Seawater to drink and for iron ore
Since 2004 one of the largest and most important freight harbours in North-East China has boasted a state-of-the-art extension. Iron ore imported from Australia arrives here to supply China's flourishing steel industry.
Over a thousand m3 of water are needed here every day to ensure that the 200,000 tonnes of ore can be unloaded dust-free and to supply the workers at the harbour with drinking water and water for washing, etc. The water should be drinking water quality, on account of the purity of the raw material. Chinese experts from the ProMinent group which is headquartered in Heidelberg planned, designed and constructed a complete solution for water treatment. The harbour operators are able to extract high quality drinking water exceeding the WHO standard from the endless supply of the salty Pacific bay. This ecologically and commercially sound solution means that the harbour does not need to be connected to the public drinking water network, thus avoiding a costly and complex undertaking.
The seawater treatment in Dalian’s iron ore harbour is essentially based on the principle of reverse osmosis. This tried and tested desalination technique works under pressure and with special membranes. No chemicals are required. The Dalian project was nonetheless a particular challenge for the experts in water treatment. The scope and complexity of this task embraced all phases, from planning to designing and constructing of all the necessary plants up to their operation around the clock.
The water passes through sand and activated carbon filters with integrated fully automatic backwashing and chemical pre-treatment before the reverse osmosis process. Energy is recovered to reduce overall consumption. A part of the drinking water prepared in this way is bottled. To ensure that it is free of bacteria in the long term, it is disinfected with ozone and passed through a second reverse osmosis unit.
Seven ProMinent technicians operate the water plant by using a control system that integrates all parts of the plant. The water treatment plant at the new iron ore harbour in Dalian has been running like clockwork 24 hours a day for the past six months now.
