Greywater Recycling: A Far-Fetched Dream

Greywater Recycling: A Far-Fetched DreamGreywater Recycling: A Far-Fetched Dream

Separation of drinking water and greywater is a common practiced for conserving clean water and reducing treatment costs around the world.

Greywater is any domestic wastewater produced, excluding sewage. The main difference between greywater and sewage (or blackwater) is organic loading. Sewage has a much larger organic loading compared to greywater, which is recycled and reused for non-drinking purposes.

Speaking to ILNA, Mukhtar Hashemi, an associate researcher at the Newcastle Institute for Research Sustainability at Newcastle University, England, says Iran’s biggest challenge in terms of increasing the efficiency of wastewater treatment is developing infrastructure and securing budget to separate greywater and drinking water.

He said, “In the developed world, clean water is used for drinking purposes, while greywater is used for sanitary purposes.

“For instance, the kitchen water is drinking water, while the water used in bathroom is greywater.”

Hashemi, who is a visiting lecturer at the University of Kurdestan, says separating potable water and greywater is an intricate process that requires complex infrastructure, “but because separating the two types of water was never part of Iran’s long-term plans, implementing it now will be problematic.”

The expert believes expecting huge investment in the sector is improbable because water and wastewater management companies in Iran have not yet figured out how to start turning a profit.

“Putting aside finances, Iran does not have the technology for this. Special treatment facilities need to be set up all over the country—in villages and towns—but we don’t even have enough facilities in metropolises,” Hashemi noted.

Using greywater for non-drinking purposes can reduce drinking water use by 16% to 40%, depending on the house or site. Saving on freshwater use can significantly reduce household water bills, but also has a broader community benefit in reducing demands on public water supply.