Rosalam Sarbatly

A review of polymer nanofibres by electrospinning and their application in oil-water separation for cleaning up marine oil spills.

The growths of oil and gas exploration and production activities have increased environmental problems, such as oil spillage and the resulting pollution. The study of the methods for cleaning up oil spills is a critical issue to protect the environment. Various techniques are available to contain oil spills, but they are typically time consuming, energy inefficient and create secondary pollution. The use of a sorbent, such as a nanofibre sorbent, is a technique for controlling oil spills because of its good physical and oil sorption properties. This review discusses about the application of nanofibre sorbent for oil removal from water and its current developments. With their unique physical and mechanical properties coupled with their very high surface area and small pore sizes, nanofibre sorbents are alternative materials for cleaning up oil spills.

A Critical Review on the Spray Drying of Fruit Extract: Effect of Additives on Physicochemical Properties

Spray drying accomplishes drying while particles are suspended in the air and is one method in the family of suspended particle processing systems, along with fluid-bed drying, flash drying, spray granulation, spray agglomeration, spray reaction, spray cooling, and spray absorption. This drying process is unique because it involves both particle formation and drying. The present paper reviews spray drying of fruit extracts, such as acai, acerola pomace, gac, mango, orange, cactus pear, opuntia stricta fruit, watermelon, and durian, and the effects of additives on physicochemical properties such as antioxidant activity, total carotenoid content, lycopene and β-carotene content, hygroscopy, moisture content, volatile retention, stickiness, color, solubility, glass transition temperature, bulk density, rehydration, caking, appearance under electron microscopy, and X-ray powder diffraction. The literature clearly demonstrates that the effect of additives and encapsulation play a vital role in determining the physicochemical properties of fruit extract powder. The technical difficulties in spray drying of fruit extracts can be overcome by modifying the spray dryer design. It also reveals that spray drying is a novel technology for converting fruit extract into powder form.

Purification of Aquacultural Water: Conventional and New Membrane-based Techniques

Removing solids is an essential task when recirculating water an aquaculture system. Dissolved solids production directly from particulate solids as well as by fish is a function of time. These contaminants can indirectly affect the fish both biologically and physically. The flaws of conventional water treatment on seawater aquaculture systems are reviewed in this paper. Then a new technology for membrane processes is described to remove fine particles and dissolved matter in addition to performing gas transfer.

Kinetic and thermodynamic characteristics of seaweed dried in the convective air drier.

This study reveals the drying kinetics, specific heat and enthalpy of seaweed dried in the convective air drier. Comparison between convective hot air and sun drying process was also studied. At 50°C air temperature with 23.45 percent relative humidity and 1.55 ms-1air flow rate, it has been found that the moisture removal required 4 hours to reach moisture content of 19.66 percent wet basis with its drying rate at 0.28 x 10-3 kg water h-1. The data of drying rate showed that the drying process took place in the falling rate period. The specific heat and initial enthalpy were found to be 1.3842 kJkg-1°C-1 and 1672.69 kJkg-1, respectively. It was observed that the drying kinetics, specific heat, and enthalpy values vary significantly as functions of air temperature which seem to have more effect when compared to air flow rate and seaweed loading. Hence, the best method for seaweed drying was to use convective air system rather than sun drying because it required less drying time and has better drying efficiency.

Advances in biofuels

Prospect, Challenges and Opportunities on Biofuels in Malaysia.- Investment Opportunities at Palm Oil Industrial Cluster (POIC) Lahad Datu with Special Reference to Biofuels.- Biomass Conversion to Fuel (Solid, Liquid and Gas Fuel) .- On-line Mass Spectrometric Analysis of Sulfur Compounds From Hydrothermal Reactions of Biomass Wastes for Hydrogen Production.- Utilization of Oil Palm Wastes for Biofuel and Other Added Bioproducts: A Holistic Approach to Sustainable Waste Management for the Oil Palm Industry.- In-situ Spectroscopic Monitoring of Straight Vegetable Oils Combustion Properties (Sunflower and Soybean Oils) .- Low Cost Alternative Renewable Energy Bioethanol Production Palm Oil in Malaysian Context.- A bio- route production of biodiesel.- Catalysis in Biodiesel Synthesis: Challenges and Future Perspectives.- Higher Grade Biodiesel Production by Using Solid Heterogeneous Catalysts.- Enzymatic Process for Biodiesel And High Value Added Products.- Stability studies of immobilized Burkholderia cepacia lipase and its application in biodiesel production from Jatropha curcas oil.- Fermentation Study on Macroalgae Eucheuma Cottonii for Bioethanol Production via Varying Acid Hydrolysis.- Membrane Photobioreactor as a Device to Increase CO2 Mitigation by Microalgae

Membrane Photobioreactor as a Device to Increase CO2 Mitigation by Microalgae

The integration of a membrane contactor with a photobioreactor serves two major purposes for the mitigation of CO2 by microalgae, i.e., to enhance the mass transfer and interfacial contact between two different phases and to increase the exchange process of CO2–O2 by microalgae in the photobioreactor. The membrane integrated with a photobioreactor for CO2 mitigation by microalgae can be considered as a relatively new field, and only four or five related research efforts have been published in the literature, suggesting that a significant amount of work remains to be done in this field. In addition, all of the authors agreed that a membrane contactor is capable of achieving better mass transfer than the conventional approach of using a separation column in the gas–liquid separation process. One significant problem associated with using a membrane as a CO2–O2 gas exchanger is its susceptibility to pore fouling due to the micron-size cells of the microalgae. However, pore fouling can be prevented by using a hydrophobic membrane contactor and appropriate operating conditions, both of which are discussed in detail in this work.

Phytochemical Constituents and Activities of Morinda citrifolia L.

Both artificial and naturally occurring antioxidants have been reported to play major roles in protecting membranes and tissues from free radical and xenobiotic-induced oxidative damage (Burton, 1989; Carini et al., 1990). Most living organisms harbour both enzymatic and non-enzymatic systems that protect them against excessive reactive oxygen species. However, various external factors (smoke, diet, alcohol and some drugs) and aging decrease the efficiency of these protective systems, thereby disrupting the redox equilibrium that is established under healthy conditions. Thus, antioxidants that scavenge reactive oxygen species may be of great value in preventing the onset and propagation of oxidative diseases (Willet, 1994). Recently, more attention has been paid to the role of natural antioxidants, mainly phenolic compounds, which may have higher antioxidant activity than do conventional antioxidants, such as vitamins C, E and β-carotene (Vinson et al., 1995). The anti-oxidative effects of natural phenolic compounds, in pure form or in extracts from various plant sources (vegetables, fruits and medicinal plants), have been studied in vitro using a variety of model systems (Meyer et al., 1998; Pietta et al., 1998; Yen & Hsieh, 1998). Therefore, antioxidants, which can neutralize free radicals, may be of central importance in the prevention of carcinogenicity, cardiovascular disease and neurodegenerative changes associated with aging (Halliwell, 1994; Yu, 1994). Epidemiological studies have shown that the consumption of vegetables and fruits can protect humans against oxidative damage by inhibiting and/or quenching free radicals and reactive oxygen species (Ames et al., 1993).

Potential use of carbon dioxide by microalgae in Malaysia.

CO2 emission, which is feared to bring more harm than benefit to the environment, can be prevented and reduced through the cultivation of microalgae. Microalga is the fastest growing organism (estimated 40 times faster than terrestrial grass) and requires a high CO2 concentration to reproduce. Thus, this work evaluates the potential of microalgae to utilise CO2. The tolerable concentration of CO2 for high microalgae productivity as a biomass producer is also explored. High productivity of microalgae is the key to successful biofuel productions, that is, not only producing green energy but also preventing the release of CO2 into the atmosphere. Because of this concern, microalgae potential as a double-benefit for green energy production is analysed and discussed considering a CO2 emissions scenario in Malaysia.

Membrane Processes for Microalgae in Carbonation and Wastewater Treatment

The objective of this work is to present the integration of membrane processes in the field of bioenergy resource and wastewater treatment using microalgae. There are two main processes involved: carbonation and separation, which were conducted and reported as a separated work within this chapter. The chapter begins with the introduction of membrane processes, followed by carbonation of microalgae and separation of biomass from the wastewater effluent. The experimental work on the carbonation aims to evaluate the effectiveness of hydrophobic hollow fibre membrane in transporting CO2 into microalgae culture and microalgae accumulation within the membrane. The experimental work on the separation process of microalgae biomass from the wastewater effluent on the other hand, aims to evaluate Ultrafiltration (UF) membrane capability in removing BOD and COD as well as its ability to retain microalgae biomass which were used by the turbidity reading of the membrane permeate. The application of hydrophobic membrane in the carbonation process has increased the carbonation efficiency up to 83 % in comparison with the carbonation without membrane and only a small amount of mirage was accumulated within the membrane. The experimental result also shows that, the carbonised microalgae can be further used for wastewater treatment. Based on the result of separation process of microalgae biomass of wastewater effluent, the UF membrane utilization shows high separation efficiency in turbidity to lower than 5 Fau, and was able to facilitate in nutrient removal for less time required compared to the biological treatment without application of the membrane.

Spray Drying of Morinda Citrifolia L. and Beta Vulgaris L. Fruit Extract and Its Synergistic Effect

 Abstract—This study was to examine the antioxidant potential of Morindacitrifolia L. and Beta vulgaris L. fruits and its synergistic effect. The bioactive components of these fruits were extracted and then microencapsulated by spray drying technique. The antioxidant activities of these fruits were analyzed, before and after the spray drying process through DPPH radical scavenging activity, total phenolic content and total flavonoid content. The encapsulation yield of the spray drying process was also quantified. Among the spray drying samples encapsulation yield was found maximum 8 % for the mixed fruit extract. Similarly, synergistic effect between the two fruits showed the highest antioxidant activity of 30% and the individual fruit extract also exhibited significant antioxidant activity.