Methods of natural wastewater treatment in Vietnam

3 Methods of Natural Wastewater Treatment in Vietnam

1. Constructed Wetlands

Constructed wetlands are a simple method of wastewater treatment that is widely used today. The basic principle is to use natural wetlands to clean wastewater through the physical, chemical, and biological processes of soil, water, and plants.

Advantages of Natural Wastewater Treatment with Constructed Wetlands

• Simple wastewater treatment process, no need for many subsequent treatment methods.
• Nutrients in wastewater can be reused for various purposes.
• Water can be recharged into underground water reservoirs.

Constructed wetlands require less energy to operate. They only need energy for water transport and irrigation on the soil surface. In contrast, other methods require a lot of energy for water transport, mixing, aeration, pumping, and water circulation.

Therefore, it is easy to see that using constructed wetlands helps save costs compared to other methods.

Limitations of this method

Although it is effective and cost-saving, constructed wetlands have the limitation of requiring a large land area. Additionally, they depend heavily on soil structure and climatic conditions.

Types of Constructed Wetlands

Some types of constructed wetlands for wastewater treatment include:

• Slow-flow constructed wetlands.
• Free-water surface constructed wetlands.
• Rapid flow constructed wetlands.

2. Surface Flow Wetlands

Surface flow wetlands are effective waterlogged ecosystems for wastewater treatment. The water level here is usually deep, close to the ground surface, and can grow various types of plants.

Here, plants use solar energy to absorb carbon from the atmosphere and convert it into energy for the living activities of microorganisms.

Surface flow wetlands can treat organic substances from domestic, industrial, and rainwater. They also create a beautiful landscape due to the biological diversity of the wetland.

Advantages

Effectively treat organic substances in wastewater.

• Remove viruses and pathogens in the wetland through settling, filtering, and destruction processes.
• Remove some heavy metals through accumulation in the wetland as sediment.
• Create habitats for wild animals, waterfowl, promoting biodiversity.
• Create ecological landscapes, recreational areas, providing many benefits for humans such as fishing, planting...

Limitations

Similar to constructed wetlands, surface flow wetlands require the use of extremely large land areas to achieve good wastewater treatment efficiency.

Types of Surface Flow Wetlands

Based on the flow, surface flow wetlands can be divided into 2 types:

• Surface flow wetlands.
• Subsurface flow wetlands.

3. Bioponds

Bioponds are natural or artificial structures used to stabilize wastewater flow under different climatic conditions. These structures can treat various types of wastewater such as industrial wastewater, domestic wastewater.

In bioponds, secondary waste sources are removed through the decomposition of organic matter by microorganisms. This can be a single pond structure or combined with other water treatment methods.

Advantages

• Easy to construct: After excavation, investors will proceed with subsequent tasks such as building water pipes, embankments, waterproof linings... Additionally, you can also use natural ponds to treat wastewater.
• Low cost: Because this is a simple structure. When operating, there is no need to use expensive mechanical and electrical equipment. At the same time, it does not consume electricity or require highly skilled labor. Therefore, the operating costs are relatively low.
• High buffering capacity: Bioponds can withstand wastewater with high concentrations of heavy metals. Especially, they regulate well the organic shock phenomena or unstable hydraulic loads of the incoming wastewater.
• Superior efficiency: The efficiency of this structure can treat 90% of BOD, 70 - 90% of nitrogen, and 30 - 50% of phosphorus in wastewater. In addition, this structure can effectively remove disease-causing microorganisms in wastewater without using other treatment methods such as chlorination, ozonation, or UV radiation.

Limitations

The issue of land prices, the permitted land area is a significant factor affecting the effectiveness and cost of using bioponds.

Above is the sharing of experts from Toan A JSC about natural wastewater treatment. We hope that the information we provide has helped you understand more about the methods and natural wastewater treatment facilities currently being applied. These are all methods that bring high efficiency, are environmentally friendly, and easy to apply if there are good land conditions.

For more detailed information, please contact us at the hotline 0913 543 469 for the most necessary advice and information.