Department of Civil and Environmental Engineering, Maroun Semaan Faculty of Engineering and Architecture, American University of Beirut, P.O.Box: 11-0236, Riad El Solh, 1107 2020 Beirut, Lebanon.
Department of Civil and Environmental Engineering, Maroun Semaan Faculty of Engineering and Architecture, American University of Beirut, P.O.Box: 11-0236, Riad El Solh, 1107 2020 Beirut, Lebanon.
Sci Total Environ. 2019 Apr 10;660:227-235. doi: 10.1016/j.scitotenv.2019.01.025. Epub 2019 Jan 4.
With the planned oil and gas exploration activities off the coast of Lebanon, the risk of shoreline contamination with crude oil spills has become a major concern. This study aimed at assessing the crude oil bioremediation potential of the chronically polluted Lebanese shores in light of the continuous discharge of nutrient-rich sewage into the Mediterranean Sea and the long-lasting absence of proper sewage treatment systems. It was anticipated that, with the high pollution levels of the coastline, background concentrations of nutrients would be sufficient to sustain high intrinsic biodegradation rates without human intervention. Biodegradation experiments were conducted using crude oil-spiked beach sediments and seawater under natural attenuation and biostimulation conditions. The experiments were conducted at 18 and 28 °C to account for seasonal variation in temperature, background nutrient levels, and microbial communities. The biodegradability of oil constituents - namely alkanes and polycyclic aromatic hydrocarbons (PAHs), was monitored over a 42-day period using gas chromatography-mass spectrometry (GC-MS). Under biostimulation conditions, significant enhancement in the overall biodegradation rates of alkanes and PAHs was observed in seawater at 18 and 28 °C, while little to no improvement was measured at both temperatures in sediments where background nutrient levels were sufficient to induce near maximum intrinsic biodegradation rates. Under both natural attenuation and biostimulation treatments, the increase in temperature increased the oil biodegradation rates in sediment and seawater microcosms. In both instances, the overall trend in the biodegradation of individual alkanes and PAHs suggested a typical decrease in biodegradation rates with the increase in carbon number/rings and alkyl groups.
随着黎巴嫩沿海计划中的石油和天然气勘探活动，海岸线受到原油泄漏污染的风险已成为一个主要关注点。本研究旨在评估黎巴嫩受污染海岸线的原油生物修复潜力，因为营养丰富的污水不断排入地中海，且长期缺乏适当的污水处理系统。据预测，由于海岸线污染水平高，背景营养物浓度足以维持高固有生物降解率，而无需人为干预。在自然衰减和生物刺激条件下，使用原油污染海滩沉积物和海水进行了生物降解实验。实验在 18 和 28°C 下进行，以考虑温度、背景营养物水平和微生物群落的季节性变化。使用气相色谱-质谱联用仪 (GC-MS) 在 42 天的时间内监测油成分（即烷烃和多环芳烃 (PAH)）的生物降解性。在生物刺激条件下，在 18 和 28°C 下，海水中烷烃和 PAH 的整体生物降解率显著提高，而在沉积物中，由于背景营养物水平足以诱导接近最大固有生物降解率，因此在这两个温度下几乎没有改善。在自然衰减和生物刺激处理下，温度升高均增加了沉积物和海水微宇宙中的油生物降解率。在这两种情况下，单个烷烃和 PAH 的生物降解总体趋势表明，生物降解率随碳数/环数和烷基基团的增加而典型降低。
