Glucose production in the ultrafiltration system and cell-free xanthan gum production

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Effects of Modifier Polarity on Extraction of Limonene from Citrus Sinensis L.Osbeck Using Supercritical Carbon Dioxide

Limonene constitutes 98% of the essential oil obtained from orange peel. Besides being used as fragrances and flavours in the food, perfume and cosmetic industries, limonene is also a good degreasing agent. Supercritical carbon dioxide is an excellent solvent for non-polar compound like limonene but poor solvent for polar compound like α-terpineol. Common practice in supercritical fluid extraction is to change the polarity of supercritical carbon dioxide by employing polar modifiers to increase its solvating power towards polar analytes. Base on this, in the attempt to extract more limonene in orange essential oil, less polar modifiers were added instead. In this study, effects of adding modifiers with different polarity on extraction of aroma compounds (limonene, linalool and α-terpineol) from Citrus Sinensis L. Osbeck or sweet orange peel were investigated. Supercritical extraction was carried out at defined pressure and temperature for duration of 45 minutes. Concentration of aroma compounds extracted was analysed using GC-MS. The optimum conditions for extraction were observed at 318K and 12MPa. The concentrations of limonene increased significantly by the addition of methanol and slightly with n-heptane. It was also found that n-heptane is effective on supercritical CO2 extractions of linalool and α-terpineol

Coagulation/flocculation of anaerobically treated palm oil mill effluent (AnPOME): A review

Inefficiency of palm oil mill effluent (POME) treatment cause considerable environmental problems including from aesthetic point of view and inhibits the growth of the desirable aquatic biota necessary for surface water self-purification. Due to its low operating cost, anaerobic digestion of palm oil mill effluent (POME) is widely accepted by the managers, yet the colour of treated effluent (AnPOME) turned to dark brown. In this paper, the colourants in the AnPOME and its possible treatments have been reviewed with greater emphasis was put on coagulation/flocculation method. Application of anionic polymer as pre-treatment for integrated system has been shown to be necessary for sustainable AnPOME treatment including its sludge disposal. © Springer Science+Business Media New York 2013

Lignin removal from Aqueous Solution using Calcium Lactate: the effect of Polymers and Magnesium Hydroxide as a Flocculant aids

Palm oil mill effluent (POME) which is mainly associated with lignin has becoming a major concern due to its highly coloured appearance. The main colourant, i.e. lignin particles are difficult to be degraded in oil palm conventional biological ponding system. Coagulation/flocculation could remove the lignin prior to biological treatment and is considered vital to minimize the recalcitrance nature of palm oil mill effluent particles. In this study, the coagulation/flocculation process was investigated to remove lignin particles from aqueous solution. A non-toxic and biodegradable chemical i.e. calcium lactate was utilized as a destabilizer for the removal of lignin with an addition of several flocculants aid i.e. anionic polyacrylamide (APAM), polydimethyldiallylammonium chloride (polyDADMAC) and magnesium hydroxide. The effect of coagulant and flocculant aids dosage was investigated. From this study, it was found that the optimum condition was at 0.7g/L of calcium lactate and 0.5-1.0mg/L of APAM with ~64% of lignin removal. At concentration of 4 mg/L, the removal of lignin for APAM and polyDADMAC is similar. This result shows that the calcium lactate has potential as a coagulant and the efficiency can be enhanced with an addition of polymeric flocculant aids

Removal of oil and reduction of bod from palm oil mill effluent (POME) using polyurethane nanofibers

The effluent of the palm oil mill is known as palm oil mill effluent (POME) constituting water, oil and solid. Upon discharge from the mill, POME goes into an anaerobic pond system which is not environmentally friendly. The threats, mainly come from the accumulated oil inside the pond. Therefore, this study attempt to find a solution for this problem by using polyurethane nanofiber to sorb the oil from the POME due to its oleophilic and hydrophobic properties. The nanofibers were characterized by scanning electron microscopy (SEM), oil sorption capacity, amount of extracted oil of POME and Biological Oxygen Demand (BOD) content after sorption. The result shows the nanofibers average diameter is 3.0 103 nm, about 31.40 g /g oil sorption capacity, 48 % oil extracted from the POME and the BOD content was reduced to 10 mg/l. This result shows that nanofiber sorbent is a viable method to not only protect the environment, but also has the potential for recovery the oil

An Overview of Recent Progress in Nanofiber Membranes for Oily Wastewater Treatment

Oil separation from water becomes a challenging issue in industries, especially when large volumes of stable oil/water emulsion are discharged. The present short review offers an overview of the recent developments in the nanofiber membranes used in oily wastewater treatment. This review notes that nanofiber membranes can efficiently separate the free-floating oil, dispersed oil and emulsified oil droplets. The highly interconnected pore structure nanofiber membrane and its modified wettability can enhance the permeation flux and reduce the fouling. The nanofiber membrane is an efficient separator for liquid–liquid with different densities, which can act as a rejector of either oil or water and a coalescer of oil droplets. The present paper focuses on nanofiber membranes’ production techniques, nanofiber membranes’ modification for flux and separation efficiency improvement, and the future direction of research, especially for practical developments