Title: Effects of membrane fouling and scaling on boron rejection by nanofiltration and reverse osmosis membrane
Journal: Desalination
Authors: Kha L. Tu, Allan R. Chivas, Long D. Nghiem
Corresponding author: Long D. Nghiem
The original and creativity of paper:
This paper presented the effects of membrane fouling on the rejection of boron by nanofiltration and reverse osmosis membranes.
Summary:
- Humic acid and alginate caused the highest decline in permeate flux and followed by colloidal silica and CaSo4 scaling.
- Humic acid was found to increase the efficiency of boron rejection. This is because the adsorption of humic acid on the membrane surface could increase negatively charge property of the membrane surface.
- Boron rejection can be reduced by the membrane charge neutralization which is the effect of the colloidal silica and CaSO4 scaling layer.
- The initial permeate flux and hydrophobicity of the foulant affected on the permeate flux decline.
- Membrane fouling can occur in two stages: foulant-membrane interaction and foulant-foulant interaction. At the first stage, the rapid decrease in permeate flux was found due to foulant-membrane interactions. Later, the foulant-foulant interaction, which caused less effect on permeate flux decline, was found.
- In the presence of Ca2+in feed solution, it could serve high impact on the permeate flux decline because of the complexation of Ca2+ and carboxylate functional groups of alginate molecules. Moreover, this complexation affected on thick and dense fouling layer
Application & further study: The findings are very meaningful for understanding of fouling mechanism during SWRO process.
By Monruedee Moonkhum
Email: moon@gist.ac.kr