Logo of Phnom Penh Post newspaper Phnom Penh Post - From toilet to the sink: water recycling beats scary scarcity



From toilet to the sink: water recycling beats scary scarcity

Content image - Phnom Penh Post
A project in southern France recycles wastewater to irrigate fields. AFP

From toilet to the sink: water recycling beats scary scarcity

Would you take a swig of water from your faucet if it originally came from the sewer?

Treating wastewater to put it back into public use can help against water crises around the world, according to the UN, though the practice has to overcome the “yuck” factor among the public.

Wastewater that has been through a treatment plant is typically discharged into rivers.

But there is a push to tap recycled water – also known as water “reuse” – in order to ease pressure on sources of freshwater threatened by growing populations, pollution and climate change.

“Water reuse for sure will just increase and increase worldwide, because there’s no other option,” said Richard Connor, editor-in-chief of the UN World Water Development Report published by UNESCO.

Namibia’s capital, Windhoek, has been a pioneer, transforming wastewater into potable water since the 1960s, while Singapore has also developed a much-vaunted recycling system.

A potable water project is in the works in western France.

Turning recycled water – also known as reclaimed water – into something you can drink is not the main purpose of the technology.

In Mediterranean countries as well as Texas and Mexico, reclaimed water is used for irrigation in agriculture, which consumes two-thirds of freshwater abstractions around the world.

Reclaimed water can also be used for industries, to clean streets or cool power stations.

‘Untapped resource’

There are two ways to turn wastewater into potable water.

It can be treated and then blended with freshwater in a surface reservoir or groundwater aquifer before undergoing additional treatment and being distributed.

But the other, rarer method does not use such environmental buffers, as wastewater is purified and then sent directly to a drinking water distribution system.

Content image - Phnom Penh Post
Treating wastewater to put it back into public use for irrigation, industrial uses and even drinking could help alleviate the water crises. AFP

“Water ‘reuse’ is definitely part of the solution. It’s a way to increase our supply,” Connor said.

“If you can reuse the water several times, then you don’t have to extract it from the source,” Connor said.

Astronaut drink

Recycling wastewater is less expensive and uses up less energy than desalinating sea water, which is considered another solution against water scarcity.

“It’s better to jump on the train now,” Connor said.

“The longer you wait, the more expensive it’s going to be, and the more difficult it’s going to be. It’s better to start right away.”

The western French department of Vendee is joining the fray, announcing plans last month to turn wastewater into potable water by 2024.

The water will go though several stages of filtration and disinfection before being discharged into a reservoir.

“Everyone now understands that we must be frugal with groundwater,” said Nicolas Garnier of Amorce, an association of cities.

In the past two years, 90 per cent of communities in France have had to restrict water use due to droughts, Garnier said.

Europe represents a small percentage of the global recycled water market, according to Water Reuse Europe, a non-profit association.

It is five times more expensive to treat wastewater than water from a river or a lake because it is much dirtier, Connor said.

More than 80 per cent of the world’s wastewater is dumped in the environment without treatment, especially in poor countries, according to a 2017 UN report that called wastewater the “untapped resource”.

“We have to find ways, especially in developing countries that don’t have the funds, to pay to treat water,” he said.

One way to reduce costs would be to take sludge from the treated water to obtain biogas or extract nutrients such as nitrogen and phosphorus which can be converted into fertiliser.

But the “yuck factor is not just for drinking water”, Connor said, even though the food people consumer has been safely grown thanks to reused water.

Connor points out that astronauts on the International Space Station drink water that was recovered from the crew’s sweat and urine.

“No astronaut has ever gotten sick from the reuse of water,” he said.

MOST VIEWED

  • Prince Norodom Ranariddh passes away at 77

    Prince Norodom Ranariddh, the second son of the late King Father Norodom Sihanouk and former First Prime Minister of Cambodia, has passed away in France at the age of 77. “Samdech Krom Preah Norodom Ranariddh has passed away this morning in France just after 9am Paris-time,”

  • General’s gun smuggling ring busted

    The Military Police sent six military officers to court on November 22 to face prosecution for possession of 105 illegal rifles and arms smuggling, while investigators say they are still hunting down additional accomplices. Sao Sokha, deputy commander of the Royal Cambodian Armed Forces and commander of

  • Cambodia, Thailand to discuss border reopening

    Cambodian authorities from provinces along the Cambodia-Thailand border will meet with Thai counterparts to discuss reopening border checkpoints to facilitate travel, transfer of products and cross-border trade between the two countries. Banteay Meanchey provincial deputy governor Ly Sary said on November 22 that the provincial administration

  • More Cambodians studying in US

    The number of Cambodian students studying at US colleges and universities in 2020-21 increased by 14.3 per cent over the previous year despite the Covid-19 pandemic, according to a recent US government report. The 2021 Open Doors report on International Educational Exchange showed that 848 Cambodian students studied

  • Banteay Meanchey gunfight sees 15 Thais arrested, three officers injured

    The Banteay Meanchey Military Police have arrested 15 Thai suspects and their accomplices after a gun battle between two Thai groups caused injuries to three police officers in the early hours of November 21, local authorities said. National Military Police spokesman Eng Hy said that according to

  • PM: Do not defile Tonle Sap swamp forest or else

    Prime Minister Hun Sen ordered police to arrest anyone – including government officials – involved with the deforestation of the flooded forests surrounding the Tonle Sap Lake because it is an area important to the spawning of many species of fish, among other reasons. Speaking in a