Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism
Nanoscale zero-valent iron (nZVI) and sulfides have been confirmed to be effective in arsenic sequestration from aqueous solution. In this study, attapulgite supported and sulfide-modified nanoscale zero-valent iron (S-nZVI@ATP) are synthesized to realize the superposition effect of enhanced arsenic...
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| Format: | Article |
| Language: | English |
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IWA Publishing
2021-06-01
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| Series: | Water Science and Technology |
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| Online Access: | http://wst.iwaponline.com/content/83/12/2886 |
| _version_ | 1818751501829406720 |
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| author | Shun Cheng Hong Liu Emmanuella Anang Chunxia Li Xianyuan Fan |
| author_facet | Shun Cheng Hong Liu Emmanuella Anang Chunxia Li Xianyuan Fan |
| author_sort | Shun Cheng |
| collection | DOAJ |
| description | Nanoscale zero-valent iron (nZVI) and sulfides have been confirmed to be effective in arsenic sequestration from aqueous solution. In this study, attapulgite supported and sulfide-modified nanoscale zero-valent iron (S-nZVI@ATP) are synthesized to realize the superposition effect of enhanced arsenic sequestration. The results indicated that nZVI clusters were well disaggregated and the BET specific surface area increased from 19.61 m2·g−1 to 46.04 m2·g−1 of S-nZVI@ATP, resulting in an enhanced removal efficiency of arsenic from 51.4% to 65.1% at 20 min. The sulfides in S-nZVI@ATP mainly exist as mackinawite (FeS) and this causes the spherical nanoparticles to exhibit a larger average particle size (94.6 nm) compared to bare nZVI (66.0 nm). In addition, S-nZVI@ATP exhibited a prominent ability for arsenic sequestration over a wide pH range of 3.0–6.0. The presence of anions SO42− and Cl− can enhance the arsenic removal whereas HCO3− inhibited it. The arsenic adsorption by S-nZVI@ATP could be explained by the pseudo-second-order kinetic model and the Langmuir model, with the maximum adsorption capacity of 193.8 mg·g−1. The mechanism of As(III) sequestration by S-nZVI@ATP involved multiple processes, mainly including precipitation conversion from FeS to As2S3, surface-complexation adsorption and co-precipitation. HIGHLIGHTS
S-nZVI@ATP was synthesized to superimpose the performance of nZVI and sulfides on arsenic removal.;
The distribution of sulfides in S-nZVI@ATP and its role for As(III) removal were investigated.;
S-nZVI@ATP showed an enlarged specific surface area and an enhanced arsenic removal efficiency.;
The maximum adsorption capacity for arsenic was 193.8 mg·g−1.;
The mechanism involved the combined action of Fe(0) core and sulfide shell.; |
| first_indexed | 2024-12-18T04:36:35Z |
| format | Article |
| id | doaj.art-93b6e4fd2854481fb915b18a9148e550 |
| institution | Directory Open Access Journal |
| issn | 0273-1223 1996-9732 |
| language | English |
| last_indexed | 2024-12-18T04:36:35Z |
| publishDate | 2021-06-01 |
| publisher | IWA Publishing |
| record_format | Article |
| series | Water Science and Technology |
| spelling | doaj.art-93b6e4fd2854481fb915b18a9148e5502022-12-21T21:20:50ZengIWA PublishingWater Science and Technology0273-12231996-97322021-06-0183122886290010.2166/wst.2021.184184Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanismShun Cheng0Hong Liu1Emmanuella Anang2Chunxia Li3Xianyuan Fan4 College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China and Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan University of Science and Technology, Wuhan 430081, China College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China and Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan University of Science and Technology, Wuhan 430081, China College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China and Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan University of Science and Technology, Wuhan 430081, China Research Institute for Environmental Innovation (Suzhou), Tsinghua, Suzhou 215011, China College of Resource and Environmental Engineering, Wuhan University of Science and Technology, Wuhan 430081, China and Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources, Wuhan University of Science and Technology, Wuhan 430081, China Nanoscale zero-valent iron (nZVI) and sulfides have been confirmed to be effective in arsenic sequestration from aqueous solution. In this study, attapulgite supported and sulfide-modified nanoscale zero-valent iron (S-nZVI@ATP) are synthesized to realize the superposition effect of enhanced arsenic sequestration. The results indicated that nZVI clusters were well disaggregated and the BET specific surface area increased from 19.61 m2·g−1 to 46.04 m2·g−1 of S-nZVI@ATP, resulting in an enhanced removal efficiency of arsenic from 51.4% to 65.1% at 20 min. The sulfides in S-nZVI@ATP mainly exist as mackinawite (FeS) and this causes the spherical nanoparticles to exhibit a larger average particle size (94.6 nm) compared to bare nZVI (66.0 nm). In addition, S-nZVI@ATP exhibited a prominent ability for arsenic sequestration over a wide pH range of 3.0–6.0. The presence of anions SO42− and Cl− can enhance the arsenic removal whereas HCO3− inhibited it. The arsenic adsorption by S-nZVI@ATP could be explained by the pseudo-second-order kinetic model and the Langmuir model, with the maximum adsorption capacity of 193.8 mg·g−1. The mechanism of As(III) sequestration by S-nZVI@ATP involved multiple processes, mainly including precipitation conversion from FeS to As2S3, surface-complexation adsorption and co-precipitation. HIGHLIGHTS S-nZVI@ATP was synthesized to superimpose the performance of nZVI and sulfides on arsenic removal.; The distribution of sulfides in S-nZVI@ATP and its role for As(III) removal were investigated.; S-nZVI@ATP showed an enlarged specific surface area and an enhanced arsenic removal efficiency.; The maximum adsorption capacity for arsenic was 193.8 mg·g−1.; The mechanism involved the combined action of Fe(0) core and sulfide shell.;http://wst.iwaponline.com/content/83/12/2886as(iii) sequestrationattapulgitenanoscale zero-valent ironremoval mechanismsulfidation |
| spellingShingle | Shun Cheng Hong Liu Emmanuella Anang Chunxia Li Xianyuan Fan Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism Water Science and Technology as(iii) sequestration attapulgite nanoscale zero-valent iron removal mechanism sulfidation |
| title | Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism |
| title_full | Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism |
| title_fullStr | Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism |
| title_full_unstemmed | Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism |
| title_short | Enhanced As(III) sequestration using nanoscale zero-valent iron modified by combination of loading and sulfidation: characterizations, performance, kinetics and mechanism |
| title_sort | enhanced as iii sequestration using nanoscale zero valent iron modified by combination of loading and sulfidation characterizations performance kinetics and mechanism |
| topic | as(iii) sequestration attapulgite nanoscale zero-valent iron removal mechanism sulfidation |
| url | http://wst.iwaponline.com/content/83/12/2886 |
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