Oil-in-water emulsions created in shipboard bilgewater can be challenging to treat to hydrocarbon-limiting environmental discharge regulations. While emulsion behavior has been widely studied in other disciplines, research on bilgewater emulsions has been limited due to the variability of bilgewater composition. In this context, surfactant types and concentrations are generally unknown. Therefore, experimental properties of neat surfactants and commercial cleaners were evaluated for predicting bilgewater emulsion stability. Critical micelle concentration (CMC), CMC in the presence of oil (CMC_IFT), and equilibrium interfacial tension (IFT) were investigated for emulsion stability using different surfactant types, oil concentrations, and homogenization energies. It was found that CMC was significantly larger in the presence of mineral oil. ${\Gamma }_{\infty }$ values of all three surfactants were similar for the oil-water and air-water cases; however, the $\kappa$ values were larger for the oil-water interface suggesting that, for a given surfactant, the adsorption of the surfactant molecules to the oil-water interface was more active than to the air-water interface. It was also determined that emulsion stability was most closely related to CMC_IFT. Coalescence into a separated oil layer was only observed in emulsion samples with surfactant concentrations below CMC_IFT. This relationship was observed for different homogenization intensities and oil concentrations. Experiments also validated the relationship between CMC_IFT and oil separation in more complex formulations of commercial cleaners commonly found aboard ships. Four different cleaners with unique compositions all demonstrated separated oil at concentrations below CMC_IFT. Overall, CMC_IFT represents a practical way to evaluate a cleaner's likelihood of developing stable (> 72 h with no observable oil separation) emulsions in bilgewater.

对于限制碳氢化合物的环境排放法规而言，在船用舱底污水中产生的水包油乳液可能具有挑战性。尽管在其他学科中已经对乳液行为进行了广泛的研究，但由于舱底水成分的可变性，对舱底水乳液的研究受到了限制。在这种情况下，表面活性剂的类型和浓度通常是未知的。因此，评估了纯净表面活性剂和商用清洁剂的实验性能，以预测舱底水乳液的稳定性。临界胶束浓度（CMC），油存在下的CMC（CMC _IFT），并使用不同的表面活性剂类型，油浓度和均质化能量研究了平衡界面张力（IFT）的乳液稳定性。发现在矿物油存在下CMC明显更大。${\Gamma }_{\infty }$在油水和空气水情况下，所有三种表面活性剂的值均相似。然而$\kappa$油-水界面的值较大，表明对于给定的表面活性剂，表面活性剂分子在油-水界面上的吸附活性比在空气-水界面上的活性高。还确定乳液稳定性与CMC _IFT最密切相关。仅在表面活性剂浓度低于CMC _IFT的乳液样品中观察到聚结成分离的油层。对于不同的均质化强度和油浓度观察到这种关系。实验还验证了CMC _IFT之间的关系通常在船上发现的更复杂配方的商业清洁剂中的油和油分离。四种具有独特成分的不同清洁剂均显示出分离出的油的浓度低于CMC _IFT。总体而言，CMC _IFT代表了一种实用的方法，用于评估清洁工在舱底水中形成稳定的乳液（> 72小时，没有可观察到的油分离）的乳液。