Introduction: operating process of domestic wastewater treatment system, 5 most modern domestic wastewater treatment technologies today

In the context of increasing urbanization, domestic wastewater treatment becomes an urgent issue to protect the environment and human health. Domestic wastewater treatment system effective not only helps to remove pollutants but also contributes to the reuse of water resources, minimizing the impact on the ecosystem. This article by Green In will introduce in detail the operating process of the domestic wastewater treatment system. At the same time, the article also updates the 5 most advanced treatment technologies today, helping you choose the right solution for your actual needs.

1. What is a domestic wastewater treatment system?

Domestic wastewater treatment system is a set of processes to remove impurities and waste from water discharged by humans in daily life. The main goal is to clean wastewater, protect the environment and increase the ability to reuse water resources, helping to reduce the loss of fresh water.
Wastewater treatment helps remove pollutants from wastewater from various sources such as households, industrial zones or medical facilities. As a result, the treated water can be discharged into the environment without causing harm or reused for other purposes.

2. Harmful effects of untreated domestic wastewater

Large amounts of untreated wastewater are discharged directly into rivers, lakes, and canals every day, causing serious pollution. This negatively affects the living environment, human health, and the economy.

• Harmful to health: Wastewater has an unpleasant odor, spreads bacteria and pathogens, and poses a risk of causing skin and respiratory diseases.
• Loss of urban aesthetics: Polluted water is often black, with lots of garbage floating on the surface, creating a messy landscape.
• Impact on environmental sanitation: Polluted water areas are breeding grounds for flies, mosquitoes and insects, increasing the risk of spreading disease.
• Reduced quality of life: Polluted areas often do not attract investment, causing local infrastructure and economy to suffer.
• Impact on agricultural production: In rural areas, polluted water reduces crop yields and affects livestock when water is used for irrigation and cleaning barns.

3. Should household wastewater be treated?

From the above harmful effects, it can be seen that wastewater treatment is an urgent issue. Wastewater treatment systems not only help protect the environment but also improve people's quality of life. The implementation of this system in residential areas, apartments, hospitals and schools is also an evaluation criterion of the Ministry of Natural Resources and Environment.

4. Operation process of domestic wastewater treatment system

An effective wastewater treatment system needs to follow a multi-step process to ensure maximum removal of harmful impurities.
Step 1: Screening
Influent wastewater passes through a screening unit to remove large debris such as rags, wood, plastic, and grease. The collected waste will be treated separately.
Step 2: Separate sand and gravel
Small solid particles such as sand and gravel are separated from the water to avoid damaging the equipment in the following steps.
Step 3: Primary treatment
In this step, the wastewater is fed into a settling tank to remove sludge and grease. These substances are then treated separately.
Step 4: Aeration
Microorganisms are used to decompose organic matter in water. This process helps convert pollutants into gas, water and biological sludge.
Step 5: Secondary treatment
Water is then fed into a settling tank to separate the activated sludge from the clean water. The sludge is reused or treated separately.
Step 6: Filter
Water passes through a filtration system to remove any remaining small particles.
Step 7: Disinfect
Ultraviolet disinfection technology is used to kill remaining bacteria, ensuring the water is safe to discharge into the environment.
Step 8: Stabilize water quality
Treated water can be aerated to adjust dissolved oxygen levels before discharge to the environment or reuse.

5. Introducing the 5 most modern domestic wastewater treatment technologies today

5.1. AO (Anoxic – Oxic) technology

AO technology is the latest domestic wastewater treatment technology, applied to treat major nutrients such as nitrogen and phosphorus in wastewater. AO technology has two main tanks: aerobic and anoxic tanks, respectively accompanied by nitrification in the aerobic tank and denitrification in the anoxic tank.
Advantage:

• Effective treatment of nitrogen and phosphorus compounds.
• Stable operation, easy to operate.
• Save operating costs by not using many chemicals.

Disadvantages:

• Oxygen concentration must be well controlled for optimal treatment efficiency.
• Cannot completely remove suspended solids, need to combine with other steps.

5.2. AAO technology (Anaerobic – Anoxic – Oxic)

AAO wastewater treatment technology is a continuous biological treatment process using anaerobic, aerobic and anaerobic microorganisms to decompose pollutants in wastewater.
Advantage:

• Simultaneously removes organic matter, nitrogen and phosphorus.
• Reduce sludge waste, helping to save treatment costs.
• Natural process, less chemicals used.

Disadvantages:

• Requires large floor space due to multiple treatment tanks.
• Close control of environmental conditions is required to achieve high performance.

5.3. SBR technology

SBR (Sequencing batch reactor) technology is a domestic wastewater treatment technology with batch biological reactions, including 2 tank clusters: Selector and C-tech.
Advantage:

• No need for multiple treatment tanks, saving space.
• Flexible control of wastewater treatment process for each batch.
• Highly effective in removing organics, nitrogen and phosphorus.

Disadvantages:

• Automatic control system is required to ensure accurate operating time.
• More suitable for medium wastewater flow, not suitable for too large scale.

5.4. MBR technology

MBR (Membrane Bioreator) wastewater treatment technology is one of the popular domestic wastewater treatment technologies with the combination of suspended microorganisms in the activated sludge tank with hollow fiber membrane technology, the amount of sediment in the biological tank will be retained thanks to the microfiltration mechanism of the membrane with small diameter, so the quality of wastewater after leaving the membrane is guaranteed to be of good quality.
Advantage:

• The output water quality is very high and can be reused.
• Space saving due to no need for secondary settling tank.
• Significant reduction in sludge volume.

Disadvantages:

• High initial investment cost.
• Regular maintenance and cleaning of the filter membrane is required to avoid clogging.

5.5. MBBR technology

MBBR (Moving Beb Biofilm Reactor) is a wastewater treatment technology that uses materials as a carrier for microorganisms to adhere to for growth and development. The effective biological treatment process MBBR is through the combination of activated carbon sludge and biofilm.
Advantage:

• Higher treatment efficiency than conventional activated sludge.
• Simple operation system, low sludge waste.
• Suitable for various types of wastewater.

Disadvantages:

• It is necessary to monitor the amount of substrate to ensure treatment efficiency.
• Depending on the quality of the biomedia, it can become clogged if not properly maintained.

6. Conclusion

Choice Domestic wastewater treatment system appropriate plays an important role in protecting the environment and public health. Each treatment technology has its own advantages, meeting different treatment needs. Depending on the scale, nature of wastewater and reuse requirements, businesses or households can consider the most optimal solution. Follow now Green In for more useful information!