Magnetite impregnation effects on the sorbent properties of activated carbons and biochars

WATER RESEARCH

卷:70

Article

Han, Zhantao^1,2,3  Sani, Badruddeen¹  Mrozik, Wojciech^1,4  Obst, Martin⁵  Beckingham, Barbara^5,6  Karapanagioti, Hrissi K.⁷  Werner, David¹ 

[1] Newcastle Univ, Sch Civil Engn & Geosci, Newcastle Upon Tyne NE1 7RU, Tyne & Wear, England

[2] Chinese Acad Geol Sci, Inst Hydrogeol & Environm Geol, Shijiazhuang 050061, Peoples R China

[3] Hebei Key Lab Groundwater Remediat, Shijiazhuang 050061, Peoples R China

[4] Med Univ Gdansk, Dept Inorgan Chem, PL-80210 Gdansk, Poland

[5] Univ Tubingen, Ctr Appl Geosci, Dept Geosci, D-72074 Tubingen, Germany

[6] Coll Charleston, Dept Geol & Environm Geosci, Charleston, SC 29401 USA

[7] Univ Patras, Dept Chem, Patras 26504, Greece

关键词: Magnetic sorbents;    Activated carbon;    Biochar;    Wastewater treatment;    Soil and sediment remediation;   

DOI  :  10.1016/j.watres.2014.12.016

来源: Elsevier

【 摘 要 】

This paper discusses the sorbent properties of magnetic activated carbons and biochars produced by wet impregnation with iron oxides. The sorbents had magnetic susceptibilities consistent with theoretical predictions for carbon-magnetite composites. The high BET surface areas of the activated carbons were preserved in the synthesis, and enhanced for one low surface area biochar by dissolving carbonates. Magnetization decreased the point of zero charge. Organic compound sorption correlated strongly with BET surface areas for the pristine and magnetized materials, while metal cation sorption did not show such a correlation. Strong sorption of the hydrophobic organic contaminant phenanthrene to the activated carbon or biochar surfaces was maintained following magnetite impregnation, while phenol sorption was diminished, probably due to enhanced carbon oxidation. Copper, zinc and lead sorption to the activated carbons and biochars was unchanged or slightly enhanced by the magnetization, and iron oxides also contributed to the composite metal sorption capacity. While a magnetic biochar with 219 +/- 3.7 m(2)/g surface area nearly reached the very strong organic pollutant binding capacity of the two magnetic activated carbons, a magnetic biochar with 68 +/- 2.8 m(2)/g surface area was the best metal sorbent. Magnetic biochars thus hold promise as more sustainable alternatives to coal-derived magnetic activated carbons. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

Free