At a coastal resort in Ninh Thuan, in the middle of the peak season for international visitors, the wastewater system in the main kitchen area suddenly overflowed. The wastewater was cloudy and emitted a foul odor that spread to the auxiliary area and the reception area. The cause was determined to be due to the amount of grease discharged from the food processing process not being separated and filtered, accumulating for a long time in the pipes, obstructing the flow.

This is not a rare case. According to a survey by an environmental engineering company operating in Ho Chi Minh City, about 80% of medium and large-scale restaurants and resorts do not have a standard grease separation system. "Grease is not only a difficult-to-treat waste, but also the main cause of pipe blockage, odor and disruption of the microbial ecosystem in the entire wastewater treatment system," said engineer Nguyen Hoang T., who has been in charge of many wastewater treatment projects for resorts in Khanh Hoa. Where does grease in wastewater come from?
In any professional kitchen, grease is an indispensable ingredient - from frying, stir-frying, grilling to cooking soups and making sauces. After use, grease is often washed away with dishwashing water, kitchen cleaning water or escaping from food surfaces.
However, unlike water and common organic impurities, grease does not dissolve, tends to float and stick strongly to the walls of pipes, tanks or grease traps. Over time, they form a thick layer of grease, causing blockage and impeding the flow.
A study by the Institute of Environmental Technology shows that just 1 liter of untreated waste oil can pollute up to 1 million liters of clean water. In a humid and airtight environment, grease will decompose anaerobically, producing H2S and CH4 gases - two compounds that smell like rotten eggs, are extremely unpleasant and can be toxic to humans. Grease trap - forgotten equipment
A grease trap, also known as a grease trap, is a device with a simple structure consisting of three compartments: receiving - separating grease - discharging waste. Based on the principle of layering between water and grease, this system retains excess grease before the water enters the main treatment system.
However, in many resorts, grease traps are still overlooked or not regularly maintained. "Some places install small stainless steel tanks, then forget them for months. When the tank is full, grease overflows into the pipes and causes blockages. Some places do not even install tanks because they think it is an unnecessary cost", said Mr. Tran Van Dung - a technical specialist at a wastewater treatment unit in Da Nang.
Not having a grease trap or using it incorrectly can lead to a series of consequences: from clogged pipes, spreading bad odors, to paralysis of the entire biological wastewater treatment system behind. When microorganisms are destroyed by too much grease, the wastewater cannot be cleaned, forcing it to discharge waste beyond standards - violating the law and causing serious damage to the environment.
Resorts face double risks
In recent years, many resorts in provinces such as Binh Thuan, Khanh Hoa, Phu Quoc ... have begun to face a wave of periodic environmental inspections from authorities. Many units have been fined from 50 to 200 million VND for discharging waste containing grease exceeding technical standards.
In addition to the fines, the consequences are more serious in terms of operation. A clogged kitchen system during peak season can cause the resort to lose customers, affecting the brand image. Troubleshooting is often lengthy, including grease suction, unclogging, and even dismantling the pipe system and re-construction, costing tens of millions of VND for each treatment. What is the solution to the problem of waste grease?

According to environmental experts, there are three main solutions:

Install a grease trap that meets standards and is suitable for the kitchen capacity.

Regular cleaning: on average 7-10 days/time depending on the scale.

Combine microbial preparations: use strains of bacteria that can decompose grease, helping to reduce accumulation, deodorize, and protect the biological treatment system behind.

Some high-end resorts have now applied microbial solutions imported from the US, with high efficiency in decomposing grease, not corroding pipes, and being environmentally friendly. "Using microorganisms is a long-term solution, especially suitable for the green resort model," said engineer Nguyen Hoang T.