EghtesadOnline: To help reduce consumption of piped water across the sprawling capital, the second phase of a development plan to transfer sewage from the South Tehran Wastewater Treatment Complex to Tehran Oil Refinery is underway, head of engineering department of the refinery said.
“The plan calls for diverting 19 million cubic meters of wastewater a year to the refinery’s wastewater unit now under construction,” Reza Heydari was quoted as saying by ILNA.
When completed, 19 million cubic meters of piped water will be saved annually and pumped to small towns in the vicinity of the refinery in south Tehran, he added.
The wastewater, which will be recycled in the refinery’s wastewater treatment facility, will have a low total dissolved solids (TDS) that is suitable for cooling towers and the refinery’s fire department.
TDS is a measure of the dissolved combined content of all inorganic and organic substances present in a liquid in molecular, ionized, or micro-granular suspended form.
Referring to other advantages of treated sewage, Heydari noted that the wastewater plant of the oil refinery will supply boilers with demineralized water, water completely free (or almost free) of dissolved minerals, that can be used instead of boiler feedwater. BFW causes corrosion in the oil complex.
The wastewater treatment unit is under construction and seven kilometers of water pipes have been laid.
A 2015 agreement between TWWC and Tehran Refinery calls on the former toprovide the latter with 2 mcm of wastewater per annum for 30 years. This volume will increase as soon as the second phase of the project is completed.
While 48% of the country’s treated wastewater is used in the agricultural sector, about 45% of it enters surface waters, less than 0.5% is utilized by industrial units and 5% for urban green spaces.
Recalling that wastewater output is estimated at 1.2 billion cubic meters per year, Heydari said 70% of water used by households can and should be reused in wastewater treatment plants.
Unlike some countries, recycled wastewater is not used for drinking purposes in Iran as it is against Islamic tenets, the head of the department in charge of wastewater networks at the National Water and Wastewater Engineering Company, Behnam Vakili has said
Wastewater is largely used in the industrial and agricultural sectors, Vakili said, and added that since the 1960s when the first wastewater treatment plant was built in Iran, more than 200 plants have been built, of which 183 are operational and the rest will go on stream soon.