School of Food Technology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Muang District, Nakhon Ratchasima 30000, Thailand; Department of Food Science and Chemistry, College of Science and Mathematics, University of the Philippines Mindanao, Barangay Mintal, Davao City 8022, Philippines.
School of Food Technology, Institute of Agricultural Technology, Suranaree University of Technology, 111 University Avenue, Muang District, Nakhon Ratchasima 30000, Thailand.
Water Res. 2017 Nov 1;124:308-319. doi: 10.1016/j.watres.2017.07.047. Epub 2017 Jul 21.
Fat, oil, and grease (FOG) deposit, in the form of calcium soap, was found to cause sanitary sewer overflows due to its adhesion on pipe walls. To address this problem, laboratory-prepared calcium soaps have been used to investigate the formation mechanisms of FOG deposits. However, the fats and oils previously utilized were limited and some soap characteristics were not examined. This research attempted to probe through the properties of calcium soaps prepared from calcium chloride and the fats and oils of chicken, pork, palm olein, soybean, olive, and coconut to further understand FOG formation and stability. Results revealed that FOG deposits may occur as smooth, paste-like material or coarse, semi-solid substance depending on their exposure to excess fat/oil and calcium. The smooth soaps with more excess fat/oil demonstrated high apparent viscosity and consistency index, while the coarse soaps with large levels of calcium signified higher melting endset. Moreover, a soap microstructure showing evident networks and lesser void area displayed higher heat and rheological stability, respectively. Overall, fats and oils with higher oleic to palmitic acid ratio such as palm olein oil, olive oil, chicken fat, and pork fat produced soaps with greater yield and degree of saponification. Hence, establishments and authorities should be alert in managing and monitoring these wastes. On the other hand, soybean oil high in linoleic acid and coconut oil high in lauric acid do not pose an immediate threat to the sewer system since they only produced soaps in small quantity. However, their soaps showed high melting endset which could pose a serious effect when accumulated at large amount. On the whole, the fatty acid profile of fats and oils, the presence of excess fat/oil, and calcium content mainly dictate the appearance, melting, rheology, and microstructure of calcium soaps. Their distinct properties can be used as criteria in predicting the condition and stability of FOG deposits.
脂肪、油和油脂（FOG）沉积物以钙皂的形式存在，由于其在管壁上的附着力，会导致卫生下水道溢出。为了解决这个问题，已经使用实验室制备的钙皂来研究 FOG 沉积物的形成机制。然而，以前使用的脂肪和油有限，并且没有检查一些肥皂特性。本研究试图通过氯化钙和鸡、猪、棕榈仁油、大豆、橄榄油和椰子油的脂肪和油制备的钙皂的性质来进一步了解 FOG 的形成和稳定性。结果表明，FOG 沉积物可能表现为光滑的糊状物质或粗糙的半固态物质，具体取决于它们与过量脂肪/油和钙的接触情况。具有更多过量脂肪/油的光滑肥皂表现出高表观粘度和稠度指数，而具有大量钙的粗糙肥皂则表示较高的熔点终点。此外，显示出明显网络和较少空隙面积的肥皂微观结构分别表现出更高的热稳定性和流变稳定性。总的来说，油酸与棕榈酸比例较高的脂肪和油，如棕榈仁油、橄榄油、鸡油和猪油，产生的肥皂产率和皂化程度更高。因此，管理和监测这些废物时，机构和当局应保持警惕。另一方面，亚油酸含量高的大豆油和月桂酸含量高的椰子油对下水道系统不会构成即时威胁，因为它们只产生少量的肥皂。然而，它们的肥皂表现出较高的熔点终点，当积累到大量时可能会产生严重影响。总的来说，脂肪和油的脂肪酸谱、过量脂肪/油的存在以及钙含量主要决定了钙皂的外观、熔融、流变学和微观结构。它们的独特性质可用于预测 FOG 沉积物的状况和稳定性。
