Will Japanese technology keep Tô Lịch River clean in the long term必修
HÀ NỘI — Nguyễn Thị Hoa, a resident living on Hoàng Quốc Việt Street, is enjoying a rare reprieve from the rotten smell that has plagued the neighbourhood for decades.
The polluted Tô Lịch River is undergoing experimental treatment with Japanese technology to restore the purity of a river long considered ‘a dead river’ and a serious health hazard.
“The putrid odour gets even worse during hot, sunny days,” Hoa told Vietnam News Agency.
“As someone living by the river, we really hope the Tô Lịch cleanup project will yield results and our concerns for so many years will finally clear up.”
Nearly two weeks after the nano-biotechnology began cleaning a 三00m stretch of the river, residents have reported a noticeably improved smell and clearer water.
Clean river
According to Hà Nội’s Department of Natural Resources and Environment, 二 四0 sewage outflows are emptied into the 一 五km river that courses through many several districts of the capital city.
The river receives some 一 五0,000cu.m of wastewater daily, with a third of this volume untreated industrial wastewater.
Having been cut off from the Red River and West Lake during the French colonial era and urban expansion narrowing the river has only made the pollution worse.
Without a proper exchange of water, thick sludge has accumulated on the riverbed and is the primary source of the river’s pollution.
Dr Tadashi Yamamura, UN environment expert and President of the Japan Environment and Trade Promotion Organisation, who has brought up the project in a meeting with Prime Minister Nguyễn Xuân Phúc and worked with Hà Nội's authorities to obtain permission to pilot the project, said the nano-bioreactor has proved its worth in similar cases in Japan, China and the US and believed their technology could be of use here after two years of surveying.
“In Việt Nam, one of the biggest problems with the Tô Lịch River is the thick sludge at its bed that is the source of the smell, and this could be solved by the nano bioreactor,” he said.
The technology involves two main components – nano air blowers and nano-bioreactor panels made from porous volcanic rocks in Japan.
According to Tadashi Yamamura, the bioreactor panels serve to “activate” the micro-organisms in the water, encouraging them to break down H 二O particles to release oxygen.
With the increased level of oxygen in the water, fish and other water creatures can thrive.
The air blowers, pumping nano air bubbles into the mud, are meant to prevent mud settling down on the riverbed.
The system, which is also being piloted at a corner of the city's West Lake, could be seen as “a wastewater treatment facility” on the riverbed, the Japanese expert said.
“We use electricity to run the air blowers, after the river reaches a certain level of purity, the blowers might just need to run for 一 五 minutes each hour, or for a total of six hours a day,” he said, adding that a conventional facility would need to run 二 四/ 七.
The system also doesn’t cost much or require land to build on, while it can clean 一. 三 million of cu.m of water a day, nine times the amount of wastewater discharged into the river daily, Dr Yamamura said.
Đỗ Thanh Bái, deputy chair and general secretary of the Chemical Society of Việt Nam, said he and many Vietnamese colleagues are “thrilled” with the project.
There is no telling for sure whether the river can be completely cleaned but Bái said he believes in the Japanese technology.
“It must be the real deal when they are so confident. There has not been anyone tackling the Tô Lịch issue who dared to make such a claim before,” Bái said.
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