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

The effects of kaolin/PESF ratios on the microstructures of kaolin hollow tubes

The effects of kaolin/polyethersulfone (PESf) (k/p) ratios on the microstructures of kaolin hollow tubes have been investigated. Kaolin suspension containing k/p ratios between 1 and 3.5 was used to spin kaolin hollow-tube precursors via a dry-jet wet spinning method at 0-cm air gap. The cross-sectional microstructures of the kaolin hollow-tube precursors were investigated using scanning electron microscopy (SEM). The results show that, at k/p ratios of 1.0, 1.5 and 2.5 (low viscosity) and k/p ratios of 3.0 and 3.5 (high viscosity), the finger like voids dominated the outer regions and inner regions of the cross sections of the kaolin hollow tubes, respectivel

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

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

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Rheological properties of kaolin/PolyetherSulfone (PESf) used in hollow fiber fabrication: Effects of content ratio

In the present work, the rheological properties in terms of shear stress and viscosity of Kaolin/Polyether-Sulfone (PESf) of varying ratio were investigated by a rotating rheometer. The shear rate of Kaolin/PESf sample was measured at increasing interval shear rate. By assuming that the fluid behaves like a typical Non-newtonian polymeric liquid, the consistency index, K and flow index, n were able to be determined. Thus, the rheology behaviors of the kaolin/PESf suspension could be investigated at a wider range of shear rate. The shear stress was found to increase with increasing shear rate, with the rate of change quite apparent at low shear rate. At higher shear rate, the shear stress increases definitively with the increase of kaolin content. On the other hand, the viscosity decreased at a faster rate initially and slows down to monotonous rate as the shear rate increases. Evidently at increasing shear rate, the viscosity tends to become constant as the deviation become smaller which is also known as zero shear rate viscosity region

Rheological properties of Kaolin/PolyetherSulfone(PESf) used in Hollow Fiber Fabrication: effects of content ratio

In the present work, the rheological properties in terms of shear stress and viscosity of Kaolin/Polyether-Sulfone (PESf) of varying ratio were investigated by a rotating rheometer. The shear rate of Kaolin/PESf sample was measured at increasing interval shear rate. By assuming that the fluid behaves like a typical Non-newtonian polymeric liquid, the consistency index, K and flow index, n were able to be determined. Thus, the rheology behaviors of the kaolin/PESf suspension could be investigated at a wider range of shear rate. The shear stress was found to increase with increasing shear rate, with the rate of change quite apparent at low shear rate. At higher shear rate, the shear stress increases definitively with the increase of kaolin content. On the other hand, the viscosity decreased at a faster rate initially and slows down to monotonous rate as the shear rate increases. Evidently at increasing shear rate, the viscosity tends to become constant as the deviation become smaller which is also known as zero shear rate viscosity region