Title: Effect of moisture content on microwave-assisted extraction of PCBs and chlorobenzenes

Authors: Yifei Sun; Masaki Takaoka; Yadi Zhang; Wei Wang

Addresses: School of Space and Environment, Beihang University, Haidian District, 100191, Beijing, China ' Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, C-kluster, Kyotodaigaku-Katsura, Nishikyo-ku, 615-8540, Kyoto, Japan ' School of Chemistry and Environment, Beihang University, Haidian District, 100191, Beijing, China ' School of Environment, Tsinghua University, Haidian District, 100084, Beijing, China

Abstract: Polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs) generated during municipal solid waste incineration (MSWI) pose a great threat to both human health and the environment. In the present study, an application of microwave-assisted extraction (MAE) is introduced to extract PCBs and CBzs from actual fly ash and sludge. The effect of moisture content on the extraction efficiency of MAE has been investigated and compared with that of conventional soxhlet extraction (SE). Lower moisture content leads to higher extraction efficiency. When adding Na₂SO₄ to absorb the residual moisture from sludge, the recorded concentration of PCBs and CBzs reaches its maximum value. Compared to SE, MAE shows unique advantages: high extraction efficiency for chlorinated homologues, shorter extraction time and less solvent volume spent.

Keywords: microwave-assisted extraction; MAE; moisture content; extraction efficiency; polychlorinated biphenyls; PCBs; chlorobenzenes; CBzs; fly ash; sludge; municipal solid waste incineration; MSWI.

DOI: 10.1504/IJEP.2017.085661

International Journal of Environment and Pollution, 2017 Vol.61 No.2, pp.148 - 165

Received: 24 Dec 2016
Accepted: 22 Feb 2017
Published online: 05 Aug 2017 *

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