In this research, benzene, a toxic compound encountered in industrial wastewater, was extracted using a mixture of saponin and sodium dodecyl sulfate (SDS) as anionic surfactants. Also, a biosensor system for assessment of toxicity and detection of extracted benzene was designed using the Luc strains of luminescent Escherichia coli. Results showed saponin and SDS were synergistic for the extraction of benzene. An optimal hydrophilic–lipophilic balance value for extraction was determined to be about 24.1, representing a mixture of 40 wt% SDS and 60% saponin. Under optimal conditions, the concentration of extracted benzene in extraction phase reached 27 ppm. When extracted benzene solution was injected into the biosensor system, the luminescence level of biosensor decreased dramatically, reflecting toxicity. The concentration of benzene in the extracted solution correlated well with toxicity levels measured by the biosensor system. Using the luminescence biosensor system, the half-maximal effective concentration (EC₅₀) value of benzene was about 26.2 ppm. Our results demonstrate that the designed biosensor system has good sensitivity for toxicity assessment of extracted benzene, and therefore can be proposed as an approach to detect of benzene and other toxic compounds in wastewater.

中文翻译：

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用发光生物传感器对皂苷生物表面活性剂从废水中提取苯的毒性评价与检测

在这项研究中，苯是一种在工业废水中遇到的有毒化合物，使用皂苷和十二烷基硫酸钠 (SDS) 的混合物作为阴离子表面活性剂进行萃取。此外，使用发光大肠杆菌的 Luc 菌株设计了一种用于评估毒性和检测提取苯的生物传感器系统。. 结果表明皂苷和SDS对苯的提取具有协同作用。确定提取的最佳亲水-亲油平衡值约为 24.1，代表 40 wt% SDS 和 60% 皂苷的混合物。在最佳条件下，萃取相中苯的萃取浓度达到27 ppm。当提取的苯溶液注入生物传感器系统时，生物传感器的发光水平急剧下降，反映了毒性。提取溶液中苯的浓度与生物传感器系统测量的毒性水平密切相关。使用发光生物传感器系统，半最大有效浓度（EC ₅₀) 苯的值约为 26.2 ppm。我们的结果表明，所设计的生物传感器系统对提取苯的毒性评估具有良好的敏感性，因此可以作为一种检测废水中苯和其他有毒化合物的方法。