The city of Ahwaz Wastewater treatment plant

Location: The Eastern part of Ahwaz city

Capacity: 120,000m3/day

Employer: Ahwaz water and waste water company

Supervisor: P2m berlin Gmbh

Date of starting: 2009

The city of Ahwaz Wastewater treatment plant

Brief specification of treatment process

The proposed system for treating wastewater in Eastern Ahwaz includes:

Preliminary Treatments units
This includes screening devices and de-gritting facilities. Objects collected from screens are transferred to the compactor,via a screw conveyor. Three screens are to be used in this WWTP, of which one is on standby. Following the screening equipment are the grit-hambers.Settled grit is discharged out of the chamber by a pump which is moving along with the travelling bridge. Collected sand is then washed and dewatered toremove any associated organic matter. For Ahwaz WWTP, there are three grit chambers, including one on stand-by.

Biological Treatment
This will be attained using sequencing batch reactors (SBRs). Advantages of SBRs in comparison to conventional activated sludge include elimination of finalclarifiers and return sludge pumping (thus reduced capital investment), ease in making operational changes to fine-tune nutrient removal, ability to hold andtest treated wastewater before release, easily expandable by placing additional tanks in parallel and ability to handle variable hydraulic and organic loadings.

Tertiary Treatment
Serves as a polishing step before the water is discharged out of the WWTP. This is achieved via ultra-violet (UV) disinfection step.

Sludge Dewatering
The sludge is collected into a storage tank and is fed to a combi system for thickening and dewatering. This step greatly reduces thevolume of the sludge by removing a significant amount of water, hence aiding the transport of sludge to the final destination.