Microfiltration followed by desalination through reverse osmosis
Portland, New South Wales
Both 6 ML/d, Wallerawang upgradebale to 12 ML/d
Challenge While 'blow down' water from cooling towers at NSW electricity generator Delta Electricity's Mt Piper and Wallerawang power stations, has been collected, the volume of salts retained during the cooling process has made it unsuitable for reuse without treatment. Previously this water was disposed of through licensed and controlled discharge to the environment with fresh water being continually drawn from local rivers and dams to meet on-going process requirements. Delta Electricity sought to optimise its water usage through reuse.
Solution In joint venture with UGL, Osmoflo has designed and commissioned two 6 ML/d reverse osmosis plants to desalinate the collected blow down water and converted it to a quality suitable for reuse. Both plants have been constructed in modular form to allow for increased capacity if required. Pre-treatment is microfiltration. As a result of the reverse osmosis process, salinity is reduced from more than 3,000 mg/l Total Dissolved Solids (TDS) to less than 50 mg/l at Mt Piper and less than 200 mg/l at Wallerawang for reuse in cooling towers. Through an operations and maintenance contract, both plants are constantly monitored from Osmoflo's 24 hour control centre at Burton SA, utilising the company's proprietary PlantConnect system. This ensures optimum plant performance while eliminating the need for full time operators on site.
Result Delta Electricity's reliance on local water sources is now substantially reduced and discharges of blow down wastewater to the environment practically eliminated.
Delta Electricity is the largest capacity generator operating in the National Electricity Market with an installed capacity of more than 5,000 megawatts.