1. Profile

(1) Project site:

Sohar, Oman.

(2) Owner:

SOHAR Steel Mill in Oman.

(3) Investment, construction and operation:

It was invested and operated by the Owner, designed and supplied by MCC Huatian Engineering & Technology Co., Ltd., and built by the local construction units from Sujar, Oman.

(4) Date of operation:

July 2015.

(5) Capacity:

8,209m³/h wastewater treatment.

2. Major environmental problems to be addressed

By increasing the circulation rate of the circulating water system, the consumption of new water production is reduced, local water resources are saved, and pollution of sewage to local surface water and groundwater is avoided.

3. Environmental standards and/or main index limits to be followed

For the production water system, Discharge Standard of Water Pollutants for Iron and Steel Industry (GB 13456-2012) and Code for Design of Industrial Recirculating Cooling Water Treatment (GB 50050-2007) shall be followed. The limits of main discharge indicators of production wastewater include: pH 6~9, SS≤30 mg/L, COD_cr≤50 mg/L, ammonia-nitrogen≤5 mg/L, total nitrogen≤15 mg/L, total phosphorus≤0.5 mg/L, petroleum pollutant≤3 mg/L, etc.

4. Technological process

Process flow of purified circulating water system: circulating water → user use → cooling tower → pool → pump pressurization → recycling.

Process flow of turbid circulating water system: circulating water → user use → primary sedimentation tank → pump pressurization → rare earth magnetic disc sewage treatment plant → pump pressurization → cooling tower → pool → pump pressurization → recycling.

5. Environmental pollution control effects

The circulation rate of circulating water system reached 98.8%, for the influent of turbid circulating water, SS≤300 mg/L, petroleum pollutant≤50 mg/L and about 48℃; for the effluent, SS≤50 mg/L, petroleum pollutant≤3 mg/L and about 38℃.

6. Social benefits

The project solved the problem of wastewater discharge for the Owner and achieved recycling of water resources.

7. Economic benefits

The circulating rate of the circulating water system reached 98.8%, saving about 1.1 million tons of new water every year.

Project significance: The project provides water supply and drainage system for the production lines of SOHAR Steel Mill with advanced, proven and reliable technologies and high-quality equipment, and has established a good reputation in Oman, providing successful experience for operation and implementation of overseas projects in the future, especially in the Middle East.