title: Efficient arsenate removal by magnetite-modified water hyacinth biochar.
abstract: Magnetic biochars (MW) prepared by chemical co-precipitation of Fe(2+)/Fe(3+) on water hyacinth biomass followed by pyrolysis exhibited important potential in aqueous As(V) elimination. In comparison, MW2501 outperformed other MWs and exhibited the highest As(V) sorption capacity which was estimated to be 7.4 mg g(-1) based on Langmuir-Freundlic model. With solution pH ranging from 3 to 10, As(V) removal efficiency by MW2501 kept stable and consistently higher than 90%. Besides, ∼100% removal of 0.5 mM As(V) can be obtained in the presence of P ≤ 0.1 mM or Cr/Sb ≤ 0.5 mM, indicating a wide applicability of MW2501 for treatment of As-containing water. The predominance of Fe3O4 on MW2501 surface was evidenced by XRD. Ligand exchange between As(V) anion and the hydroxylated surface of Fe3O4 as well as H bond was largely responsible for As(V) sorption as suggested by FTIR. XPS analysis further revealed the dominance of As(V) in the sorbed As on MW2501 surface with co-occurrence of a minor proportion of As(III) (11.45%). In parallel, oxidative transformation of Fe3O4 to Fe2O3 was also suggested by XPS. By a lab-scale column test, the potential and suitability of MW2501 in As-containing water treatment was further confirmed, which could also provide an alternative way to manage and utilize this highly problematic invasive species.
authors.affiliation: College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China; 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: Feng
authors.initials: F
authors.lastname: Zhang
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: 1546861600@qq.com.
authors.forename: Ji
authors.initials: J
authors.lastname: Xionghui
authors.affiliation: College of Resources and Environmental Science, Hunan Normal University, Changsha, Hunan, 410081, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Ma
mesh_terms: D000327:Adsorption; D001149:Arsenates / Q000302:isolation & purification*; D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D031806:Eichhornia; D005290:Ferric Compounds / Q000737:chemistry; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D058865:Introduced Species; D013057:Spectrum Analysis; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification
chemical_list: D001149:Arsenates; D005290:Ferric Compounds; D014874:Water Pollutants, Chemical; C540010:biochar; D002606:Charcoal; C025657:arsenic acid; D052203:Ferrosoferric Oxide
keywords: Arsenic; Invasive species; Magnetic biochar; Sorption behavior; Sorption mechanisms