EghtesadOnline: Isfahan wastewater network will be linked via a 3000-meter pipeline to the sewage treatment unit of Isfahan Power Plant, in the eponymous central province, and save 5 million cubic meters of water annually, managing director of the provincial electric company said.
“Construction of the wastewater unit for the power station cost $3.3 million and is now ready to receive raw sewage for treatment,” Bargh News quoted Saeed Mohseni as saying. The output will be used by industries and farmers.
“The plant can produce 5 million cubic meters of treated wastewater per annum, a part of which will be sold to farmers along the Zayandehrud River (now almost dry) and the rest to cooling towers and steam units in the power plant,” he noted.
The facility will treat effluent produced in nearby cities, namely Khomeini Shahr and Dorcheh and help ease the water problems of farmers in the central plateau forever grappling with chronic water shortages.
River Drying Up
Isfahan Power Plant was designed to use wet cooling towers, the water for which in the past came from Zayandehrud River. However, it is facing serious challenges because the river’s water levels continue to recede and the plant must use treated wastewater.
Located in the southwest of Isfahan and on the banks of Zayandehroud River, it is a steam power plant with five units and 835 MW capacity.
A steam power plant consists of a boiler, steam turbine and generator, and other auxiliaries. The boiler generates steam at high pressure and high temperature. The steam turbine converts the heat energy of steam into mechanical energy. The generator then converts the mechanical energy into electric power.
Isfahan is located in an arid region with below minimum precipitation and like many other provinces has been struggling with drought for years resulting in the gradual drying up of the Zayandehrud River – once the pride of the region.
The river starts in the Zard-Kuh sub-range of the Zagros Mountains in Chaharmahal and Bakhtiari Province, flows 400 km eastward before ending in the Gavkhouni swamp, a seasonal salt lake, southeast of Isfahan.
It used to have significant water flow all year long in the past, but now mostly runs dry due to years of inadequate rainfall. Curbing water consumption is a compulsion, more so because Iran is grappling with fast disappearing underground water tables.
Environmentalists and experts say industries must soon shift to recycled water for heating and cooling instead of the scarce and costly potable water.
As per a directive issued by the Energy Ministry last year, it is mandatory for all thermal power plants to use reclaimed wastewater instead of potable water and water from wells, lakes and rivers in their cooling towers.
Reports say 222 wastewater treatment plants are operating in Iran and total sewage treatment capacity has surpassed 11 million cubic meters a day.
Over 66,000 km of wastewater pipelines have been laid across the country and 300 cities are connected to the rapidly expanding system.