Mohd Azmuddin Abdullah
Universiti Teknologi Petronas
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Featured researches published by Mohd Azmuddin Abdullah.
Biotechnology and Bioprocess Engineering | 2006
Rozita Omar; Mohd Azmuddin Abdullah; M. A. Hasan; M. Rosfarizan; M. Marziah
In this study, we have conducted kinetics and modelling studies ofCentella asiatica cell growth and substrate uptake, in an attempt to evaluate cell growth for a better understanding and control of the process. In our bioreactor cultivation experiment, we observed a growth rate of 0.18/day, a value only 20% higher than was seen in the shake flask cultivation trial. However, the observed maximum cell dry weight in the shake flask, 10.5 g/L, was 14% higher than was achieved in the bioreactor. Ninety seven percentage confidence was achieved via the fitting of three unstructured growth models; the Monod, Logistic, and Gompertz equations, to the cell growth data. The Monod equation adequately described cell growth in both cultures. The specific growth rate, however, was not effectively predicted with the Logistic and Gompertz equations, which resulted in deviations of up to 73 and 393%, respectively. These deviations in the Logistic and Gompertz models may be attributable to the fact that these models were developed for substrate-independent growth and fungi growth, respectively.
Biotechnology and Bioprocess Engineering | 2005
Rozita Omar; Mohd Azmuddin Abdullah; M. A. Hasan; M. Marziah; M.K. Siti Mazlina
The effects of macronutrients (NO3−, NH4+ and PO43−) on cell growth and triterpenoids production inCentella asiatica cell suspension cultures were analyzed using the Box-Behnken response surface model experimental design. In screening and optimization experiments, PO43− as a single factor significantly influenced cell growth where increasing the phosphate level from 0.1 to 2.4 or 2.6 mM, elevated cell growth from 3.9 to 14–16 g/L. The optimum values predicted from the response surface model are 5.05 mM NH4+, 15.0 mM NO3− and 2.6 mM PO43−, yielding 16.0 g/L cell dry weight with 99% fitness to the experimental data. While the NH4+-NO3− interaction influenced cell growth positively in the optimization experiment, NH4+ and NO3− as single factors; and interactions of NO3−-PO43−, NH4+-PO43− and NH4+-NO3− were all negative in the screening experiment. Cell growth and the final pH level were positively affected by PO43−, but negatively affected by NH4+ and NH4+-PO43− interactions. The different effects of factors and their interactions on cell growth and final pH are influenced by a broad or narrow range of macronutrient concentrations. The productions of triterpenoids however were lower than 4 mg/g cell dry weight.
Advanced Materials Research | 2014
Ashfaq Ahmad; Syed Muhammad Usman Shah; Azizul Buang; Mohd Fariduddin Othman; Mohd Azmuddin Abdullah
This study investigated co-cultivation of Tetraselmis suecica microalgae with Oil Palm empty fruit bunch (OPEFB) for anaerobic biomethane production and Palm oil mill effluent (POME) treatment. The highest specific biogas production (0.1162 m3 kg-1 COD day-1) and biomethane yield (3900.8 mL CH4 L-1 POME day-1) was achieved with microalgae at 2 mL mL-1 POME, and OPEFB at 0.12 g mL-1 POME. Without co-digestion of microalgae, higher specific biogas production (0.1269 m3 kg-1 COD day-1) but lower biomethane yield (3641.8 mL CH4 L-1 POME day-1) were observed. Second order polynomial model fits the data well with less than 5% error. Higher removal efficiency (62-95%) of COD, BOD, TOC and TN were achieved by aerobic and anaerobic treatment of POME with microalgae than without microalgal treatment after 3 and 7 days of hydraulic retention time (HRT).
International Journal of Green Energy | 2016
Syed Muhammad Usman Shah; Ashfaq Ahmad; Mohd Fariduddin Othman; Mohd Azmuddin Abdullah
ABSTRACT In this study, palm oil mill effluent (POME) was used as an alternative medium for algal biomass and lipid production. The influence of different concentrations of filtered and centrifuged POME in sea water (1, 5, 10 and 15%) on microalgal cell growth and lipid yield were investigated. Both Nannochloropsis oculata and Tetraselmis suecica had enhanced cell growth and lipid accumulation at 10% POME with maximum specific growth rate (0.21 d–1 and 0.20 d–1) and lipid content (39.1 ± 0.73% and 27.0 ± 0.61%), respectively, after 16 days of flask cultivation. The total Saturated Fatty Acid (SFA) (59.24%, 68.74%); Monounsaturated Fatty Acid (MUFA) (15.14%, 12.26%); and Polyunsaturated Fatty Acid (PUFA) (9.07%, 8.88%) were obtained for N. oculata and T. suecica, respectively, at 10% POME. Algal cultivation with POME media also enhanced the removal of Chemical Oxygen Demand (COD) (93.6–95%), Biological Oxygen Demand (BOD) (96–97%), Total Organic Compound (TOC) (71–75%), Total Nitrogen (TN) (78.8–90.8%) and oil and grease (92–94.9%) from POME.
Biotechnology and Bioprocess Engineering | 2016
Mohd Azmuddin Abdullah; Ashfaq Ahmad; Syed Muhammad Usman Shah; Sanaa Mahmoud Metwally Shanab; Hamdy Elsayed Ahmed Ali; Mervat Aly Mohamed Abo-State; Mohd Fariduddin Othman
Increased demand for energy worldwide has resulted in increasing interest in alternative renewable sources of biofuels. Demand for improved systems of bioenergy generation, environmental remediation, and coproduction of high value bioactive compounds has led to the potential use of algae in biomass utilization. In Malaysia, palm oil industries generate high amount of solid wastes. Palm Oil Mill Effluent (POME) is estimated to be three times of the amount of crude palm oil produced. POME is a heavily polluting wastewater due to its high chemical oxygen demand (COD), high biochemical oxygen demand (BOD), and high contents of minerals such as nitrogen and phosphorus that can cause severe pollution to the environment and water resources. A combination of wastewater treatment and renewable bioenergy co-generation with recovery of high-value biochemicals would benefit the palm oil industry.
Desalination and Water Treatment | 2015
Mohd Azmuddin Abdullah; M. Afzaal; Z. Ismail; Ashfaq Ahmad; M.S. Nazir; A.H. Bhat
AbstractThe performance of raw Ceiba pentandra (L.) Gaertn (raw kapok fibers (RKF)) for oil sorption and palm oil mill effluent (POME) treatment was compared with structurally modified kapok (NaOH-treated (SKF) and surface-modified kapok fiber (SMKF)) and bentonite clay. Based on FTIR, kapok wax functional group at 1726/cm was not detected in SKF rendering higher hydrophilicity. The reduction in peak intensity at 473 and 523/cm upon HCl treatment of bentonite, suggests the cleavage of Si–O–Al bond layer and Si–O–Mg (Fe) bonds. For filtration under gravity at 0.08 g/cm3, SKF showed high POME sorption of 82 g/g, but lower diesel sorption of 23 g/g. With HCl-treated bentonite, POME sorption at 69 g/g was only slightly higher than diesel sorption of 60 g/g. However, RKF and raw bentonite achieved higher removal efficiency of biological oxygen demand, chemical oxygen demand (COD), total organic carbon, and total nitrogen at 74–98% and 72–94%, respectively, than with SKF at 66–80%, and HCl-treated bentonite at ...
The Scientific World Journal | 2014
Huma Ajab; Asim Yaqub; Salman Akbar Malik; Muhammad Junaid; Sadia Yasmeen; Mohd Azmuddin Abdullah
In this study, concentrations of Cd, Ni, Pb, and Cr were determined in tobacco, tobacco smoke-condensate, and cigarette ash for selected brands used in Pakistan. Smoking apparatus was designed for metal extraction from cigarette smoke. Samples were digested through microwave digester and then analyzed by flame atomic absorption spectrophotometer (FAAS). Higher concentration of Ni was detected in imported brands than the counterparts in the local brands. Pb levels were however higher in local brands while significant concentration of Cd was observed in both brands. For Cr, the level in tobacco of local brands was higher than their emitted smoke, whereas imported brands showed higher level in smoke than in tobacco. The cigarette ash retained 65 to 75% of the metal and about 25 to 30% went into the body. While this study revealed the serious requirement to standardize the manufacturing of tobacco products, more importantly is the urgent need for stronger enforcements to put in place to alert the general population about the hazardous effects of cigarettes and the health risks associated with these toxic metals.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | 2014
Eny Kusrini; Rita Arbianti; Nofrijon Sofyan; Mohd Azmuddin Abdullah; Fika Andriani
In the presence of hydroxyl and amine groups, chitosan is highly reactive; therefore, it could be used as a carrier in drug delivery. For this study, chitosan-Sm complexes with different concentrations of samarium from 2.5 to 25 wt.% have been successfully synthesized by the impregnation method. Chitosan combined with Sm3+ ions produced a drug carrier material with fluorescence properties; thus, it could also be used as an indicator of drug release with ibuprofen (IBU) as a model drug. We evaluated the spectroscopic and interaction properties of chitosan and Sm3+ ions, the interaction of chitosan-Sm matrices with IBU as a model drug, and the effect of Sm3+ ions addition on the chitosan ability to adsorb the drug. The result showed that the hypersensitive fluorescence intensity of chitosan-Sm (2.5 wt.%) is higher than the others, even though the adsorption efficiency of chitosan-Sm 2.5wt.% is lower (29.75%) than that of chitosan-Sm 25 wt.% (33.04%). Chitosan-Sm 25 wt.% showed the highest efficiency of adsorption of ibuprofen (33.04%). In the release process of ibuprofen from the chitosan-Sm-IBU matrix, the intensity of orange fluorescent properties in the hypersensitive peak of 4G5/2→6H7/2 transition at 590 nm was observed. Fluorescent intensity increased with the cumulative amount of IBU released; therefore, the release of IBU from the Sm-modified chitosan complex can be monitored by the changes in fluorescent intensity.
Applied Mechanics and Materials | 2014
Hamdy Elsayed Ahmed Ali; Sanaa Mahmoud Metwally Shanab; Mervat Aly Mohamed Abo-State; Emad A. Shalaby; Usama Eldmerdash; Mohd Azmuddin Abdullah
Ten different microalgal species were screened for their antioxidant activity using 2,2 ́-diphenyl-1-picrylhydrazyl (DPPH) scavenging assay, both total phenolic and carotenoid contents were determined. The ethanolic extract of Oscillatoria sp. showed the highest antioxidant activity (69.1 %), while the green Chlorella sp. showed higher phenolic content (39.1 mg GAE g-1 dry wt.) and Scenedesmus obliquus recorded higher carotenoid content (3.73 mg L-1), than cyanobacterial species Microalgal biomass plays a great role as a potential source of natural antioxidants, not only due to the carotenoids but also the phenolic compounds.
Applied Mechanics and Materials | 2014
Muhammad Afzaal; Balasubramanian Periyasamy; Mohd Azmuddin Abdullah
Packed bed column studies were carried out to evaluate the performance of natural Ceiba pentandra (L). Gaertn. (kapok) for the heavy metal removal from Palm Oil Mill Effluent (POME) under varying flow rate (5-10 ml/min) and packing density (0.04-0.08 g/cm3). A multilevel factorial design based on Packing density and flow rate of the influent was developed. Maximum metal reductions for Fe, Mn and Zn were 2.06 ppm, 0.081 ppm, and 0.064 ppm respectively obtained at 0.08 g/cm3 packing density and 5 ml/min flow rate. The results suggest the suitability of raw kapok fiber for low-cost removal of heavy metals.