Response surface analysis and modeling of n-alkanes removal through bioremediation of weathered crude oil

2011 ◽  
Vol 63 (4) ◽  
pp. 618-626 ◽  
Author(s):  
Leila Mohajeri ◽  
Hamidi Abdul Aziz ◽  
Mohammad Ali Zahed ◽  
Soraya Mohajeri ◽  
Shamsul Rahman Mohamed Kutty ◽  
...  
Keyword(s):  
Crude Oil ◽  
Response Surface ◽  
Natural Attenuation ◽  
Coastal Sediments ◽  
Nitrogen And Phosphorus ◽  
Bacterial Inoculum ◽  
Oil Concentration ◽  
Excessive Nutrients ◽  
Optimized Conditions ◽  
Central Composite

Central composite design (CCD) and response surface methodology (RSM) were employed to optimize four important variables, i.e. amounts of oil, bacterial inoculum, nitrogen and phosphorus, for the removal of selected n-alkanes during bioremediation of weathered crude oil in coastal sediments using laboratory bioreactors over a 60 day experimentation period. The reactors contained 1 kg soil with different oil, microorganisms and nutrients concentrations. The F Value of 26.89 and the probability value (P < 0.0001) demonstrated significance of the regression model. For crude oil concentration of 2, 16 and 30 g per kg sediments and under optimized conditions, n-alkanes removal was 97.38, 93.14 and 90.21% respectively. Natural attenuation removed 30.07, 25.92 and 23.09% n-alkanes from 2, 16 and 30 g oil/kg sediments respectively. Excessive nutrients addition was found to inhibit bioremediation.

Enzyme-assisted Extraction for Optimized Recovery of Phenolic Bioactives from Peganum hermala Leaves Using Response Surface Methodology

2018 ◽  
Vol 17 (4) ◽  
pp. 349-354
Author(s):  
Qadir Rahman ◽  
Anwar Farooq ◽  
Amjad Gilani Mazhar ◽  
Nadeem Yaqoob Muhammad ◽  
Ahmad Mukhtar
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Enzyme Concentration ◽  
Coumaric Acid ◽  
Assisted Extraction ◽  
Pre Treatment ◽  
Optimized Conditions ◽  
Enzyme Complexes ◽  
Hydrolysis Of ◽  
Central Composite

This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuzyme) on recovery of phenolics from Peganum hermala (harmal) leaves, under optimized conditions using response surface methodology. As compared to the other enzyme complexes, the yield (34 g/100g) obtained through Zympex-014-assisted extraction was higher under optimized conditions such as time (75 min), temperature (70°C), pH (6.5) and enzyme concentration (5 g/100 g) using central composite design (CCD). Effectiveness of Zympex-014 towards hydrolysis of P. hermala leaves cell wall was examined by analyzing the control and enzyme-treated leave residues using scanning electron microscope (SEM). GC/MS characterization authenticated the presence of quercetin (1.44), gallic acid (0.23), caffeic acid (0.04), cinnamic acid (0.05), m-coumaric acid (0.23) and p-coumaric acid (0.37 μg/g) as the potent phenolics in Zympex-014 based extract. It can be concluded from the findings of the current work that pre-treatment of P. hermala leaves with Zympex-014 significantly enhanced the recovery of phenolics that supports its potential uses in the nutra-pharamaceutical industry.

Enhanced Alkali Pretreatment of Narrow Leaves Cattail by Response Surface Methodology

2014 ◽  
Vol 875-877 ◽  
pp. 1637-1641
Author(s):  
Arrisa Sopajarn ◽  
Chayanoot Sangwichien
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Residence Time ◽  
Preliminary Test ◽  
Polynomial Equation ◽  
Alkali Concentration ◽  
Pretreatment Condition ◽  
Order Polynomial ◽  
Optimized Conditions ◽  
Central Composite

The purpose of this work is to develop a pretreatment process of lingo-cellulosic ethanol production from narrow leaves cattail (Typha angustifolia) by using alkali catalysis with the response surface methodology (RSM) as a central composite design (CCD). The first step, LiOH, NaOH, and KOH were used as catalytic alkali for preliminary test. Second, the suitable alkali from first step was selected to optimize of pretreatment condition of three independent variables (alkali concentration, temperature, and residence time) that varies at CCD five codes (-2, -1, 0, 1, 2). Sodium hydroxide (NaOH) is the proper alkali because it could increase cellulose more than KOH and nearby LiOH while it is cheapest. RSM result shows the optimized pretreatment condition based on cellulose increased which obtained from this study that is NaOH 5 % w/v at 100 °C and residence time for 120 min. Beside, this condition was analyzed using an ANOVA with a second order polynomial equation after eliminated non-significant terms. At the optimized conditions, cellulose increased, hemicellulose decreased and weight recovery were achieved 77.81%, 80.59, and 41.65%, respectively. Moreover, the model was reasonable to predict the response of strength with less than 5% error.

Response surface optimization of the cultivation conditions and medium components for the production of folate by Streptococcus thermophilus

2010 ◽  
Vol 77 (3) ◽  
pp. 350-356 ◽  
Author(s):  
Ramya Iyer ◽  
Sudhir Kumar Tomar ◽  
Ashish Kumar Singh
Keyword(s):  
Response Surface ◽  
Streptococcus Thermophilus ◽  
Operating Conditions ◽  
Cultivation Conditions ◽  
Optimal Operating ◽  
Medium Components ◽  
Response Surface Optimization ◽  
Modelling Method ◽  
Optimized Conditions ◽  
Central Composite

Optimization of the cultivation conditions and medium components for folate production by the highest folate producing Streptococcus thermophilus strain RD102 was carried out using a 23 central composite design and surface modelling method of response surface methodology. As folate production was observed to be growth-associated, hence the desired responses selected for the optimization were both folate production and growth. The selected factors based on preliminary investigations were incubation period, concentrations of p-amino benzoic acid (PABA) the growth precursor, and lactose as carbon source. The optimum concentrations of PABA and lactose were found to be 300 μm and 3% respectively at 72 h incubation. The optimized conditions resulted in an increase in folate production by 26% compared with control conditions (0% PABA and lactose at 37°C). Using the method of experimental factorial design and response surface analysis, it was possible to determine optimal operating conditions to obtain a higher folate production by Strep. thermophilus. Therefore, this study constitutes a step in developing strategies to modulate the folate level to a higher level.

Optimization of Ferment Condition of ε-Poly-L-Lysine by Response Surface Methodology

2014 ◽  
Vol 934 ◽  
pp. 96-103 ◽  
Author(s):  
Yu Hong Yang ◽  
Hao Wang ◽  
Hong Ling Wang ◽  
Zhuo Wang ◽  
Zong Li Kang
Keyword(s):  
Response Surface ◽  
Polynomial Equation ◽  
Lysine Production ◽  
Culture Volume ◽  
Fermentation Conditions ◽  
Culture Ph ◽  
Surface Method ◽  
Initial Culture ◽  
Optimized Conditions ◽  
Central Composite

Streptomyces albus Y07, a strain which could produce ε-Poly-L-lysine (ε-PL) had been screened in our previous study. The fermentation conditions for ε-Poly-L-lysine production were further optimized through response surface method in this work. A central composite design was adopted to study the effect of culture volume, shaking speed, initial culture pH, as well as inoculation amount on ε-PL production. A quadratic polynomial equation for ε-Poly-L-lysine production was obtained by multiple regression analysis. The equation was as follow: The accuracy and general availability of the polynomial model were proved to be adequate with R2 Pre = 0.8373. The optimized conditions were as follows: culture volumn: 50/500ml, culture pH = 7, inoculation amount: 10% of the total culture volume, shaking speed: 180rpm. Under the optimized conditions, the ε-PL production reached 1.085g / L. And the validity of the predicited model was further confirmed through verification experiments..

Optimization of Preparing Technology of Magnetic Carboxymethylchitosan Microspheres Molecular-Imprinted by 6-ethoxydihydrosanguinarine Using Response Surface Methodology

2015 ◽  
Vol 1090 ◽  
pp. 142-147
Author(s):  
Ming Zhong ◽  
Rui Qing Long
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Adsorption Rate ◽  
Preparation Process ◽  
Optimum Parameters ◽  
Optimized Model ◽  
Oil Water ◽  
Optimized Conditions ◽  
Central Composite ◽  
Water Ratio

In the present study, the response surface methodology (RSM) based on central composite design (CCD) was employed to optimize the preparation process of magnetic carboxymethylchitosan microspheres molecular-imprinted by 6-ethoxydihydrosanguinarine. The optimum parameters were as follows: CMCS concentration,3.24% ;CMCS/EtOSA ratio, 37.79 (g/g) and oil/water ratio, 2.76 (v/v).The adsorption rate from the optimized model was 39.34 (mg/g). Under the optimized conditions, the adsorption rate for the verifying experiments was well matches with the predicted value.

scholarly journals Central Composite Design: a Response Surface Methodology Approach in Biodegradation of Textile Dye Wastewater

2021 ◽  
Vol 43 (6) ◽  
pp. 461-475
Author(s):  
Nur Hanis Mohamad Hanapi ◽  
Sharifah Hanis Yasmin Sayid Abdullah ◽  
Azimah Ismail ◽  
Hafizan Juahir
Keyword(s):  
Response Surface Methodology ◽  
Chemical Oxygen Demand ◽  
Central Composite Design ◽  
Response Surface ◽  
Process Parameters ◽  
Oxygen Demand ◽  
Textile Dye ◽  
Initial Concentration ◽  
Bacterial Inoculum ◽  
Central Composite

Objectives : This study evaluated and identified the removal of colors and chemocal oxygen demands from thextile dye effluents by Bacillus cereus isolated from the local textile wastewater treatment plant.Methods : Central composite design (CCD) from response surface methodology (RSM) was applied in order to achieve the optimized treatment process condition for the textile dyes wastewater degradation. Two-level of three process parameters with six center points resulted a total of twenty runs of experiments were performed. Bacterial inoculum (-1,+1) (%, v/v), agitation (-1, +1) (rpm), and pH (-1, +1) were tested.Results and Discussion : During the ten days of biodegradation process, highest decolourization achieved was 88.67% with low pH and agitation; and medium level of initial concentration of bacterial inoculum. Highest chemical oxygen demand (COD) removal was achieved with 99.20% from high pH (pH 10), low agitation (100 rpm) and high initial concentration of bacterial inoculum (15%, v/v).Conclusions : The biological treatments was able to remove colour and chemical oxygen demand with application of CCD, giving the optimum settings of the three process parameters studied.

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