Sanchez-Huerta Claudia, Zhang Shuo, Alahmari Manar, Humam Abdulmohsen A, Hong Pei-Ying
Environmental Science and Engineering Program, Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Kingdom of Saudi Arabia.
Saudi Aramco EXPEC Advanced Research Center (EXPEC ARC), Dhahran, 31311, Kingdom of Saudi Arabia.
Chemosphere. 2025 May;376:144290. doi: 10.1016/j.chemosphere.2025.144290. Epub 2025 Mar 14.
Remediation of hydrocarbon-contaminated groundwater is challenging due to the large volume of contaminated water, restricted aquifer access, and the recalcitrance of hydrocarbons. This study evaluates chemically-based surfactants (A and B, comprised of alcohols, esters and distillates from petroleum) and biosurfactants (C and BS, containing enzymes and microbial-derived surfactants) to enhance petroleum-hydrocarbon remediation. Surfactants/biosurfactants were evaluated under environmental conditions mimicking Arabic Region groundwater. The influence of factors like surfactant to crude oil ratios (S:O), temperature, and dissolved oxygen on the remediation performance was analyzed. Among studied surfactants, C and BS demonstrated the best performance. Multi-spike of C achieved the highest reduction of crude oil layer thickness (41.9%) and total petroleum-hydrocarbons (TPH) removal (20.6%). However, since dispersion mechanisms drove removal, it led to increased turbidity (3.5 NTU) and toxicity (61.6% biofluorescence-inhibition) in the water phase. In contrast, BS with a similar performance in terms of crude oil layer reduction (38.5%) and TPH removal (17.8%) resulted in lower levels of turbidity (1.8 NTU) and toxicity (26.8% biofluorescence-inhibition). This is attributed to the removal via both dispersion and biodegradation. BS-biodegradation was associated to a high relative abundance of Pseudomonas spp. with abilities to degrade low molecular and polyaromatic hydrocarbons (i.e., BTEX and PAHs). Results demonstrated BS is the most sustainable product to enhance hydrocarbons removal. Significant influence in the remediation process was observed at optimal S:O ratio (C-1:5 BS-1:10) and high temperature of 35 °C. Our findings elucidated the mechanisms involved in groundwater remediation via surfactants/biosurfactants, and provide optimal parameters for its application in-situ.
由于受污染水体量大、含水层进入受限以及碳氢化合物的难降解性，修复受碳氢化合物污染的地下水具有挑战性。本研究评估了基于化学的表面活性剂（A和B，由醇类、酯类和石油馏出物组成）和生物表面活性剂（C和BS，含有酶和微生物衍生的表面活性剂）对石油碳氢化合物修复的促进作用。在模拟阿拉伯地区地下水的环境条件下对表面活性剂/生物表面活性剂进行了评估。分析了表面活性剂与原油比例（S:O）、温度和溶解氧等因素对修复性能的影响。在所研究的表面活性剂中，C和BS表现出最佳性能。多次添加C实现了原油层厚度的最大降幅（41.9%）和总石油碳氢化合物（TPH）去除率（20.6%）。然而，由于去除是由分散机制驱动的，这导致水相中的浊度增加（3.5 NTU）和毒性增加（生物荧光抑制61.6%）。相比之下，在原油层减少（38.5%）和TPH去除（17.8%）方面具有相似性能的BS导致较低水平的浊度（1.8 NTU）和毒性（生物荧光抑制26.8%）。这归因于通过分散和生物降解的去除方式。BS的生物降解与具有降解低分子和多环芳烃（即BTEX和PAHs）能力的假单胞菌属的高相对丰度有关。结果表明，BS是促进碳氢化合物去除的最具可持续性产品。在最佳S:O比（C为1:5，BS为1:10）和35°C的高温下，观察到对修复过程有显著影响。我们的研究结果阐明了通过表面活性剂/生物表面活性剂进行地下水修复的机制，并为其原位应用提供了最佳参数。
