Cause analysis of fouling on ultrafiltration membrane in make up water treatment system of one power plant has been carried out.By using the conventional method and ICP spectroscopy technology

the composition of fouling has been analysed

the result shows the fouling is constituted from organic matters

silicon

and iron etc..Owing to the interaction between organic and inorganic matters

the difficulty of chemical cleaning is increased.A chemical cleaning test for a single membrane element has been carried out by using the method of off-line chemical cleaning

having good effectiveness.After chemical cleaning

the flow rate of water produced by a single membrane element has increased from 2~3 m3/h to 8~9 m3/h

the pressure on dense-water side being enhanced to about 0.08 MPa

the flow rate of effluent water from equipment of a complete set reaches 45~55 m3/h

the pressure difference of water between inlet and outlet is about 0.02 MPa

the turbidity of effluent water is zero

reaching basiscally to a state of new membrane.