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
| Autor: | Zenghui Diao, Jian-Jun Du, Cui-Mei Liu, Lingjun Kong, Qihang Wu, Xiang-Rong Xu, Dan Jiang, Wen-Yi Huo |
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| Rok vydání: | 2018 |
| Předmět: |
Pollutant
021110 strategic defence & security studies Zerovalent iron Environmental Engineering Environmental remediation Inorganic chemistry 0211 other engineering and technologies 02 engineering and technology 010501 environmental sciences Phosphate 01 natural sciences Pollution chemistry.chemical_compound Adsorption chemistry Biochar Environmental Chemistry Leaching (metallurgy) Malachite green Waste Management and Disposal 0105 earth and related environmental sciences |
| Zdroj: | Science of The Total Environment. 642:505-515 |
| ISSN: | 0048-9697 |
| Popis: | 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 30 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. |
| Databáze: | OpenAIRE |
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