiliser

• DOI: 10.1007/s42773-022-00150-5
• Publication Date: 2022-04-13T08:03:10Z
• Authors: Qingshan He; Xiufen Li; Yueping Ren
• Keywords: Struvite

Abstract To decrease the eutrophication caused by nitrogen (N) and phosphorus (P) in water, magnesium-modified corn stalk biochar (MgB) was prepared under synergistic impact of multi-pyrolysis temperatures Mg 2+ contents for co-adsorption ammonium (NH 4 + -N) phosphate (PO 3− ). The mechanism, slow-release performance plant application MgB were systematically studied. results showed that pyrolysis (350–650 °C) (0–3.6 g/L) not only altered physicochemical properties biochar, but also significantly affected adsorption efficacy MgB. NH -N PO accordance with Langmuir–Freundlich pseudo-second-order kinetic models (Q max = 37.72 73.29 mg/g, respectively). Based on characteristics, kinetics isotherms results, mechanism determined found to mainly involve struvite precipitation, ion exchange, surface precipitation or electrostatic attraction. Compared leaching chemical fertilizers (CF), after (MgB-A), had a more stable pH lower conductivity. Leaching MgB-A controlled both diffusion dissolution rate Mg-P. excellent long-term abundant promoted growth Zea mays L. Lolium perenne Overall, this study suggested could realize win–win outcome biochar-based fertiliser production wastewater treatment.