1.
Title
Preparation and Characterization of Modified Polyvinylidene Fluoride Membranes with Enhance Fouling Resistance for Refinery Wastewater Treatment.
2.
Introduction
Water has been and will continue to be a major factor of the survival of human and human activities that needs certain concern and protection. Because of the limited resources of fresh water, careful use and frequent reuse after appropriate treatment are requirements for sustainable development development and healthy life. As industrial development in the world, mostly in newly industrialized countries grew significantly, amounts of industrial wastewater have been drastically increasing each year. The amounts of heavy metals and synthesized organic compounds generated by industrial activities have increased and some 10,000 new organic compounds are added each year. Nevertheless, these compounds are complex, difficult and costly to treat by conventional wastewater treatment processes. For example, wastes from manufacturing plants contribute to pollution generation and environmental degradation e.g. textile, semiconductor, palm oil mill and rubber processing plants (Sairan and Ujang, 2004). Industrial wastewater treatment is a group of unit processes designed to separated, modify, remove and destroy undesirable substances carried by wastewater from industrial sources from industrial sources. Industrial wastewater treatment cover the mechanism and processes use to treat water that have been contaminated in some way by anthropogenic industry.
3.
Literature Review
Ultrafiltration membrane using porous membrane to separate pure water and microsolutes is an alternative for industrial wastewater treatment (Jung, 2004). Ultrafiltration
(UF) is cost effective as compared to reverse osmosis and nanofiltration. With production of high quality water effluent, ultrafiltration is an attractive way due to its compactness, easy automation as well as superior removal of turbidity (Gao
et al.,
2011).
UF is classified as low pressure membrane filtration with limi ted pore size range from 10 A to 1000 A. Under a trans-membrane pressure, source of wastewater will pass through the filter and retain unwanted solute. UF has drawn special attention as compared to other conventional method as it required low capital and operating cost and without the use of chemical (Gao et al., 2011).
Even though UF has been used widely in many areas especially in water treatment, certain issues are still need to be developed further for a better performance of UF membrane. Many researchers have worked on novel UF membrane to integrate superior UF performance such as higher removal of contaminants, slower rate of losing permeability and low operating cost (Gao
et al.,
2011). In addition, Asymmetric hollow membranes are often choosing for
separation process as it offers high selectivity of dense membrane and high permeation rate. There are several ways to modify asymmetric hollow fiber membranes in order to integrate better membrane performance such as dip-coating, additive addition, heat treatment, blending, cross-linking and grafting (Tsai
et al.,
2011).
Choice of polymer is an important aspect that would determine separation performance of UF membrane. Polyvinylidene fluoride (PVDF) UF membrane had been used widely in conventional UF membrane because of its good properties in chemical and thermal stability and solvent resistance. PVDF has received great attention as a membrane material with regard to its outstanding properties such as high mechanical strength, thermal stability,
chemical resistance and high hydrophobicity, compared to other commercialized polymetric materials. PVDF membranes have been extensively applied in UF and MF for general separation purpose and are currently being explored as potential candidates in the applications of membrane contractor and membrane distillation.
Interfacial interaction between nanoparticles and polymer matrix properties of water feed are also crucial to determine final separation performance of UF membrane. As compared to pure polymer membrane, nanocomposite membrane proved to integrate greater permeability and selectivity. Nano particles such as carbon nanotubes (CNTs) seem to be an attractive and promising way for superior permeability and high selectivity (Ge
et al.,
2011).
Since the discovery of CNTs in late 1991, CNTs has been considered to be added to polymeric materials due to attractive mechanical, thermal and electrical properties of CNTs. It has been proved that low concentration of CNTs lead to significant increase of mechanical strength of polymer materials (Cong
4.
et al.,
2007).
Objective of the Research
In order to further develop UF membranes, the objectives of this study are listed as follow:
i.
To synthesize and fabricate the asymmetric hollow fiber UF membrane with improved performance.
ii.
To develop and characterize hollow fiber UF membrane in order to fabricate high flux membranes with improved performance.
iii.
To study the effect of the CNTs and the preparation conditions on the membrane structure.
iv.
To investigate the interaction between polymer and copolymer and to evaluate longterm stability of the UF membrane and membrane lifetime.
v. vi.
5.
To characterize and evaluate energy efficient. To characterize membrane performance based on permeability and selectivity.
Research Methodology
This research will fabricate asymmetric hollow fiber membrane by using PVDF polymer with combination of SPEEK as copolymer in order to increase hydrophilicity of the UF membrane. Apart from that, CNTs will be added as an additive to increase mechanical strength of the membrane as well as to improve permeability and selectivity. Different concentration of PVDF, SPEEK and CNTs will be tested during membrane fabrication until it meets high separation performance of UF membrane. UF membrane will be further characterized by FESEM, AFM, TGA and NMR in order to evaluate physical stability of the membrane. Moreover, the performance of the membrane will be investigated by permeability test.
MATERIAL SELECTION (polymer, additive, copolymer)
Membrane casting procedure Dope formulation Post treatment
PREPARATION OF HOLLOW FIBER MEMBRANE
MEMBRANE CHARACTERIZATION
FESEM examination AFM examination TGA examination SEM examination
MEMBRANE PERFORMANCE
Permeability test Long term stability test Study effect of preparation condition
Study on fouling susceptibility
6.
Hypotheses
From this research, it is expected to produce hollow fiber UF membrane with improved performance. Since, fouling is one of the big challenges in membrane technologies, this research is initiated to study high performance membrane for energy efficient in industrial wastewater treatment. Apart from that, this membrane system is predicted to have greater efficiency in chromium removal from industrial wastewater.
7.
Gantt Chart of Research Activities
The Gantt chart of the research and milestones are given in Table 1.
No.
Research Activities
Q1
Q2
Q3
Q4
YEAR ONE 1
Q1
Q2
Q3
Q4
YEAR TWO
Literature review. To review the recent development of asymmetric hollow fiber UF membrane
2
Preparati on of UF membranes To fabricate hollow fiber UF membrane To study effect copolymer addition To study effect of CNTs addition To study the membrane structure and chemistry on polyamidepolysulfone composite membranes
3
Characteri zation of the fabricated membranes To characterize the membrane structure To investigate the effect of additives and preparation conditions on membrane structure
4
Membrane performance test To investigate long-term performance and stability To optimized the membrane performance particularly in fouling resistant
5
Publication To submit papers in international journal
milestone
8. Expected Results
The expected results of this research are given as follow: I.
To achieve new finding in designing more robust asymmetric hollow fiber membranes with improved performance that could result in additional reductions in chromium removal
II.
To identify the morphology and chemistry of membrane structure which may influence membrane performance
III.
To optimized the operating conditions of UF system specifically in energy recovery in order to reduce the energy consumption of UF water treatment process.
9.
Conclusion
8. Expected Results
The expected results of this research are given as follow: I.
To achieve new finding in designing more robust asymmetric hollow fiber membranes with improved performance that could result in additional reductions in chromium removal
II.
To identify the morphology and chemistry of membrane structure which may influence membrane performance
III.
To optimized the operating conditions of UF system specifically in energy recovery in order to reduce the energy consumption of UF water treatment process.
9.
Conclusion
Industrial wastewater has introduced wide range of toxic chemical to water system. Without proper management of wastewater, it would be harmful to human as well as environment. Many technologies have been developed to overcome this issue. However, certain technology not efficient enough to manage wastewater and required a lot of money. With the increasing population in the country, demand of water will be higher. Thus, development of high performance UF membrane for wastewater treatment i s required to meet water quality. Furthermore, since UF membrane has been applied in many industrial wastewater treatment, it is seems to be promising alternative to be developed further to achieve greater separation performance. Further optimization and development of high flux UF membranes and the development of innovative energy recovery system are still needed in
the years to come in order to discover a more energy-efficient approach and to improve membrane stability, particularly against fouling.
10.
References
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chromium ions from solutions containing obstructive copper ions , J. Desalination 274 (2011) 246-254.
Susanto H. and Ulbricht M., Characteristics, performance and stability of polyethersulfone ultrafiltration membranes prepared by phase separation method using different macromolecular additives, J. Membrane Science 327 (2009) 125-135. Tsai A-A., Yeb Y-L., Lee K-R., Huang S-H., Suen M-C., Lai J-Y., Characterization and pervaporation dehydration of heat-treatment PAN hollow fiber membranes, J. Membrane Science 368 (2011) 254-263.