A numericalmodelwas established to predict and optimise the chemical cleaning process of Polyvinylidene Fluoride (PVDF) Ultrafiltration (UF) membraneswith the results fromthe experiment that applied the Response SurfaceMethod (RSM) and Central Composite Design (CCD). The factors considered in the experimental designwere sodium hydroxide (NaOH) concentration

sodium hypochlorite concentration (NaClO)

citric acid concentration and cleaning duration. The interactions between the factors were investigated with the numerical model. Humic acid (20 mg·L

-1

)was used as themodel foulant

and chemical enhanced backflush (CEB) was employed to simulate the chemical cleaning process. The concentrations of sodium hydroxide

sodium hypochlorite

citric acid and cleaning duration tested during the experiments were in the range of 0.1%-0.3%

100-300 mg·L

-1

1%-3% and 0.5-1.5 h

respectively. Among the variables

the sodium hypochlorite concentration and the cleaning duration showed a positive relationship involving the increased efficiency of the chemical cleaning. The chemical cleaning efficiency was hardly improved with increasing concentrations of sodium hydroxide. However

the data was sharply decreased when at a l

ow level of sodium hydroxide concentration. In total

54 sets of cleaning schemes with 80% to 100% cleaning efficiency were observed with the RSM model after calibration.