Insights into the simultaneous removal of Cr6+ and Pb2+ by a novel sewage sludge-derived biochar immobilized nanoscale zero valent iron: Coexistence effect and mechanism.
Sci Total Environ
; 642: 505-515, 2018 Nov 15.
Article
em En
| MEDLINE
| ID: mdl-29908509
ABSTRACT
Cr6+ and Pb2+ are both highly toxic pollutants and commonly co-exist in some industrial effluents and contaminated waters. In this study, simultaneous removal of Cr6+ and Pb2+ by a novel sewage sludge-derived biochar immobilized nanoscale zero-valent iron (SSB-nZVI) was systematically investigated. It was well demonstrated that a porous structure was successfully formed on the SSB-nZVI when the starch was used as an additive. A synergistic effect on the adsorption and reduction over the SSB-nZVI was achieved, resulting in nearly 90 and 82% of Cr6+ and Pb2+ removal within 30â¯min, respectively. Cr6+ was reduced prior to Pb2+. A low pH could accelerate the corrosion of nZVI as well as phosphate leaching. When Malachite green was added as a coexisting organic pollutant, its effective removal was found due to the formation of a Fenton-like system. The SSB-nZVI could be run consecutively three times with a relatively satisfactory performance. Most of Cr6+ was converted into Cr2O3 and Cr(OH)3 on the SSB-nZVI surface, whereas most of Pb2+ species existed as Pb(OH)2 (or PbO). A possible reaction mechanism on the SSB-nZVI involved the adsorption, reduction and precipitation of both Cr6+ and Pb2+ over the particles. Present study sheds light on the insight of the fate and transport of Cr6+ and Pb2+ in aquatic environment, as well provides helpful guide for the remediation of coexistence of pollutants in real applications.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
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Eliminação de Resíduos Líquidos
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Cromo
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Ferro
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Chumbo
Idioma:
En
Revista:
Sci Total Environ
Ano de publicação:
2018
Tipo de documento:
Article