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What is hotel wastewater treatment?

Hotel wastewater treatment is the process of removing pollutants in wastewater generated from hotel operations before being discharged into the environment. The aim is to minimize negative impacts on human health and the ecosystem.

Thus, hotel wastewater treatment is an indispensable step to ensure tourism development in harmony with the environment. Hotel wastewater includes the following main types:

• Domestic wastewater: from toilets, bathrooms, kitchens, laundry.
• Wastewater from swimming pools and spas: contains disinfectant chemicals and impurities.
• Garden wastewater: fertilizer and pesticide residues.
• Restaurant and bar wastewater: grease, leftover food, cleaning chemicals.
• Rainwater runoff: carries away dirt from roofs, yards, and roads.

The composition of hotel wastewater is quite diverse, including organic matter, suspended solids, oil and grease, nutrients (N, P), microorganisms, chemicals… Depending on the size and type of guests hotels where the composition ratio and wastewater flow will be different.

The amount of hotel wastewater every day is extremely large

Reasons to treat hotel wastewater?

Hotel wastewater treatment is an urgent issue for the following reasons:

• Environmental protection: Wastewater contains many pollutants that are harmful to receiving water bodies such as rivers, lakes, and seas. Wastewater treatment contributes to preventing environmental degradation and preserving biodiversity.
• Protecting public health: Wastewater contains pathogens, toxic chemicals, and heavy metals that cause adverse health effects if exposed to humans. Wastewater treatment helps prevent diseases and ensures safe water sources.
• Minimize odors: Decomposed wastewater causes unpleasant odors and is unsightly. Wastewater treatment helps improve the landscape, creating a clean environment to attract tourists.
• Enhance reputation and brand: Hotels that treat wastewater well demonstrate environmental responsibility, are highly appreciated, and are friendly. This helps enhance the hotel’s image and competitiveness.
• Wastewater reuse: Wastewater after treatment that meets standards can be reused for watering plants, washing roads, and cooling. This helps save clean water and costs.

It can be seen that wastewater treatment is not only an environmental responsibility but also brings many practical benefits to the hotels themselves.

Regulations on hotel wastewater treatment

Currently, Vietnam has issued many legal regulations requiring tourist accommodation establishments to treat wastewater to meet standards before discharging into the environment:

• The 2017 Law on Tourism stipulates that tourist accommodation establishments must have measures to protect the environment and treat wastewater.
• The 2020 Environmental Protection Law prohibits the discharge of wastewater that has not been treated to meet standards into the environment.
• Circular 06/2022/TT-BTNMT stipulates that hotel wastewater must be treated to meet National Technical Regulations on domestic wastewater QCVN 14:2008/BTNMT before being discharged into receiving sources.
• Decree 155/ND-CP regulates penalties for administrative violations in the field of environmental protection. Accordingly, the act of discharging wastewater that does not meet standards will result in a fine of 150-300 million VND.

Therefore, hotels need to strictly comply with regulations on wastewater treatment to avoid fines and contribute to environmental protection.

Regulations on hotel wastewater treatment

Stages of hotel wastewater treatment

Hotel wastewater treatment usually includes 4 main stages:

1. Preliminary treatment

The purpose of this stage is to remove large suspended solids before entering the treatment system. The main stages include:

• Screening (separating) waste: using screens and filters to retain trash, plastic bags, and obstacles.
• Grease separator: removes grease from the kitchen area that floats to the surface of the wastewater.
• Collection tanks and septic tanks: sedimentation and preliminary decomposition of wastewater before entering the treatment system.

2. Biological treatment

The nucleus of the wastewater treatment process is this stage. It uses microorganisms to decompose organic pollutants under aerobic (with oxygen) or anaerobic (without oxygen) conditions. Main steps:

• Anoxic tank: denitrification in an oxygen-deficient environment thanks to bacteria.
• Aerotank (aerobic tank): provides oxygen for aerobic microorganisms to decompose organic matter.
• Biological sedimentation tank: sedimentation of microbial sludge to retain microorganisms for the aerotank.

This step helps significantly reduce the concentration of organic pollutants and nutrients, improving water quality.

3. Chemical treatment

To improve treatment efficiency, some hotels can apply chemical treatments such as:

• Flocculation and flocculation: add alum or PAC to wastewater to create floc to absorb colloidal pollutants.
• Disinfection: use chlorine and UV rays to disinfect post-treated wastewater.

This is the most important stage in the hotel wastewater treatment process. The chemicals used come from Dong A Chemical, ensuring the highest quality and reputation today.

4. Sludge treatment

During the wastewater treatment process, sludge is generated from sedimentation tanks and biological tanks. They contain many organic substances and microorganisms that need to be thoroughly treated:

• Thicken (compress) sludge to reduce sludge volume.
• Sludge stabilization through anaerobic, aerobic or chemical digestion.
• Dewatering sludge using sludge dewatering machine and heat drying system.
• Use sludge as compost or sanitary landfill.

Proper sludge treatment helps avoid odors, flies and the risk of soil pollution.

Stages of hotel wastewater treatment

Hotel wastewater treatment technologies

There are many hotel wastewater treatment technologies being applied in Vietnam:

No technology is perfect and suitable for all types of hotels. The choice of treatment technology depends on the wastewater source, size, location, budget and environmental goals of each hotel.

Hotel wastewater treatment process

A standard wastewater treatment system for hotels may include the following main works:

1. Sand sedimentation tank and grease separator

This tank has a preliminary role in removing sand residue (avoiding sedimentation) and grease (reducing load on the biological system) before entering the main tank. Wastewater will be stored in this tank for a certain period of time to settle the sand below, then remove the excess sand and then supply water to the equalization tank.

2. Air conditioning tank

The regulating tank has the function of adjusting the flow and concentration of input wastewater to stabilize it, avoid load shock and ensure the system operates effectively. Water after being sanded will be transferred to the equalization tank.

3. Anoxic tank

Anoxic tank is a biological treatment tank in low oxygen (anoxic) conditions. Microorganisms in the tank use Nitrogen instead of Oxygen to decompose organic matter. This process helps significantly reduce nitrogen content in wastewater.

4. Aerotank

Aerotank (or aerobic tank) is where the decomposition of organic matter occurs thanks to aerobic microorganisms (microorganisms need oxygen). Oxygen is continuously supplied into the tank thanks to the aeration system to maintain the activity and growth of microorganisms.

5. Biological sedimentation tank

The water – sludge mixture from the Aerotank tank will flow into the biological sedimentation tank. Here, the microbial sludge (containing microbial biomass) is settled to the bottom of the tank and separated from the water. Part of the sludge will be circulated to the Aerotank to maintain the microbial concentration. The excess sludge will be periodically pumped to the sludge treatment tank.

6. Disinfection tank

The water behind the biological sedimentation tank has met discharge standards. However, to ensure safety, water can be disinfected with chlorine or UV rays before discharging into the public sewer system.

Above is a typical hotel wastewater treatment process with AAO (Anaerobic, Anoxic, Oxic) technology. Depending on the size and characteristics of each hotel, the chain can change and add other auxiliary works.

Hotel wastewater treatment process

The most popular hotel wastewater treatment chemicals today

Chemicals play an important role in the hotel wastewater treatment process, providing quick results and extremely reasonable costs. Some commonly used chemicals include:

• PAC chemical: This is a substance that has a quick flocculation time, is easily soluble in water and has extremely strong hygroscopic properties. PAC contains a lot of aluminum cations, so it creates little sludge.
• Soda Flakes NaOH: Caustic soda is produced in white solid or liquid form, plays the role of cleaning water, increasing pH, and is commonly used in hotel wastewater treatment.
• Chlorine: This is a chemical used to kill bacteria, disinfect, clean equipment and wastewater. Not only that, chlorine is also used to treat domestic water supply, and is safe if used in the correct dosage.

Currently, chemicals for hotel wastewater treatment are produced in large quantities by Dong A and distributed nationwide, meeting all water treatment needs of businesses and hotels. If you need a quote, please call HOTLINE 0822 525 525 immediately.

PAC Dong A wastewater treatment chemicals

Who is responsible for hotel wastewater treatment?

The hotel is the main unit responsible for treating its wastewater before discharging it into the environment or the urban drainage system. In case the hotel does not have a treatment system or the treatment does not meet standards, a unit with wastewater treatment functions must be hired to collect and treat it safely. The state environmental management agency is responsible for inspecting and monitoring hotel waste discharge and handling violations, if any.

To reduce wastewater at the source, hotels can:

• Use water-saving sanitary equipment such as showerheads and dual-flush toilets.
• Encourage guests to reuse towels and blankets if they are still clean.
• Applying water-saving laundry technology and circulating laundry water.
• Control water pipe leaks, periodically maintain and replace.
• Equipped with an automatic watering system, using rainwater instead of tap water.
• Remind employees and guests to save water through posters and documents.

Reducing the amount of wastewater not only protects the environment but also helps hotels save on water and wastewater treatment costs.

To aim for sustainable tourism development, each hotel needs to be aware of environmental protection right from the smallest things such as saving water and reducing waste. In particular, investing in an effective hotel wastewater treatment system that meets standards is indispensable. In addition to complying with legal regulations, good wastewater treatment also helps enhance the hotel’s brand and attract environmentally conscious tourists.

Nguyễn Lân Dũng

Giáo sưNguyễn Lân Dũnglà nhà khoa học hàng đầu Việt Nam trong lĩnh vực vi sinh vật học (wiki), với hơn nửa thế kỷ cống hiến cho giáo dục và nghiên cứu. Ông là con trai Nhà giáo Nhân dân Nguyễn Lân, thuộc gia đình nổi tiếng hiếu học. Giáo sư giữ nhiều vai trò quan trọng như Chủ tịch Hội các ngành Sinh học Việt Nam, Đại biểu Quốc hội và đã được phong tặng danh hiệu Nhà giáo Nhân dân năm 2010.