Train tech purifies rural wastewater
A CHINESE high-speed train maker has used its toilet technology to treat rural sewage.
In a demonstration project in Sanxing Township on the island of Chongming in Shanghai, a bioactive filter-integrated purification tank developed by CRRC Corporation Ltd, China’s largest high-speed rail carriage maker, has been installed underground about 10m away from two rural houses.
Domestic sewage from the two families is gathered by gravity flow and treated with a microbial anaerobic-aerobic process, then goes through a deep treatment with a bioactive filter in the tank.
After treatment, the sewage has been turned into clear and odourless water, which has been tested as meeting Shanghai’s first-class standard of discharged water, suitable for irrigation and supplementing natural water.
The CRRC-developed purification tank wirelessly provides realtime data on its operating conditions and decontamination results to a village control room, which means any technical issues or faults can be identified and remotely fixed in a timely fashion.
“The secret of the purification tank is the bioactive microflora that eat the dirty stuff in sewage,” said Ni Xiaohong, 25, a sewage treatment worker in Chongming.
Yang Zhen, vice-general manager of Shandong Zhongche Locomotive Co, Ltd Shanghai Branch, said the biological purification tank is based on the vacuum-drainage and biotechnology-integrated treatment devices used in toilets on high-speed trains.
Pilot projects of similar decentralised rural domestic sewage treatment equipment had been launched in over 20 provinces and regions across China since 2015, he said.
THE SECRET OF THE PURIFICATION IS THE BIOACTIVE MICROFLORA THAT EAT THE DIRTY STUFF
A small purification tank can be installed in one day. It can deal with at least one ton of sewage a day, enough for treating daily discharge from two to three families. The treated water can be sluiced directly into streams.
Yang said the tanks addressed the needs of household sewage treatment for people living in remote areas.
The Chongming district government has set the target to achieve full coverage of rural domestic sewage treatment at 2020. In some villages, drones are used to monitor water pollution.
It plans to introduce the CRRC-developed sewage tanks for isolated households.
For densely-populated villages, centralised treatment such as Shanghai Electric’s container-sized sewage treatment station using micro-dynamic, high-efficiency biofilm technology can meet the needs of sewage purification for up to 200 households.
Apart from a regular sewage treatment fee, rural residents do not have to pay for the installation and maintenance of the equipment.
The technology could help Chongming to achieve its goal of developing a world-class ecological island, said district official Xu Xiaodong. – Xinhua