The El-Nino phenomenon in early 2014 contributed to the lack of water supply in most Southeast Asian countries.
Suggestions have since been made to ensure the continuity of water supply, one of which involves membrane technology
to treat mine water so that it is compatible for citizens’ use. Accordingly, the objective of this research was to study the
efficiency of membrane technology in treating mine water. Our elucidation of all the parameters has showed that the
best attainable classification is at Class IV. Although it was still regarded as polluted, the treated mine water can be
used as water supply reservoir. For the membranes tested such as ultrafiltration 10 kDa, 5 kDa and reverse osmosis,
the percentage of rejection for chemical oxygen demand is 21-72%, 40-96% for total suspended solids and 21-72% for
ammonia nitrogen. The pH also gradually shifted to almost neutral after the filtration.
Membrane fouling caused by the adsorption of fatty acids limits the application of membrane technology in oleochemical industry especially for the pretreatment of glycerin-rich solution. The aim of the work presented in this paper was to understand the adsorptive fouling of palm oil based fatty acid on ultrafiltration membranes. The influence of solution pH, molecular weight cut-off (MWCO) and hydrophobicity of the membrane were studied. Oleic acid was used as a foulant, representing the long chain palm oil based fatty acid in glycerol−water solution. The outer membrane exposed to the mixtures for 6 h without pressure. The stirring speed was set at 300 rpm and polyethersulfone (PES) membranes with MWCO of 5, 20 and 25 kDa were used. The adsorptive fouling was determined using the relative flux reduction (RFR) method. It is demonstrated in this study that PES membranes are susceptible to the deposition of fatty acids on the membrane surface and pores. The fouling phenomenon at low pH is more severe than that of high pH due to the attractive force between solutes and the membrane. The PES membranes after adsorption were characterized by contact angle and Fourier transform infrared (FTIR), while the surface was visualized with scanning electron microscopy (SEM).
This study was aimed to investigate the effect of ZnO-decorated GO nanocomposite material loaded with different weight
percent of ZnO toward polysulfone (PSF) mixed-matrix membrane (MMM) performance enhancement. ZnO-decorated
GO nanocomposite material was loaded with 1, 5, 10 and 20 wt. % ZnO was blended with PSF polymer and fabricated
through phase inversion process. The performance of the fabricated MMMs were evaluated by measuring membrane
permeability, bovine serum albumin rejection (BSA) and flux recovery ratio (FRR). Experiment results demonstrated
that the PSF/ZnO-GO MMM performances were greatly improved where 10 wt. % ZnO loaded into ZnO-decorated GO
nanomaterial exhibited the highest permeability (5.35 L/m2
·h·bar) and BSA retention at all pH state among all fabricated
mixed-matrix membranes. Additionally, FRR was also dramatically improved attributed to the smoother membrane surface.
This work has shown that a well distribution of ZnO with the help of GO nanosheet as a dispersing agent blended with
PSF polymer to form PSF/ZnO-GO MMM was a promising approach in creating better ultrafiltration (UF) membrane with
a better hydrophilicity, permeability, and cleaning efficiency for the used in food industry in future.
Atomic force microscopy (AFM) has a wide range of applications and is rapidly growing in research and development. This powerful technique has been used to visualize surfaces both in liquid or gas media. It has been considered as an effective tool to investigate the surface structure for its ability to generate high-resolution 3D images at a subnanometer range without sample pretreatment. In this paper, the use of AFM to characterize the membrane roughness is presented for commercial and self-prepared membranes for specific applications. Surface roughness has been regarded as one of the most important surface properties, and has significant effect in membrane permeability and fouling behaviour. Several scan areas were used to compare surface roughness for different membrane samples. Characterization of the surfaces was achieved by measuring the average roughness (Ra) and root mean square roughness (Rrms) of the membrane. AFM image shows that the membrane surface was composed entirely of peaks and valleys. Surface roughness is substantially greater for commercial available hydrophobic membranes, in contrast to self-prepared membranes. This study also shows that foulants deposited on membrane surface would increase the membrane roughness.
Palm oil mill effluent (POME) treatment has developed in the last decade. Due to the characteristic and volume of POME,
it needed a complete treatment to reduce the pollutant content. Three pre-treatments method, ultrafiltration, adsorption
and decantation were applied prior to nanofiltration (NF) membrane. The polyethersulphone membrane, montmorillonite
as the adsorbent and modern decanter was investigated in this research. Two types of NF membrane, named NF-1 and
NF-ASP30 were used after pre-treatment. The removal of four important parameters were determined i.e. COD, TSS, colour
and turbidity. The results showed that the adsorption and UF is better than decantation pre-treatment. The ultrafiltration
and adsorption can reduce POME content more than 80% for all parameter while decantation varied between 40 and 80%.
The combination of ultrafiltration and adsorption with both of NF membrane can removed almost all the parameter. But
the decantation can only remove the turbidity but not for the rest of the parameters. Besides the POME content, the flux
decline for both of NF membrane was also investigated. The flux of NF-1 membrane was higher than NF-ASP30 membrane
but NF-ASP was more relative stable for the flux decline. Overall, NF-1 has better performance in flux decline.