‘Green’ school promotes waste value

June 16, 2021 - 10:51

Primary school of Trần Đại Nghĩa in Đà Nẵng began a recycling kitchen system to reduce 60 per cent of waste released each month, saving VNĐ1 million ($43) in garbage treatment fees, while producing 100kg of nutritional compost each month.

by Công Thành

Trần Hoàng Vy, from the Đà Nẵng University of Technology and Education checks compost quality at a primary school in the city. VNS Photo Công Thành 

Primary school of Trần Đại Nghĩa in Đà Nẵng began a recycling kitchen system to reduce 60 per cent of waste released each month, saving VNĐ1 million (US$43) in garbage treatment fees, while producing 100kg of nutritional compost each month.

The Cẩm Lệ district-based school often disposes of six dust bins each day, but now only two bins are transported to landfill.

It’s the first school in Đà Nẵng applying waste treatment under the pilot of Waste-Free Schools model of the Building Healthy City (BHC) programme – one of East Meets West Organisation's key programmes in building a healthy and clean study environment for school students in the central city.

Having passed a one-year test run, a group of students and lecturers from the Đà Nẵng University of Technology and Education (UTE) launched the COM-UTE vessel composting version 2.0 system, or the COM-UTE-V2 system – the first ever local made organic waste treatment system in central Việt Nam – at the school for recycling daily kitchen waste into compost.

School students begin training with garbage classification at source under the project of the Việt Nam Zero Waste Alliance. Photo courtesy of Việt Nam Zero Waste Alliance

“It’s perfect. Daily 10kg leftover food, which used to be disposed of, now helps the school’s kitchen earn at least 5kg of compost each day," said the school’s principal, Trương Thị Bích Thủy.

"No smells or pollutant come out from the process.

“The system helps train students skills of garbage classification and practical waste treatment courses at school.”

Dr Phạm Phú Song Toàn, an environmental scientist, founder of the COM-UTE-V2 system and leader of the research group, said the project had succeeded in killing bad smells and reducing the waste processing time that previous solutions failed to do.

“The manual version had been tested in a one-year pilot project at the university. It has two successful advantages – quick disintegration and non-smell,” Toàn said.

“Thermal aerobic microorganism – a key brain factor of the biodecomposition system – was used to let disintegration process go faster in temperature of 60 or 70 degrees Celsius.”

Toàn, who researched environmental science at Okayama University in Japan, revealed the waste treatment system was made from recycled materials for mass low-cost manufacture.

He said the easy design and operation low-cost system could be acceptable at schools and communities in urban areas.

Waste-free school

Waste classification zone at the Trần Đại Nghĩa primary school in Đà Nẵng. School students are educated about the correct way to dispose of waste. VNS Photo Công Thành 

Trần Hoàng Vy, a final year student at the university’s chemistry technology and environment faculty, said the COM-UTE-V2 system was a comfortable model in terms of time, design and control.

“We use a cutting machine to chop waste before mixing it with saw dust and aerobic microorganism in rotary drums for decomposing," Vy said.

"The mixture needs spinning every two-days for the thermal aerobic microorganism to work well.

“Aerobic microorganism decomposes completely organic waste within 30 days – shorter than natural disintegration (from 35 to 50 days). No bad smells or leaks were released during the process.

“Two thirds of processed compost will be taken out for use, while the remaining will be reserved for new waste treatment. It means that the system will not need supplemental aerobic microorganism.”

The system will set up an initial steps for wider use at other schools in Đà Nẵng.

“The waste-free schools (WFS) model has earned positive results in processing school kitchen waste into compost for organic crops and soil improvement," said Trần Thị Thúy Hà, project manager from the East Meets West organisation.

"It will soon be transferred to other schools in the city to boost waste classification at source.” 

Hà said the model would help change the behaviour and manners among teachers and students in terms of waste sorting at source, garbage collection, plastic waste reduction and waste recycling, while building 4R model (Refuse-Reduce-Reuse-Recycle) at school environment.

A smart dust bin is set up on a pavement in Đà Nẵng. It offers waste classification and a solar power source for phone charging. Photo courtesy of Bridgeston Viet Nam

She said EMWF hoped the WFS model would spark more waste treatment at source among communities in Đà Nẵng.

Hà said EMWF and sponsors donated containers to 12 primary schools in Hòa Vang District of Đà Nẵng promoting the WFS model in the city.

Dr Toàn said 80 per cent of daily 1,100-tonne waste in Đà Nẵng could be recycled by promoting waste classification at source, and the system would be a positive sample for mass use.   

He said at least 400 tonnes of organic waste, of which 50 per cent was biodegradable, could be collected by sorting out each day for recycling.

The COM-UTE-V2 system could improve calorific value of waste in feeding dried material for better operation of waste-to-energy incinerators, he added.

A milk carton is collected at a primary school for recycling. Đà Nẵng plans to collect milk cartons in a campaign building zero waste school zones. VNS Photo Công Thành 

The research group has been seeking co-operation with Lagom Việt Nam company and TetraPak in recycling daily 10 tonnes of milk cartons from schools in Đà Nẵng.

He said COM-UTE-V2 system would be an environmental education practical example to help students become ‘green’ ambassadors of zero-waste community’s development in the city in the future.

“School students will help transmit ‘zero waste’ school message in the community by promoting the role of waste classification among families and communities,” Toàn said. VNS