The recovery and reuse of greywater are one of the sustainable solutions to reduce water consumption in industries.
Interior Minister Ahmad Vahidi made the statement on Friday during his visit to a project site to transfer treated wastewater from Bojnourd County in North Khorasan Province to Khorasan Petrochemical Company, the Energy Ministry’s news portal reported.
The reuse of greywater is being increasingly practiced in many countries, namely the United States, Australia, Cyprus, the UK, Germany and Jordan, he added.
According to Vahidi, talks are being held with the Energy Ministry to supply industries in the region with treated greywater and contracts will be signed in the near future.
As the studies for the project are complete, the transmission line will be established in the next six months.
The petrochemical company consumes about 5.5 million cubic meters of water annually.
As the company needs more water for its development plans, and taking into account the limited groundwater resources in the province, the use of treated wastewater can meet its needs.
Greywater or sullage is treated wastewater generated in households or office buildings from streams without fecal contamination.
The main difference between greywater and sewage (blackwater) is the organic loading. Sewage has a much larger organic loading compared to greywater. Greywater is captured from household sources like sinks, hand-basins and showers.
Urban Sewage
Greywater accounts for 50% of urban sewage in the province, a large proportion of which can be recycled.
Economic experts and environmentalists argue strongly against using high quality and costly potable water for purposes that do not require quality water, like farming.
With proper treatment, greywater can be put to good use.
The uses range from toilet flushing to irrigation of plants.
Treated greywater can be used to irrigate both food and non-food production units. Nutrients in greywater (phosphorus and nitrogen) are an excellent food source for plants.
According to the interior minister, greywater accounts for 65% of urban sewage, a large proportion of which can be recycled.
By reusing greywater, demand for expensive-to-treat potable water declines, he added.
It costs the government 75,000 rials (25 cents) to produce one cubic meter of water, whereas consumers pay 40% of the total cost, which partly explains why people take the precious resource for granted.
Referring to the experience of other countries, Vahidi said Japan treats at least 345,000 cubic meters of greywater a year, of which 230,000 cubic meters are used for urban green spaces.
A subsidiary of the National Petrochemical Company, KPC is the largest chemical producer in northeast Iran. The complex has been producing urea, ammonia and melamine for over two decades.
