Institute of Lake Environment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
Environ Sci Pollut Res Int. 2014 May;21(10):6463-71. doi: 10.1007/s11356-013-2480-5. Epub 2014 Feb 7.
In this study, the 30-day aerobic microorganism-mediated biodegradation of polycyclic aromatic hydrocarbons (PAHs) was investigated in four size fractions (i.e., <0.002, 0.002-0.031, 0.031-0.063 and >0.063 mm) of sand-dominated sediment S1 and mud-dominated S2 collected from intertidal zones in Bohai Bay (China). Prior to biodegradation, the total quantity of phenanthrene, fluoranthene and pyrene comprised more than 80% of the total quantity of 16 EPA-priority PAHs in each size fraction, with the exception of 70.33% found in the >0.063 mm fraction of sediment S1. Among the three dominant compounds, the intermediate size fraction (0.031-0.063 mm) showed higher levels of biodegradation than other size fractions in sediment S1 and S2. After pooling data from sediment S1 and S2 for joint analysis, it was observed that the biodegraded portion of the three dominant compounds showed negative correlations with both total organic carbon (TOC) and humic coverage index (HCI) in the size fractions. The observed negative correlation with TOC was in agreement with findings in many other studies, but the negative correlation with HCI had not been observed in early studies, which only investigated aged sediment/soil samples. The findings in this study indicated that the greatest bioavailability of PAHs in intertidal surface sediment may be present in sediment particles of intermediate size and mobility, and that intertidal sediment particles are less likely to experience sufficient ageing given periodical tidal disturbance. These findings have important implications for the assessment of the environmental fate of PAHs in intertidal regions.
本研究调查了在中国渤海湾潮间带采集的以砂为主的沉积物 S1 和以泥为主的沉积物 S2 的四个粒径（<0.002、0.002-0.031、0.031-0.063 和>0.063 mm）中，30 天内好氧微生物介导的多环芳烃（PAHs）生物降解作用。在生物降解之前，每个粒径中，16 种美国环保署优先控制的 PAHs 总量中，菲、荧蒽和芘的总量占 80%以上，除了 S1 中>0.063mm 粒径的部分为 70.33%。在这三种主要化合物中，中间粒径（0.031-0.063mm）在 S1 和 S2 沉积物中的生物降解程度高于其他粒径。将 S1 和 S2 沉积物的数据合并进行联合分析后，发现三种主要化合物中被生物降解的部分与粒径中的总有机碳（TOC）和腐殖质覆盖指数（HCI）均呈负相关。与 TOC 的负相关与许多其他研究的结果一致，但与 HCI 的负相关在早期研究中没有观察到，早期研究仅调查了老化的沉积物/土壤样品。本研究的结果表明，潮间带表层沉积物中 PAHs 的最大生物可利用性可能存在于中等大小和流动性的沉积物颗粒中，并且由于定期的潮汐干扰，潮间带沉积物颗粒不太可能经历足够的老化。这些发现对评估潮间带地区 PAHs 的环境归宿具有重要意义。
