Log in
Hanoi

Japan's bio-nanotechnology cleans water in Hanoi’s polluted river

After seven days, sludge in the river’s floor began to decompose, reducing from more than one meter to about 76-91 cm, a clear layer of water appeared on the mud surface.

After seven days of treating water in Hanoi’s To Lich River with Japan’s nano-bioreactor technology, the river’s water quality has significantly improved, local media reported.

On May 31, half a month after Hanoi piloted nano-bioreactor technology in some sections of To Lich river, the river’s water gradually changed from black to milk-white and the bad smell of the river was partly disappearing.


Nguyen Van Thang, 60, who lives near the treated section, said: "In the past, my family often had to close the door the whole day because we could not bear the stench. Since the city installed Japan’s machines, bad smell of the river has reduced, we can even walk along the river bank in the afternoons".
 
The section of To Lich River is treated with Japan’s technology on May 31. Photo: Tat Dinh
The section of To Lich River is treated with Japan’s technology on May 31. Photo: Tat Dinh
Nguyen Tuan Anh, chairman of Nhat Viet Environmental Improvement Joint Stock Company, said that he received the results of To Lich river’s water quality twice, one after three days and the other after seven days piloting the nano-bioreactor technology in the river.

He cited that after three days, the stench of ammonia (NH3) decreased rapidly. After seven days, sludge in the river’s floor began to decompose, reducing from more than one meter of thickness to about 76-91 cm, a clear layer of water appeared above the mud.

"In the intermediate phase, the results help experts learn about changes of the water indicators, so we will not reveal more details. Scientifically, water indicators could only be obtained with accuracy after one or two months (of applying the technology). After two months, the amount of mud will be reduced, the river’s water will be cleaner. At that time, fish may swim on this section of the river," Tuan Anh said.

Japan's nano - bioreactor technology includes nanotechnology aeration using natural substances which the Japanese side has surveyed for two years before piloting it. The nano aeration system uses a specially-designed filter technology to extract air directly from the environment and then diffuse it into the water in the form of nano-sized air bubbles, according to Tuan Anh.

He added that the diffusion of nano-sized air bubbles in the water increases the dissolved oxygen content in the treated water area, including groundwater. As a result, aerobic microorganisms will be activated and natural metabolic processes will be nourished, the final nutrition chain will be improved. Recovering the nutrient chain will improve the water quality in a short time.

The quality water in To Lich river after treatment is measured independently by three units which are the General Department of Environment, the Institute of Environmental Technology under the Vietnam Academy of Science and Technology, and the Center for Quality and Protection of Water Resources. The results for the first phase of treatment are expected to be made public in late June.
Reactions:
Share:
Trending
Most Viewed
Hanoi launches digital job portal to boost labor matching

Hanoi launches digital job portal to boost labor matching

Hanoi has introduced a new digital platform designed to connect workers and employers more efficiently as the capital modernizes its labor market.

Hanoi’s 100-year master plan to shape the capital’s future growth

Hanoi’s 100-year master plan to shape the capital’s future growth

The planning must be of the highest quality so Hanoi can fully realize its distinctive potential, key opportunities and competitive advantages.

Hanoi opens 11th annual sports games celebrating unity, excellence, athletic spirit citywide

Hanoi opens 11th annual sports games celebrating unity, excellence, athletic spirit citywide

Hanoi opened the Capital Sports Games 2025 with a grand ceremony, highlighting the city’s growing sports movement, strong community participation and ambition to elevate both mass fitness and elite athletics.

Institutional breakthroughs as catalyst for Hanoi’s next leap

Institutional breakthroughs as catalyst for Hanoi’s next leap

The resolution not only empowers the city and speeds up processes but also outlines a more proactive and efficient model of urban governance for Hanoi’s future.

Hanoi commits US$230 million to curb urban flooding

Hanoi commits US$230 million to curb urban flooding

Emergency construction orders are essential to address urgent needs, including water pollution control, a stable, clean water supply, increased flows for the To Lich River and improved urban landscapes and living conditions.

Hanoi gears up for a vibrant 2026 Countdown

Hanoi gears up for a vibrant 2026 Countdown

With the energy of thousands gathering in Hanoi downtown, the Countdown 2026 promises to be an unforgettable way for people to welcome the New Year.

Hanoi launches AI-powered traffic control center for traffic violations

Hanoi launches AI-powered traffic control center for traffic violations

The system automatically detects common violations, significantly reducing the need for traffic police to be deployed directly on the streets while improving accuracy and transparency in traffic management.

Hanoi plans 10,000-hectare urban megacity with world-class stadium

Hanoi plans 10,000-hectare urban megacity with world-class stadium

The stadium’s design draws inspiration from Dong Son bronze drums and the Lac bird motif, symbolizing Vietnam’s aspiration to rise.