The nano-Bioreactors put on Tô Lịch River. Photo cafeF.vn

HÀ NỘI — Discharging water from the West Lake into the Tô Lịch River swept away good micro-bacteria created by nano-bioreactor panels which was put into Tô Lịch River two months ago, according to the Japan Environment and Trade Promotion Organisation.

Dr Tadashi Yamamura, president of the Japan Environment and Trade Promotion Organisation (JETRO), the group cleaning the polluted Tô Lịch, yesterday send a letter to the Prime Minister, Ministry of Natural Resources and Environment and Hà Nội’s People’s Committee to delay the termination of the trial cleaning project until September 17.

In the letter, Yamamura noted initial positive results after two months of using the Japanese nano-bioreactor.

However, on July 9, the Hà Nội Sewage and Drainage Company discharged more than 1.5 million cu.m of water from West Lake into the Tô Lịch River.

According to JETRO, if the project was carried out on all the river, the flow of water would spread good micro-bacteria created by the nano-bioreactors, but the project was carried out as a trial on 300m of the river so the micro-bacteria were swept away.

He said the organisation needed more time to re-activate the micro-bacteria system.

JETRO also asked the People’s Committee to adjust water discharge plans until the project was completed.

A representative of the Hà Nội Sewage and Drainage Company said the discharge was carried out in line with municipal regulations.

“Per the city’s regulations, when the water level of the West Lake was up to dangerous level, the company had to discharge water to ensure safety," the representative said.

“So it was normal the company did not inform JETRO about the water discharge," he said.

On May 16, Japanese experts installed the nano-bioreactor system in a polluted section of the Tô Lịch River.

A section of the river near Hoàng Quốc Việt Street in Cầu Giấy District was chosen for installation as the most polluted part of the river. VNS