Nutrition and Bromatology Group, Analytical and Food Chemistry Department, Faculty of Food Science and Technology, University of Vigo Ourense Campus, Ourense, Spain.
Environ Sci Pollut Res Int. 2011 Aug;18(7):1139-46. doi: 10.1007/s11356-011-0467-7. Epub 2011 Feb 19.
Solid waste incineration has recently attracted much attention because the combustion process involved produces highly toxic organohalogen contaminants such as dioxin-like polychlorinated biphenyls (DL-PCBs) present in fly ash. This has raised the need for simple, rapid, accurate methods for monitoring PCBs in ash samples.
A method for the simultaneous quantitative determination of indicator, non-ortho and mono-ortho PCBs based on ultrasound-assisted extraction with 50:50 (v/v) n-hexane/acetone was developed, validated, and subsequently applied to real samples from a mussel shell incinerator facility in Galicia. The overall method quantification limits range from 0.35 to 1.5 ng/g in fly ash waste, from 0.30 to 1.0 ng/g in bottom ashes, and from 1.0 to 2.0 ng/g in sludge samples. Mean recoveries between 70% and 105% are achieved.
DL-PCBs were identified in ash and in sludge samples collected from the wastewater treatment plant of the waste incineration facility. The enrichment factors for fly ash ranged from 3.3 to 3.7. Sewage sludge was also found to contain some polychlorinated biphenyls such as PCB 77 (29 ± 5.0 ng/g; n=4) and PCB 169 (6.9 ± 0.89 ng/g; n=4), as well as three of the seven PCB-like indicators, namely: PCB 138 (14 ± 4.4 ng/g), PCB 153 (6.1 ± 1.4 ng/g), and PCB 180 (7.7 ± 3.0 ng/g). Toxicity equivalent concentrations were 0.0054 ng/g for bottom ash, 0.0264 ng/g for fly ash, and 3.6 ng/g for sewage sludge; these values are well below the limit for DL-PCBs in wastes recently set by the European Union.
All samples studied contained PCBs at levels below the maximum tolerated limit established by European legislation. Based on their PCB content, the studied sewage sludge can be used as a soil amendment with no health risk. Also, fly ash and sewage sludge can be deemed stable PCB reservoirs releasing PCBs at concentrations below the regulatory cutoff to runoff water.
由于燃烧过程中会产生高度有毒的有机卤代污染物，如二恶英类多氯联苯（DL-PCBs），存在于飞灰中，因此固体废物焚烧最近引起了广泛关注。这就需要开发简单、快速、准确的监测灰分中 PCBs 的方法。
建立了一种基于超声辅助提取的 50:50（v/v）正己烷/丙酮同时定量测定指示、非邻位和单邻位 PCBs 的方法，对加利西亚贻贝壳焚烧设施的实际样品进行了验证，并随后应用于实际样品。在飞灰废物中，总方法定量限范围为 0.35 至 1.5ng/g，在底灰中为 0.30 至 1.0ng/g，在污泥样品中为 1.0 至 2.0ng/g。回收率在 70%至 105%之间。
在焚烧设施废水处理厂收集的灰分和污泥样品中鉴定出 DL-PCBs。飞灰的富集因子范围为 3.3 至 3.7。污水污泥中还含有一些多氯联苯，如 PCB 77（29±5.0ng/g；n=4）和 PCB 169（6.9±0.89ng/g；n=4），以及七种 PCB 类似物指标中的三种，即：PCB 138（14±4.4ng/g）、PCB 153（6.1±1.4ng/g）和 PCB 180（7.7±3.0ng/g）。底灰的毒性当量浓度为 0.0054ng/g，飞灰为 0.0264ng/g，污水污泥为 3.6ng/g；这些值远低于欧盟最近为 DL-PCBs 设定的废物限量。
所有研究样品中的 PCBs 含量均低于欧洲法规规定的最大允许限量。根据其 PCB 含量，研究中的污水污泥可用作土壤改良剂，不会带来健康风险。此外，飞灰和污水污泥可被视为稳定的 PCB 储存库，向径流水中释放的 PCBs 浓度低于监管截止值。
