Abstract One of the main challenges in the surfactant flooding process, used as a chemical based enhanced oil recovery (EOR) method, is the surfactant adsorption phenomenon. This paper highlights the adsorption equilibrium of Morus nigra leaf extract in aqueous solutions as a newly introduced cationic biosurfactant on carbonate minerals. A conductivity technique utilized to assess the adsorption of the surfactant in the aqueous phase. The adsorption data examined using four different equilibrium adsorption isotherm models (Langmuir, Freundlich, Temkin, and linear). The results confirm that the Langmuir isotherm model has the best match to experimental data with a coefficient of determination of 0.9960. Moreover, a comparison between the adsorption density of Morus nigra and Ziziphus Spina Christi (a nonionic biosurfactant) on two similar carbonate samples performed based on their adsorption mechanisms and pH values. The results of this paper can be useful in surfactant selection in EOR processes, especially for chemical flooding schemes.

中文翻译：

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一种新型阳离子生物表面活性剂在碳酸盐矿物上的静态吸附：在 EOR 中的应用

摘要 作为一种基于化学的提高采收率 (EOR) 方法的表面活性剂驱过程中的主要挑战之一是表面活性剂吸附现象。本文重点介绍了桑树叶提取物在水溶液中作为一种新引入的阳离子生物表面活性剂对碳酸盐矿物的吸附平衡。一种用于评估表面活性剂在水相中的吸附的电导技术。使用四种不同的平衡吸附等温线模型（Langmuir、Freundlich、Temkin 和线性）检查吸附数据。结果证实，Langmuir 等温线模型与实验数据最匹配，确定系数为 0.9960。而且，根据吸附机制和 pH 值，比较了两个类似的碳酸盐样品对桑树和 Ziziphus Spina Christi（一种非离子生物表面活性剂）的吸附密度。本文的结果可用于 EOR 工艺中的表面活性剂选择，尤其是化学驱方案。