421 m3/day Industrial Wastewater Treatment Plant, Sewerage Network and Waste Management System for Fauji Fresh n Freeze , Sahiwal

The 421 m3/day wastewater treatment plant comprising of (200 m3/day domestic wastewater + 221 m3/day process wastewater). The process wastewater flows initially from Upflow Anaerobic Sludge Blanket (UASB) reactor followed by activated sludge process. In UASB 70% of the influent COD is removed and around 160 m3/day bio gas is produced as by product. The domestic wastewater flows directly through the activated sludge process. The UASB is designed to handle upto 2500 mg/L influent COD. The treated water quality after secondary clarifier is COD < 70 mg/L which is well below Pak NEQS.

All sewage produced within the factory (domestic + process) is collected through pipe line (steel reinforced HDPE) and is brought to the wastewater treatment plant by a series of manholes.

We have also designed and constructed a salinity gradient solar pond: This pond can store the RO reject of 20 days. This pond operates on the principle that if RO reject is allowed to stay in the tank, salinity gradients are formed. Different salinity values in gradients can absorb different solar radiations and form heat gradients. The heat can be extracted from this pond using heat exchangers and this heat can be used to pre-heat the water for boiler or other applications in the process plant.