Showing papers in "The Malaysian Journal of Analytical Sciences in 2017"

A review of oilfield wastewater treatment using membrane filtration over conventional technology

Abstract: The oil and gas industry has been a constant developing industry as it is of importance to the maintenance of industrial civilization in its current configuration and play vital roles in many other industries. Some oil and gas industry operations have been accountable of water contamination through by-results of refining and oil slicks. One of the biggest by-products that have raised a critical environment concern is oilfield produced water. Oilfield produced water (OPW) is coproduced aqua liquid phase which originate from well alongside oil phases in normal production process. The content of OPW consists of different type of organic and inorganic mix. Discarding this kind of wastewater can lead to surface pollution especially on water sources as well as soil. Hence, to meet environmental regulations as well as reuse and recycling of produced water, many researchers have focused on treating oily saline produced water. Conventional technologies used to treat produced water consist of clarifiers, dissolved air flotation, hydro cyclones, and disposable filters/absorbers. Typically, additional chemicals for coagulation or settling are needed which are expensive and are incapable of achieving recently required standards of cleanliness. Therefore, researchers have swung to membrane filtration plans because of their capability to minimize extra expenses and surpass issues connected with current advances. Thus, the purpose of this review is to highlight the current and developed membrane technology used in treating the oilfield produced wastewater and its current progress.

Pengekstrakan dan pencirian selulosa daripada bahan buangan pertanian - Pelepah kelapa sawit

Abstract: Cellulose from oil palm fronds (OPF) was extracted using a cost-effective method combining physical treatment (high pressure steaming) and repeated chemical treatments (alkali and bleaching). Alkali and bleaching treatments were performed using low concentrations of sodium hydroxide and sodium chlorite, respectively. High levels of cellulose were successfully extracted, with 4 grams of cellulose for every 10 grams of raw oil palm fronds. The morphology of the cellulose was investigated using variable pressure scanning electron microscope (VPSEM). Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analyser (TGA) were used for structural analysis. The extracted cellulose was found to have smaller diameter (8 – 10 μm) and smoother surface compared to the untreated fibres. The results from FTIR, XRD and TGA indicate that the hemicelluloses and lignin were extensively removed from the isolated cellulose. Alkali treatment helped in removal of hemicelluloses, while bleaching assisted in delignification. The extracted cellulose showed high crystalline index of 68.75% and degradation temperature of 350 C resulted from removal of lignin and hemicelluloses via alkali and bleaching treatments.

(Penyingkiran besi dan mangan oleh membran penurasan-nano dan penurasan-ultra: Pengaruh pelarasan pH)

Abstract: Iron and manganese present naturally in groundwater. Both metallic ions at excessive amounts normally contribute to rusty taste and reddish color to the water. Membrane technology may improve the conventional groundwater treatment method which commonly requires a large area and a lot of manpower. The present experimental work focused on membrane filtration of iron and manganese in order to study the influence of pH adjustment to the prepared artificial groundwater based on the permeate quality and membrane performances. In this study, two commercially available polyamide nanofiltration and ultrafiltration membranes (PA-NF, PA-UF) were tested to examine their capabilities in treating groundwater for drinking water resources. In order to achieve WHO drinking water standard, permeate quality of the artificial groundwater is considered satisfy if concentration of iron and manganese has reached 0.3 and 0.1 mg/L, respectively. Experimental results showed that pH at a range of 3-11 have significantly improved membrane performance in terms of their rejection. Rejection of iron at a feed concentration of 100 mg/L increased as pH of the feed solution increased for all tested membranes. However, the manganese rejection with a feed concentration at 50 mg/L showed various pattern of performance for each membrane. The pH of feed solution played an important role in changing the membrane surface properties and also, the characteristic of solute. This concludes that solutemembrane interaction mechanism has improved the performance of the tested membranes.

Cellulose nanocrystals with enhanced thermal stability reinforced thermoplastic polyurethane

Abstract: Melt compounding processing approach for incorporating cellulose nanocrystals (CNC) into thermoplastic polyurethane (TPU) has not well been explored. This is primarily due to the poor thermal stability and dispersibility of CNCs. As they are typically obtained from sulphuric acid hydrolysis, they give rise to degradation and discolouration of the extruded nanocomposites. The investigation of this research demonstrates sulphuric acid hydrolysis (CNC-S), phosphoric acid hydrolysis (CNC-P) and a novel non-hydrolytic high energy bead milling method (CNC-MC) into a polyether based thermoplastic polyurethane via melt compounding using twin screw extruder. The TPU film incorporated with CNC-S obviously shows the sign of CNC degradation where TPU film was changed to brown colour. The tensile strength of TPU reinforced with CNC-S, CNC-P and CNC-MC shows 18%, 16% and 14% of improvement at CNC loading of 0 to 1 wt.% upon host polymer. CNCs isolated via mild acid hydrolysis and mechanical milling methods, can be easily processed via large scale melt-processing techniques for reinforcing thermoplastic polyurethane without affecting their physical appearance and elastic properties.

Nanoemulsi berasaskan olein sawit sebagai pembawa vitamin E

Abstract: Aging process makes our skin getting thinner and drier. Antioxidant based on nanoemulsion system is favourable because of its effectiveness. This study was conducted to develop nanoemulsion system based on palm olein as a carrier of vitamin E and the physicochemical behaviours of the system were studied. Palm olein as oil phase, polyoxyethylene (4) lauryl ether (Brij 30) was used as a surfactant and vitamin E as an anti-aging agent. The mixtures of Brij 30 and palm olein at certain ratios were thoroughly mixed and titrated with 5 – 95% wt. of water and homogenized by using homogenizer. The Palm olein/Brij 30/Water mixtures that produced a clear solution and no birefringence after observation under polarized light microscopy are labelled as nanoemulsion. Nanoemulsion region was shown in ternary phase diagram. Based on the ternary diagram, these systems were formed at oil: surfactant (O/S) ratio 4:6, 5:5 and 6:4 and 20 – 50% wt of water. These systems were then characterized for stability test, particle size, electrical conductivity, viscosity and pH. Stability test was done at three temperatures, which were 4, 25 and 40 °C for one month and four cycles of freeze-thaw at storage temperature for 12 hours at each temperature. The systems were stable and no phase separation was observed. Particle size analysis showed that most systems have a particle size within the range of nanoemulsion (20 – 500 nm). Electrical conductivity tests showed that water-in-oil system formed at low water percentage (20 – 30% wt. of water) and bicontinuous at a higher percentage (30 – 50% wt. of water). Viscosity of both systems vitamin E-loaded and unloaded is very low. All systems have a pH value in a range of 6 – 7, which are suitable to be applied to human skin. Based on the physical characteristics of the system, it shows high potential as a vitamin E carrier.