State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing, 100085, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
International Environmental Cooperation Center, Ministry of Ecology and Environment of People's Republic of China, Beijing, 100035, China.
Environ Pollut. 2020 May;260:113946. doi: 10.1016/j.envpol.2020.113946. Epub 2020 Jan 14.
Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are cancerogenic organic pollutants that priority controlled by Stockholm Convention with globally 183 signatories now. Secondary nonferrous smelting plants are confirmed to be important sources in China due to its large industrial activities and high emissions of PCDD/Fs. It is important to prioritize source to achieve source emission reduction by conducting field monitoring on typical case plants. Here, the emission profiles and levels of PCDD/Fs were investigated in 25 stack gas samples collected from three secondary copper production (SeCu), two secondary zinc production (SeZn) and two secondary lead production (SePb). Both average mass concentration and toxic equivalency quantity (TEQ) concentrations of PCDD/Fs all generally decreased in the order: SeCu > SeZn > SePb. It is noteworthy that the mean TEQ concentration in stack gas from SeCu with oxygen-enrich melting furnace technology, at 2.7 ng I-TEQ/Nm, was much higher than the concentrations of other smelting processes. The average emission factors and annual release amounts of PCDD/Fs from SeCu, SePb and SeZn investigated were 28.4, 1.5, 10.4 μg I-TEQ/t and 1.03, 0.023, 0.17 g I-TEQ/year, respectively. The ratios of 2,3,7,8-TCDF to 1,2,3,7,8-PeCDF and OCDD to 1,2,3,7,8,9-HxCDD varied to large extent for three metal smelting, which could be used as diagnostic ratios of tracing specific PCDD/Fs sources. Addition of copper-containing sludge into the raw materials might lead to higher PCDD/Fs emissions. It is important to emphasize and reduce the PCDD/Fs emissions from oxygen-enrich melting furnace from secondary copper productions.
多氯二苯并对二恶英和多氯二苯并呋喃（PCDD/Fs）是具有致癌性的有机污染物，已被《斯德哥尔摩公约》列为优先控制污染物，目前该公约的签署国已达 183 个。由于工业活动量大、排放的 PCDD/Fs 多，中国的二次有色金属冶炼厂已被确认为此类污染物的重要排放源。通过对典型案例工厂进行现场监测，确定排放源并实现源头减排非常重要。本研究采集了 3 家铜二次冶炼厂（SeCu）、2 家锌二次冶炼厂（SeZn）和 2 家铅二次冶炼厂（SePb）的 25 个烟道气样本，调查了 PCDD/Fs 的排放特征和水平。PCDD/Fs 的质量浓度和毒性当量浓度（TEQ）平均值均呈现出 SeCu>SeZn>SePb 的趋势。值得注意的是，采用富氧熔池熔炼技术的铜二次冶炼厂烟道气中的 TEQ 浓度均值（2.7 ng I-TEQ/Nm）明显高于其他冶炼工艺。本研究调查的铜、铅和锌二次冶炼厂的 PCDD/Fs 排放因子和年排放量分别为 28.4、1.5、10.4 μg I-TEQ/t 和 1.03、0.023、0.17 g I-TEQ/年。3 种金属冶炼中二噁英的 2,3,7,8-TCDF 与 1,2,3,7,8-PeCDF 比值和 OCDD 与 1,2,3,7,8,9-HxCDD 比值变化范围较大，可作为追踪特定 PCDD/Fs 排放源的示踪诊断比。在原料中添加含铜污泥可能会导致更高的 PCDD/Fs 排放量。因此，有必要强调并减少二次铜生产中富氧熔炼炉的 PCDD/Fs 排放。
