The percent contribution of pH was negligible, indicating that
there are no significant differences between the three pH levels
tested on the membrane fouling. The orders of percent contribution are as follows, in decreasing order for response parameter:
transmembrane pressure>temperature>VRF. While transmembrane pressure has the highest percent contribution, VRF shows
very little effect on membrane fouling. This result indicates that
membrane fouling was mainly influenced by the transmembrane
pressure. The possible reason for the little effect of VRF could
attribute to lower range of VRF.