Evaluation of dioxins and dioxin-like compounds from a cement plant using carbide slag from chlor-alkali industry as the major raw material

Yuyang Zhao; Jiayu Zhan; Guorui Liu; Minghui Zheng; Rong Jin; Lili Yang; Liwei Hao; Xiaolin Wu; Xian Zhang; Pu Wang

doi:10.1016/j.jhazmat.2017.02.018

Evaluation of dioxins and dioxin-like compounds from a cement plant using carbide slag from chlor-alkali industry as the major raw material

J Hazard Mater. 2017 May 15:330:135-141. doi: 10.1016/j.jhazmat.2017.02.018. Epub 2017 Feb 14.

Authors

Yuyang Zhao¹, Jiayu Zhan², Guorui Liu³, Minghui Zheng¹, Rong Jin¹, Lili Yang¹, Liwei Hao², Xiaolin Wu¹, Xian Zhang¹, Pu Wang¹

Affiliations

¹ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² State Key Laboratory of Solid Waste Reuse for Building Materials, Beijing Building Materials Academy of Sciences Research, Beijing 100041, China.
³ State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: grliu@rcees.ac.cn.

PMID: 28214649
DOI: 10.1016/j.jhazmat.2017.02.018

Abstract

Carbide slag produced from chlor-alkali industry contains high amounts of calcium compounds and can potentially be used as raw material for cement production; however, it contains large amounts of chlorine so it is essential to evaluate the emissions of chlorinated organic pollutants, including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polychlorinated naphthalenes (PCNs). A field study of the emission profiles of these pollutants in a cement plant using such slag was performed. The average concentrations of PCDD/Fs, PCBs, and PCNs in stack gases collected at the kiln back end were 6.31, 1.07, and 31.89pg TEQ m^-3, respectively. PCDFs dominated over PCDDs in particulate samples. Di- to pentachlorinated biphenyls were dominant homologs in the particulate samples. MonoCBs were the dominant homolog in stack gases from the kiln back end, and homolog concentrations decreased with increasing chlorine numbers. Mono- and diCNs accounted for 48-98% of PCNs. The estimated toxic equivalents of stack gas emissions of PCNs, classified as new persistent organic pollutants under Stockholm Convention, were unexpectedly higher than those of PCDD/Fs and PCBs. A mass balance indicated that all of the toxic equivalents were reduced by this cement kiln system. The highest 2,3,7,8-PCDD/F output is with clinker.

Keywords: Carbide slag; Cement; Dioxin; Polychlorinated biphenyl; Polychlorinated naphthalene.