Abstract The transformation of mercury fractions under both natural environmental conditions and ultraviolet irradiation (UV) conditions was studied in this work. Mercury in desulfurization gypsum was divided into five fractions by sequential extraction procedure depending on its bioavailability. The five fractions were named as water soluble fraction (F1), ion-exchangeable fraction (F2), acid soluble fraction (F3), elemental fraction (F4), and sulfide fraction (F5). The results from our study demonstrated that the proportion of different fraction was in the following order: elemental fraction > water soluble fraction > acid soluble fraction > ion-exchangeable fraction > sulfide fraction. The results indicated that mercury could be released from desulfurization gypsum during aging process and the release process could be promoted via ultraviolet irradiation. The release amount increased with the irradiation time and intensity (up to 25.1% of the total initial amount). The percentage of mercury in F1 decreased gradually with aging time, while the percentage of mercury in elemental and residual fractions increased gradually. Our research will be helpful for the survey and understand of mercury emission from desulfurization gypsum.

中文翻译：

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脱硫石膏老化过程中的汞释放和馏分转化（紫外线照射）

摘要 本工作研究了在自然环境条件和紫外线照射 (UV) 条件下汞组分的转化。脱硫石膏中的汞根据其生物利用度通过顺序提取程序分为五个部分。这五个级分分别命名为水溶性级分（F1）、离子交换级分（F2）、酸溶性级分（F3）、元素级分（F4）和硫化物级分（F5）。我们的研究结果表明，不同组分的比例依次为：元素组分>水溶性组分>酸溶组分>离子交换组分>硫化物组分。结果表明，脱硫石膏在老化过程中会释放汞，紫外线照射可以促进汞的释放。释放量随着照射时间和强度的增加而增加（高达初始总量的 25.1%）。F1中汞的百分比随着老化时间逐渐减少，而元素和残余部分中的汞百分比逐渐增加。我们的研究将有助于对脱硫石膏汞排放的调查和了解。