Samiha F. Deriase

Enhancing Biodegradation of Dibenzothiophene by Bacillus sphaericus HN1 Using Factorial Design and Response Surface Optimization of Medium Components

Abstract Based on four levels of full factorial design, a statistical design of experiments is used to investigate two cases of dibenzothiophene biodegradation in batch processes using Bacillus sphaericus HN1, involving as factors, yeast extract and dimethylsulfoxide or magnesium sulfate for first and second cases, respectively. Predictive models have been correlated finding out how significant the effects of these variables (factors) and their interactions are in practice. Also, response surface methodology has been applied to visualize the effect of the studied factors and LINGO software was used to find out the optimum values of the variables for enhancing the process.

Effect of different bioremediation techniques on petroleum biomarkers and asphaltene fraction in oil-polluted sea water

AbstractThe present study has clearly demonstrated that seeding a petroleum hydrocarbon polluted sea water with a halotolerant Pseudomonas aeruginosa Asph2 and corn steep liquor as a cheap and readily available source of nutrients significantly enhances the progress of biodegradation BD of petroleum hydrocarbon pollutants. There was a statistically high significant difference between natural weathering NW and both bioaugmentation BA (p = 2.92e-14) and biostimulation BS (p = 3.56e-13) at 95% confidence interval (α = 0.05). BA significantly improved the efficiency of total petroleum hydrocarbon TPH and the recalcitrant asphaltene degradation by ≈ 23 and 17% compared to BS process (p = 2.0693e-5 and p = 1.4e-3, respectively). The BD of biomarkers; pristane Pr, phytane Ph, and terpanes were very apparent. The BD of C28 tricyclic terpane, C27 13β, 17α- diasterane (20S), and C30 17α, 21β-hopane were higher than that of C35 17α,21β-homohopane. The BD of C27 18α(H)-22,29,30-trisnorneohopane (Ts) was higher than t...

The Optimization of Biodiesel Production from Waste Frying Corn Oil Using Snails Shells as a Catalyst

In this study, calcium oxide as a heterogeneous catalyst for biodiesel production was prepared by a simple calcination process at 800°C for snails shells collected from Egyptian shorelines. D-optimal design of experiments and response surface methodology was applied to analyze the influence of four process variables; methanol:oil (M:O) molar ratio, catalyst concentration (wt%), reaction time (min), and mixing rate (rpm) on biodiesel production through transesterification of waste frying corn oil at 60°C using the prepared biocatalyst. A second order quadratic model was obtained to predict the % biodiesel yield and it adequately described the studied experimental range. Based on the experimental analysis and response surface methodology study, the most suitable operational conditions for this process were: M:O, 6:1 molar ratio; catalyst concentration, 3 wt%; reaction time, 60 min; and mixing rate, 200 rpm. The corresponding predicted % yield of biodiesel was 96.76% and the experimental one was 96%. The activity of the produced green catalyst was comparable to that of chemical CaO and immobilized enzyme Novozym 435.

The Evaluation of Different Bioremediation Processes for Egyptian Oily Sludge Polluted Soil on a Microcosm Level

In this study, bioremediation of an Egyptian oily sludge polluted soil with total petroleum hydrocarbon content of 53,100 mg kg−1 was achieved on a microcosm level at 30°C over a 180-day period. The analysis of variance revealed that soil microcosms biostimulated with corn steep liquor and bioaugmented with Micrococcus lutes RM showed significant removal of total petroleum hydrocarbon relative to natural attenuation microcosms; recording total petroleum hydrocarbon removal of 44 and 54% with p = 0.004 and p = 7.69e-5, respectively. Kinetic study revealed that the degradation processes followed the first-order model. Bioaugmentation microcosms showed also the highest biodegradation efficiencies on different total petroleum hydrocarbon fractions: saturates, aromatics, resins, asphaltene, and the highest soil heterotrophic activity as measured by accumulative evaluation of CO2.

Kinetic evaluation and modeling for batch degradation of 2-hydroxybiphenyl and 2,2′-dihydroxybiphenyl by Corynebacterium variabilis Sh42

abstract This study evaluated the biodegradation kinetics of 2-hydroxybiphenyl (2-HBP) and 2,2′-dihydroxybiphenyl (2,2′-DHBP) with different initial concentrations range S 0 (5–50 mg/L) using suspended cultures of Corynebacterium variabilis Sh42 with fixed initial biomass concentration X 0 (315.8 mg/L) in a series of batch experiments. The cultures followed substrate inhibition kinetics. By fitting specific growth rates μ (h−1) on suitable substrate inhibition models, biokinetic constants that are necessary to understand the kinetics of biodegradation process were evaluated by POLYMATH 6.1 software. Although Haldane and Yano and Koga (2) biokinetic equations for substrate inhibition seem to be the best adequate expressions for specific growth rates on 2-HBP and 2,2′-DHBP, respectively, an evident disagreement was observed between experimental and simulated profiles for bacterial growth X (mg/L) and substrate concentration S (mg/L). Correlation and simulation studies using a new proposed model based on mod...

Waste Eggshells for Production of Biodiesel from Different Types of Waste Cooking Oil as Waste Recycling and a Renewable Energy Process

Based on 3-levels-D-optimal design, involving as factors: methanol:oil, molar ratio; catalyst concentration, wt%; reaction time, min; and type of waste cooking oil, a statistical design of experiments strategy was performed to evaluate and investigate the biodiesel production process from different types of waste cooking oil using CaO prepared from waste eggshells. MATLAB software was employed for experimental design and data analysis. An empirical quadratic regression equation model was obtained describing the interrelationships between dependent and independent variables to maximize the response variable (biodiesel yield). The optimum values of the selected predictor variables were obtained by solving the quadratic model equation using LINGO software. They were found to be: methanol:oil, 9.15:1 molar ratio; catalyst concentration, 7.728 wt%; and reaction time, 75 min, regardless of the type of waste cooking oil used as the feedstock. The qualification and yield of biodiesel were comparable to those prepared using chemical CaO and immobilized standard enzyme Novozym 435.

Evaluation of a bioslurry remediation of petroleum hydrocarbons contaminated sediments using chemical, mathematical and microscopic analysis

This paper concerns the bioremediation of three petroleum hydrocarbon polluted sediment samples collected from the Gulf of Suez, Egypt. The study used a bioslurry system inoculated with Staphylococcus gallinarum NK1, which showed good bioremediation capability regardless of the type of pollutant hydrocarbon and its concentration.

Modeling the relationship between microbial biomass and total viable count for a new bacterial isolate used in biodesulfurization of petroleum and its fractions

ABSTRACT Microbial parameters in a biodesulfurization batch process are often needed to be defined as mass (mg/mL) rather than total viable count (cells/mL) or optical density. This study illustrates mathematical correlations between different techniques used for following up the growth of a new biodesulfurizing bacterial isolate.

The optimization of bio-diesel production from waste frying oil using response surface methodology and the investigation of correlations for changes in basic properties of bio-petro-diesel blends.

Bio-diesel is derived from renewable sources and is steadily gaining attention and significance for use as an alternative or in blends with petro-diesel. In this study, bio-diesel was produced by alkaline-catalyzed transesterification process of waste frying oil at 60°C and 300 rpm. Response surface methodology, based on a central composite design, was employed to statistically evaluate and optimize the conditions for maximum conversion to bio-diesel and to study the significance and interaction of methanol to oil molar ratio, catalyst concentration, and reaction time on bio-diesel yield. A quadratic model equation was obtained for bio-diesel conversion by multiple regression analysis and the validity of the predicted model was confirmed. The optimum combinations for transesterification were determined to be methanol to oil, 9:1; catalyst amount, 0.6%; and reaction time, 1 h. The optimum and actual bio-diesel yields were 99.13 and 98.90%, respectively. The fuel properties of the produced bio-diesel and bio-petro-diesel blends were measured and compared with those of petro-diesel and the American Society for Testing and Materials standards for bio-diesel and bio-petro-diesel blends, and acceptable agreement was observed. Correlations were also established to describe the changes of basic properties of the produced fuel with the volumetric percentage of the bio-diesel for the bio-petro-diesel blends.

The Experimental and Numerical Approach of Catalytic Combustion on Noble Metals Disc Burners of the Turbulent Gaseous Fuel Jet Diffusion Flames

Abstract Catalytic combustion is proposed and developed as an efficient method of promoting stability and oxidation of gaseous fuel with minimum pollutants. The effect of catalytic combustion of gaseous turbulent diffusion flames over catalytic discs containing Pt, Pd, and (Pt + Pd) supported on γ-Al2O3 were experimentally and mathematically studied. These flames have proved to be highly stable over the three catalytic burners and their catalytic enhancement is found to be in the order (Pt + Pd) > Pt > Pd. The axi-symmetric thermal distribution of flames developing over these burners record higher values due to enhancing the fuel oxidizability on the noble metal sites in the reaction zone of flames via improving homogeneous-heterogeneous chemical reactions. Lower values of CO and NO are measured at the axial flames direction in the presence of catalytic burners. A numerical approach has been investigated for the catalytic combustion process on the three noble metals disc burners showing high numerical evaluation of different predicted functions. Stability limits are analyzed following a 1st-degree polynomial. The model of temperatures distribution is described by Gaussian function. For CO distribution, a non-linear four parameters model has been predicted. A differential equation for NO x indicates perfectly the location of the peak values. These models have been strictly confirmed with the experimental data.