Nor Azimah Mohd Zain

Synergistic effect of optimizing light-emitting diode illumination quality and intensity to manipulate composition of fatty acid methyl esters from Nannochloropsis sp.

In the study, the relationship between the quality and intensity of LED illumination with FAMEs produced were investigated. Nannochloropsis sp. was cultivated for 14 days under different intensities of 100, 150 and 200 μmol photons m(-2) s(-1) of red, blue and mixed red blue LED. The findings revealed that suitable combination of LED wavelengths and intensity; (red LED: 150, blue: 100 and mixed red blue: 200 μmol photons m(-2) s(-1)) produced maximum biomass growth and lipid content. It was observed that the quality and intensity of LED significantly influenced the composition of FAMEs. FAMEs produced under blue LED has high degree of unsaturation (DU) and low cetane number while those under red LED has low DU but higher CN. The combination of red blue LED has produced FAMEs with high ignition and lubricating property and also good oxidation stability indicated by the DU and CN values which lies midway between the red and blue.

Discoloration of aqueous textile dyes solution by Phanerochaete chrysosporium immobilized in modified PVA matrix

AbstractThis study investigates the performance of immobilized Phanerochaete chrysosporium in modified PVA matrix in removing a mixture of textile dyes consisting of Yellow FG, Red 3BS, Orange 3R, Blue RSP, Black B, and remazol turquoise blue from aqueous solution. The effects of agitation and temperature were thoroughly investigated in determining the optimum operating condition of dye discoloration using central composite design. Optimum condition was determined as 100 rpm and 35°C. Evidently, adsorption only plays a minor role in removing these dyes as it contributes to about 8% of color removal. The rest of color removal could be attributed to fungal enzymatic biodegradation, particularly the highly regarded manganese peroxidase. Manganese peroxidase assay revealed that a maximum enzyme activity of 174 U/l was achieved in the third cycle of repeated use. The reusability test also revealed that the immobilized fungus could be used for up to six cycles with a peak of 82% of discoloration, where discolor...