Investigation of equilibrium and kinetics of Cr(VI) adsorption by dried Bacillus cereus using response surface methodology

2015 ◽  
Vol 73 (3) ◽  
pp. 617-627 ◽  
Author(s):  
Kai Yang ◽  
Jing Zhang ◽  
Tao Yang ◽  
Hongyu Wang
Keyword(s):  
Response Surface Methodology ◽  
Bacillus Cereus ◽  
Response Surface ◽  
Polynomial Equation ◽  
Surface Chemical ◽  
Biosorption Process ◽  
Key Factor ◽  
Equilibrium And Kinetics ◽  
Kinetics Of ◽  
Central Composite

In this study, response surface methodology (RSM) based on three-variable-five-level central composite rotatable design was used to analyze the effects of combined and individual operating parameters (biomass dose, initial concentration of Cr(VI) and pH) on the Cr(VI) adsorption capacity of dried Bacillus cereus. A quadratic polynomial equation was obtained to predict the adsorbed Cr(VI) amount. Analysis of variance showed that the effect of biomass dose was the key factor in the removal of Cr(VI). The maximum adsorbed Cr(VI) amount (30.93 mg g−1) was found at 165.30 mg L−1, 2.96, and 3.01 g L−1 for initial Cr(VI) concentration, pH, and biosorbent dosage, respectively. The surface chemical functional groups and microstructure of unloaded and Cr(VI)-loaded dried Bacillus cereus were identified by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM), respectively. Besides, the results gained from these studies indicated that Langmuir isotherm and the second-order rate expression were suitable for the removal of Cr(VI) from wastewater. The results revealed RSM was an effective method for optimizing biosorption process, and dried Bacillus cereus had a remarkable performance on the removal of Cr(VI) from wastewater.

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.

scholarly journals Optimization of Oxidative Leaching for Vanadium Extraction from Low-Grade Stone Coal Using Response Surface Methodology

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1534
Author(s):  
Zulv Huang ◽  
Tao Chen ◽  
Yang Zhou ◽  
Wenbin Xu ◽  
Hanzhi Lin ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Low Grade ◽  
Stone Coal ◽  
H2so4 Concentration ◽  
Before And After ◽  
Shrinking Core ◽  
Oxidative Leaching ◽  
Kinetics Of ◽  
Central Composite

The feasibility and kinetics of vanadium (V) recovery from oxidative leaching of low-grade stone coal using MnO2 were investigated. Oxidative leaching processes (OLPs) were designed using response surface methodology (RSM) based on the central composite design (CCD) model. The results show that the order of factors that influence OLPs is leaching temperature > H2SO4 concentration > leaching time > MnO2 dosage. The interaction between leaching temperature and H2SO4 concentration on the OLP is the most significant. Vanadium leaching efficiency was 89.3% using 31% H2SO4 and 3% MnO2 at 90 °C for 7.9 h. The kinetics of V leaching from stone coal show that the leaching rate is controlled by chemical reaction through a layer according to the shrinking core model and the activation energy is 55.62 kJ/mol. A comparison of the SEM-EDS results of minerals before and after leaching confirms that the muscovite structure was significantly destroyed and V and aluminum (Al) were effectively dissolved during the OLP.

scholarly journals Optimization of Conversion of High Free Fatty Acid Jatropha curcas Oil to Biodiesel Using Response Surface Methodology

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Prerna Goyal ◽  
M. P. Sharma ◽  
Siddharth Jain
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Jatropha Curcas ◽  
Methyl Esters ◽  
Polynomial Equation ◽  
Molar Ratio ◽  
Optimum Level ◽  
Acid Catalyzed ◽  
Central Composite ◽  
Good Agreement

A five-level-four-factor central composite design (CCD) with 54 assays was employed to study the effect of catalyst concentration (NaOH), reaction temperature, reaction time, and methanol/oil molar ratio on the methyl esters yield from Jatropha curcas oil (JCO) during its transesterification. Using response surface methodology (RSM), a quadratic polynomial equation was obtained for Jatropha curcas biodiesel (JCB) yield by regression analysis. Verification experiments confirmed the validity of the predicted model. The high free fatty acids (FFAs) (14.6%) of JCO could be reduced to 0.34% by acid-catalyzed esterification and a JCB yield of 98.3% was obtained with methanol/oil ratio (11 : 1) using NaOH as catalyst (1% w/w) in 110 min time at 55°C temperature. The predicted value of JCB yield is found to be in good agreement with the experimental value at the optimum level of input parameters. The properties of the biodiesel, thus, produced conform to the ASTM and IS specifications, making it an ideal alternative fuel for diesel engines. The model can be effectively used in oil industry to maximize the biodiesel yield from given oil.

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.

Optimisation of the Oil Extraction from Nigella sativa Seeds Using Response Surface Methodology

2017 ◽  
Vol 68 (2) ◽  
pp. 331-336
Author(s):  
Gabriela Isopencu ◽  
Mirela Marfa ◽  
Iuliana Jipa ◽  
Marta Stroescu ◽  
Anicuta Stoica Guzun ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Nigella Sativa ◽  
Polynomial Equation ◽  
Herbaceous Plant ◽  
Box Behnken Design ◽  
Pareto Analysis ◽  
Black Cumin ◽  
Mediterranean Countries ◽  
Experimental Values

Nigella sativa, also known as black cumin, an annual herbaceous plant growing especially in Mediterranean countries, has recently gained considerable interest not only for its use as spice and condiment but also for its healthy properties of the fixed and essential oil and its potential as a biofuel. Nigella sativa seeds fixed oil, due to its high content in linoleic acid followed by oleic and palmitic acid, could be beneficial to human health. The objective of this study is to determine the optimum conditions for the solvent extraction of Nigella sativa seeds fixed oil using a three-level, three-factor Box-Behnken design (BBD) under response surface methodology (RSM). The obtained experimental data, fitted by a second-order polynomial equation were analysed by Pareto analysis of variance (ANOVA). From a total of 10 coefficients of the statistical model only 5 are important. The obtained experimental values agreed with the predicted ones.

Response Surface Methodology towards Optimization of Calotropis Procera Essential oil Extraction by using Supercritical CO2.

2019 ◽  
Vol 09 ◽  
Author(s):  
Hossein Zaeri ◽  
Bahareh Kamyab Moghadas ◽  
Bijan Honarvar ◽  
Ali Shokuhi Rad
Keyword(s):  
Response Surface Methodology ◽  
Essential Oil ◽  
Response Surface ◽  
Extraction Time ◽  
Calotropis Procera ◽  
Retrieval Rate ◽  
The Family ◽  
Effects Of Temperature ◽  
Carbon Dioxide Co2 ◽  
Central Composite

: In this research, the extraction of essential oil from Calotropis Procera with the family name of Asclepiadaceae, by supercritical carbon dioxide (CO2) solvent has been investigated in detail, and the yield and chemical profile of the extracts achieved by this method were compared with those resulted by the conventional Hydro distillation method. To optimize the process parameters of CO2 supercritical extraction (SCE) of the Calotropis Procera, the Response Surface Methodology (RSM) with central composite design (CCD) was employed. The effects of temperature, pressure, and extraction time on the oil yield are considered for investigation. Results showed that the data were sufficiently fitted into the second-order polynomial model. The extraction conditions, including pressure, temperature, and extraction time, were studied between 150-200 bar, 40-50 ºC, and 50-100 min, respectively. The optimal conditions are achieved as the temperature of 47.19ºC, the pressure of 172.2 bar, and time of 86 minutes with the retrieval rate of 31.39%.

scholarly journals Optimizing of Microalgae Scenedesmus sp. Biomass Production in Wet Market Wastewater Using Response Surface Methodology

2021 ◽  
Vol 13 (4) ◽  
pp. 2216
Author(s):  
Najeeha Mohd Apandi ◽  
Mimi Suliza Muhamad ◽  
Radin Maya Saphira Radin Mohamed ◽  
Norshuhaila Mohamed Sunar ◽  
Adel Al-Gheethi ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Biomass Yield ◽  
Biomass Productivity ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Aeration Rate ◽  
Composition Analysis ◽  
Wet Market ◽  
Central Composite

The present study aimed to optimize the production of Scenedesmus sp. biomass during the phycoremediation process. The biomass productivity was optimized using face centred central composite design (FCCCD) in response surface methodology (RSM) as a function of two independent variables that included wet market wastewater concentrations (A) with a range of 10% to 75% and aeration rate (B) with a range of 0.02 to 4.0 L/min. The results revealed that the highest biomass productivity (73 mg/L/d) and maximum growth rate (1.19 day−1) was achieved with the 64.26% of (A) and 3.08 L/min of (B). The GC-MS composition analysis of the biomass yield extract revealed that the major compounds are hexadecane (25%), glaucine (16.2%), and phytol (8.33%). The presence of these compounds suggests that WMW has the potential to be used as a production medium for Scenedesmus sp. Biomass, which has several applications in the pharmaceutical and chemical industry.

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