Sediment quality assessment in a coastal lagoon (Ravenna, NE Italy) based on SEM-AVS and sequential extraction procedure.
Sediment quality assessment in a coastal lagoon (Ravenna, NE Italy) based on SEM-AVS and sequential extraction procedure.
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DOI：
10.1016/j.scitotenv.2018.04.093
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
Emanuela Pignotti;R. Guerra;S. Covelli;E. Fabbri;E. Dinelli
中科院分区：
文献类型：
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作者：
Emanuela Pignotti;R. Guerra;S. Covelli;E. Fabbri;E. Dinelli
从Pialassa Piomboni沿海泻湖（NE意大利）的沉积物进行了研究，以评估的污染程度和生态风险相结合的痕量金属的生物可利用形式的评估散装沉积物的地球化学表征。有了这个目的，沉积物污染（镉，铜，汞，镍，铅，锌）进行了评估富集因子（EFs），和潜在的生物利用度的同时提取的金属和酸挥发性硫化物（SEM-AVS）的方法（镉，铜，镍，铅，锌），并通过顺序提取程序（钴，铬，铜，镍，铅，锌）。平均而言，铬和镍没有显示出污染（EF ≤1.5），并在沉积物的残留部分占主导地位，表明这些金属的自然来源。Cu、Pb和Zn显示出局部污染，这导致Cu结合到可还原和可氧化部分的比例较高（中位数分别为~30%和~40%），Pb主要与可还原相结合（中位数为~60%）。因此，当环境条件变得还原或氧化时，Cu和Pb可以被活化。Zn主要分配到可还原和残留馏分中（两种馏分中的中位数约为50%）。风险评估代码（RAC）表明，约30%的样品中有>10%的总锌与沉积物弱结合，这表明水生生物的中等暴露风险。RAC结果与∑SEM-AVS结果一致，表明约30%的样品可能对水生生物群产生不利影响，锌主要占总金属生物利用度。汞显示出中度到非常严重的富集，表明这种金属的大量来源于人为来源，可能对皮亚拉萨皮翁博尼泻湖的水生生物群造成不利影响。
Sediments from the Pialassa Piomboni coastal lagoon (NE Italy) were studied to assess the degree of contamination and ecological risk related to trace metals by combining a geochemical characterization of bulk sediments with the assessment of the bioavailable forms of trace metals. With this purpose, sediment contamination (Cd, Cu, Hg, Ni, Pb, and Zn) was assessed by Enrichment Factors (EFs), and potential bioavailability by the Simultaneously Extracted Metals and Acid Volatile Sulfides (SEM-AVS) approach (Cd, Cu, Ni, Pb, and Zn), and by Sequential Extraction Procedure (Co, Cr, Cu, Ni, Pb, and Zn). On average, Cr and Ni exhibited no contamination (EF ≤1.5), and a predominance in the residual fraction of the sediment, indicating natural origin for these metals. Cu, Pb and Zn displayed a local contamination, which resulted in a higher proportion of Cu bound to the reducible and oxidizable fractions (~30% and ~40% as median, respectively), and Pb mostly associated with the reducible phase (~60% as median). Hence, Cu and Pb could be mobilized when environmental conditions become reducing or oxidizing. Zn resulted mainly partitioned into the reducible and residual fractions (~50% as median, in both fractions). The Risk Assessment Code (RAC) indicated that approximately 30% of samples had >10% of total Zn weakly bound to the sediment, suggesting a medium risk of exposure for aquatic organisms. RAC results were consistent with the ∑SEM-AVS findings, pointing to possible adverse effects for aquatic biota in ~30% of samples, with Zn mostly accounting for the total metal bioavailability. Hg showed a moderate to very severe enrichment, indicating that a substantial amount of this metal derives from anthropogenic sources and may pose adverse effects on the aquatic biota of the Pialassa Piomboni lagoon.