Removal of natural organic matter by ultrafiltration with TiO2-coated membrane under UV irradiation

Arie Dipareza Syafei, Cheng-Fang Lin, and Chung-Hsin Wuc

Department of Environmental Engineering, Sepuluh Nopember Institute of Technology, Surabaya, Indonesia
Graduate Institute of Environmental Engineering, National Taiwan University, Taipei, Taiwan
Department of Environmental Engineering, Da-Yeh University, Da-Tsuen, Chang-Hua, Taiwan

Abstract

This study investigates the performance of ultrafiltration (UF) by membranes coated with titanium dioxide (TiO2) photocatalyst under ultraviolet (UV) illumination in removing natural organic matter (NOM) and possibly in reducing membrane fouling. Experiments were carried out using heat-resistant ceramic disc UF membranes and humic acids as model substances representing naturally occurring organic matter. Membrane sizes of 1, 15, and 50 kDa were used to examine the effects of coating under ultraviolet irradiation. A commercial humic solution was subjected to UF fractionation (batch process); gel filtration chromatography was applied to study the effects of molecular weight distribution of NOM on UF membrane fouling. When compared to naked membranes, UV254 (ultraviolet light of λ=254 nm) illumination of TiO2-coated membranes exhibits more flux decline with similar effluent quality. Although the UF membrane is able to remove a significant amount of humic materials, the incorporated photocatalysis results in poor performance in terms of permeate flux. The TiO2-coated membrane under UV254 irradiation alters the molecular weight (MW) distribution of humic materials, reducing them to <1 kDa, which is smaller than the smallest (1-kDa) membrane in this study. Thus, TiO2-coated membranes under UV254 irradiation do not perform any better in removing natural organic matter and reducing membrane fouling.


Graphical abstract

With increased of attention towards ultrafiltration membranes in water treatment to remove natural organic matter, and it is aimed to examine the membrane performance by coating with TiO2. The effect of coating with TiO2 on membrane performance is examined. Figure: Scanning electron microscope microscopy of TiO2-coated membrane.



Keywords: Ultrafiltration; TiO2; Photocatalysis; Humic acid; Membrane fouling; Flux decline

Article Outline

1. Introduction
2. Materials and methods
2.1. Feed water
2.2. UF membrane system
2.3. Permeability
2.4. TiO2 coating
2.5. Molecular weight distribution
2.6. Analysis
3. Results and discussion
3.1. Flux performance
3.2. Removal characteristics
3.3. Molecular weight distribution
4. Summary
Acknowledgements
References

Journal of Colloid and Interface Science
Volume 323, Issue 1, 1 July 2008, Pages 112-119

Ya, tidak terlalu berpengaruh dilihat dari sisi properti humic acidnya yah.. Tp kalo pertanyaannya removal performance, sedikit ada perbaikan, walau tidak signifikan.