title: Stabilization of Pb(II) accumulated in biomass through phosphate-pretreated pyrolysis at low temperatures.
abstract: The remediation of heavy metal-contaminated soil and water using plant biomass is considered to be a green technological approach, although the harmless disposal of biomass accumulated with heavy metals remains a challenge. A potential solution to this problem explored in this work involves combining phosphate pretreatment with pyrolysis. Pb(II) was accumulated in celery biomass with superior sorption capacity and also in ordinary wood biomass through biosorption. The Pb(II)-impregnated biomass was then pretreated with phosphoric acid or calcium dihydrogen phosphate (CaP) and pyrolyzed at 350 or 450°C. Pb(II) from biomass was in turn almost totally retained in chars, and the percentage of DTPA-extractable Pb(II) was reduced to less than 5% of total Pb(II) in chars through CaP pretreatment. Pb(II) stabilization was further confirmed through a sequential extraction test, which showed that more than 95% of Pb(II) was converted into stable species composed mainly of lead phosphates according to X-ray diffraction (XRD) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analyses. Overall, phosphate-pretreated pyrolysis can stabilize both Pb(II) and degradable biomass, so as to control efficiently the hazards of heavy metal-contaminated biomass.
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
authors.forename: Saijun
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhang
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China. Electronic address: ljf@usx.edu.cn.
authors.forename: Jianfa
authors.initials: J
authors.lastname: Li
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
authors.forename: Lingna
authors.initials: L
authors.lastname: Shi
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: Zhu
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
authors.forename: Jinhong
authors.initials: J
authors.lastname: Lü
authors.affiliation: College of Chemistry & Chemical Engineering, Shaoxing University, Shaoxing, Zhejiang, 312000, China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Li
mesh_terms: D000327:Adsorption; D000077102:Apium / Q000737:chemistry; D018533:Biomass; D002606:Charcoal / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis*; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006358:Hot Temperature; D007854:Lead / Q000032:analysis*; D008962:Models, Theoretical; D010710:Phosphates / Q000737:chemistry*; D014934:Wood / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D010710:Phosphates; C540010:biochar; D002606:Charcoal; D007854:Lead
keywords: Biomass; Biosorption; Heavy metal; Immobilization; Pyrolysis