title: Phosphate reclaim from simulated and real eutrophic water by magnetic biochar derived from water hyacinth.
abstract: In this study, the efficiency and mechanism of aqueous phosphate removal by magnetic biochar derived from water hyacinth (MW) were investigated. The MW pyrolyzed at 450 °C (MW450) exhibited the most prominent phosphate sorption capacity, which was estimated to be 5.07 mg g-1based on Langmuir-Freundlich model. At an initial phosphorus (P) concentration of 1 mg l-1, >90% P removal was achieved over pH 3-9, but the efficiency decreased sharply at pH > 10. The presence of arsenate and carbonate could remarkably decrease P sorption, while the inhibition effects of antimonate, nitrate and sulfate were less significant. In further application of MW450 to reclaim P from eutrophic lake waters (0.71-0.94 mg l-1total P), ∼96% P removals were attained in the batch studies and the effluent P concentrations in the column tests were reduced to <0.05 mg l-1within 509-1019 empty bed volumes. As indicated by XRD, MW450 surface was dominated by Fe3O4and Fe2O3, resulting in a good ferromagnetic property of this composite (saturation magnetization 45.8 emu g-1). Based on XPS, P sorption onto MW450 occurred mainly by surface complexation with the hydroxyl via ligand exchange. These results highlighted that MW derived from highly damaging water hyacinth could provide a promising alternative for P removal from most eutrophic waters.
authors.affiliation: College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Cai
authors.affiliation: College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China. Electronic address: hdhuanjing@163.com.
authors.forename: Xin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Soil and Fertilizer Institute of Hunan Province, Ministry of Agriculture Key Lab of Agri-Environment in the Midstream of Yangtze River Plain, Changsha, 410125, China. Electronic address: jixionghui@sohu.com.
authors.forename: Xionghui
authors.initials: X
authors.lastname: Ji
authors.affiliation: College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Peng
authors.affiliation: College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China.
authors.forename: Changyin
authors.initials: C
authors.lastname: Tan
authors.affiliation: Soil and Fertilizer Institute of Hunan Province, Ministry of Agriculture Key Lab of Agri-Environment in the Midstream of Yangtze River Plain, Changsha, 410125, China.
authors.forename: Xi
authors.initials: X
authors.lastname: Huang
mesh_terms: D000327:Adsorption; D000965:Antimony / Q000737:chemistry; D001149:Arsenates / Q000737:chemistry; D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D002681:China; D031806:Eichhornia / Q000737:chemistry*; D005290:Ferric Compounds; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D060106:Lakes; D008280:Magnetics; D009566:Nitrates / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry; D055672:Static Electricity; D014867:Water; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods
chemical_list: D001149:Arsenates; D005290:Ferric Compounds; D009566:Nitrates; D010710:Phosphates; D014874:Water Pollutants, Chemical; C540010:biochar; D014867:Water; D002606:Charcoal; D010758:Phosphorus; D000965:Antimony; C025657:arsenic acid
keywords: Eutrophic water; Fe-impregnated biochar; P reclaim; Sorption efficiency; Water hyacinth