The zero wastewater discharging system in a power plant with air-cooled units situated in Northern China adopts a wastewater treatment process as in the following:air floation for oil removalwater softening using limegravity filter tankwater softening by ion exchangereverse osmosis.The technological process has been briefly presented

and the performance test of main treatment equipments being carried out.The results of test show that the quality indices of effluent water from said zero discharging system reaches the requirement of design

however

the self-using water for water softening system with ion exchange is 7.03%

being higher than the designed value of≤5%.In addition

the reverse osmosis facility uses membrane with highest desalting rate at pH value 6~8

making the chemical cleaning to be more frequent.