title: Engineered biochar reclaiming phosphate from aqueous solutions: mechanisms and potential application as a slow-release fertilizer.
abstract: This work explored the potential application of an engineered biochar prepared from Mg-enriched tomato tissues to reclaim and reuse phosphate (P) from aqueous solution. Findings from batch sorption experiments suggested that, although sorption of P on the biochar was controlled by relatively slow kinetics, the maximum P sorption capacity of the biochar could reach >100 mg·g(-1). Mathematical modeling and postsorption characterization results indicated that the sorption was mainly controlled by two mechanisms: precipitation of P through chemical reaction with Mg particles and surface deposition of P on Mg crystals on biochar surfaces. Most of the P retained in the engineered biochar was bioavailable and could be released equally at multiple successive extractions. In addition, the P-laden biochar significantly stimulated grass seed germination and growth. These results suggested the postsorption biochar can be cycled back directly to soils as an effective slow-release P-fertilizer.
authors.affiliation: Department of Agricultural and Biological Engineering, University of Florida, Gainesville, Florida 32611, United States.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yao
authors.forename: Bin
authors.initials: B
authors.lastname: Gao
authors.forename: Jianjun
authors.initials: J
authors.lastname: Chen
authors.forename: Liuyan
authors.initials: L
authors.lastname: Yang
mesh_terms: D000327:Adsorption; D002606:Charcoal; D005308:Fertilizers; D018525:Germination; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry*; D012639:Seeds / Q000254:growth & development; D012996:Solutions; D014867:Water
chemical_list: D005308:Fertilizers; D010710:Phosphates; D012996:Solutions; C540010:biochar; D014867:Water; D002606:Charcoal