Waste Water Recycling for use in cooling towers open circuit cooling systems

Water is a resource that has been taken for granted for decades but is now a critical focal point for many companies and communities as the earth faces a water crisis.

It has been estimated that only 2.5 percent of the world’s water is freshwater, and of that, only 1 percent is accessible. As a result, only a tiny fraction of the planet’s water is available for everyday use. By one estimate, global freshwater demand will exceed supply by a staggering 40 percent in 2030 if current trends continue.

Businesses are beginning to look at their impact on the environment and assess how their operations affect the communities they operate in. By reducing their source water requirements, companies of any size can do their part to reduce environmental impact, while reinforcing their corporate social responsibility. Many companies also realize substantial cost savings from water-related investments.

Prime Chemicals Corporation and our client in the FMGC sector implemented a project to route 150 m3/day permeate (BOD < 15 mg/l, TSS < 5 mg/l, TDS 700 mg/l) from MBR wastewater treatment plant as make-up for cooling towers’ cooling water.

Industry: FMGC

Application: Recycled Waste Water

Location: Karachi

Challenge: Recycling wastewater for beneficial use

With eight round-the-clock functional cooling towers at different locations within the client premises, the water requirement closely matched the recycled water availability. The water quality, after chemical treatment, also matched the cooling tower’s requirement with Cycles of Concentration on the order of 2—3. Any excess water was routed for use as utility water and gardening purposes.

Additional to the MBR WWTP, the project included a thorough piping network, pumping system, and flow metering and control, and entails a source water saving of around 150,000 liters of water per day.

Apart from the economics, the project outlines a shift in focus towards social responsibility and water stewardship