Fouling analysis of ultrafiltration and nanofiltration membranes

Chemical and microbiological analyses were performed in an attempt to obtain a better understanding of the reduction of membrane fouling via the use of feed pretreatment. Biofiltration was chosen as pretreatment due to its potential to be a sustainable process coupled with membrane filtration. Biofiltration effectively reduced the concentration of organic and biological matter in the feed solution, decreasing the material deposited on the membrane surface approximately by half. More importantly, it reduced the loss of permeability during the operation of UF and NF membranes. However, it is believed that the performance of biofiltration as membrane pretreatment can be further improved with a greater understanding of the material that causes membrane fouling. This way the biofilter design and operation can be optimized to specifically minimize the concentration of this fouling material.