scholarly journals Optimization of Chromium Removal by the Indigenous Bacterium Bacillus spp. REP02 Using the Response Surface Methodology

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
C. K. Venil ◽  
V. Mohan ◽  
P. Lakshmanaperumalsamy ◽  
M. B. Yerima

An indigenous bacterium, Bacillus REP02, was isolated from locally sourced chromium electroplating industrial effluents. Response surface methodology was employed to optimize the five critical medium parameters responsible for higher % Cr2+ removal by the bacterium Bacillus REP02. A three-level Box-Behnken factorial design was used to optimize K2HPO4, yeast extract, MgSO4, NH4NO3, and dextrose for Cr2+ removal. A coefficient of determination (R2) value (0.93), model F-value (3.92) and its low P-value (F<0.0008) along with lower value of coefficient of variation (5.39) indicated the fitness of response surface quadratic model during the present study. At optimum parameters of K2HPO4 (0.6 g L−1), yeast extract (5.5 g L−1), MgSO4 (0.04 g L−1), NH4NO3 (0.20 g L−1), and dextrose (12.50 g L−1), the model predicted 98.86% Cr2+ removal, and experimentally, 99.08% Cr2+ removal was found.

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Mojdeh Dinarvand ◽  
Malahat Rezaee ◽  
Malihe Masomian ◽  
Seyed Davoud Jazayeri ◽  
Mohsen Zareian ◽  
...  

The study is to identify the extraction of intracellular inulinase (exo- and endoinulinase) and invertase as well as optimization medium composition for maximum productions of intra- and extracellular enzymes fromAspergillus nigerATCC 20611. From two different methods for extraction of intracellular enzymes, ultrasonic method was found more effective. Response surface methodology (RSM) with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. The effect of five main reaction parameters including sucrose, yeast extract, NaNO3, Zn+2, and Triton X-100 on the production of enzymes was analyzed. A modified quadratic model was fitted to the data with a coefficient of determination (R2) more than 0.90 for all responses. The intra-extracellular inulinase and invertase productions increased in the range from 16 to 8.4 times in the optimized medium (10% (w/v) sucrose, 2.5% (w/v) yeast extract, 2% (w/v) NaNO3, 1.5 mM (v/v) Zn+2, and 1% (v/v) Triton X-100) by RSM and from around 1.2 to 1.3 times greater than in the medium optimized by one-factor-at-a-time, respectively. The results of bioprocesses optimization can be useful in the scale-up fermentation and food industry.


2021 ◽  
Author(s):  
M.A. Olivares-Ramírez ◽  
Leticia López-Zamora ◽  
M.J. Peña-Juárez ◽  
E.J. Gutiérrez-Castañeda ◽  
J.A. Gonzalez-Calderon

Abstract The present work shows the implementation of the Response Surface Methodology (RSM), fed by an experimental Central Composite Design (CCD) to find the conditions that allow maximizing the inhibition of the microorganism Staphylococcus aureus with nanoparticles of TiO2 silanized with 3-Aminopropyltriethoxysilane (APTES) and doped with Ag. In addition, Poly(lactic) acid composites were prepared with these Ag/TiO2 nanoparticles with the aim to confer their antimicrobial effect. The independent variables considered were pH, AgNO3/TiO2 ratio (% w/w), and TiO2 nanoparticles concentration (g/250 mL), and as the variable of response, the length of the diameter of the halo or zone of inhibition presented by the microorganism (mm). Statistical analysis found that maximization of S. aureus inhibition occurs at intermediate levels with a value of 10 for pH and 5 g of TiO2 solids, while for the concentration of AgNO3 high levels are required, greater than 10% w/w. Likewise, the statistical significance was determined using the Student's t-test and the p-value; it was found that the significant effect corresponds to the concentration of AgNO3, so a second experimental CCD design equirradial with two factors was considered, estimating AgNO3 concentration and TiO2 amount, the pH at constant 10 value. The second experimental design indicated that maximization in S. aureus inhibition occurs at an AgNO3 concentration between 20-25% w/w with high amounts of TiO2 solids (7-8 g), with a resulting zone of inhibition between 26-28 mm. The quadratic model obtained, which represents the relationship between the length of the zone of inhibition with the variables considered, shows an adjustment of experimental data with a coefficient of determination (R2) of 0.82.


2017 ◽  
Vol 76 (2) ◽  
pp. 323-336 ◽  
Author(s):  
Muhammad Z. Ahamd ◽  
S. Ehtisham-ul-Haque ◽  
Numrah Nisar ◽  
Khizar Qureshi ◽  
Abdul Ghaffar ◽  
...  

The present study was conducted to degrade and detoxify 2-chlorophenol (2-CP) under UV irradiation in the presence of titanium dioxide (TiO2) and hydrogen peroxide (H2O2). The treatment efficiency was evaluated on the basis of degradation and cytotoxicity reduction as well as biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total organic carbon (TOC) removal. The process variables such as TiO2, pH, UV irradiation time and H2O2 were optimized. Central composite design in combination with response surface methodology was employed to optimize the process variables. A quadratic model was proposed to predict the treatment efficiency and analysis of variance was used to determine the significance of the variables. The correlation between the experimental and predicted degradation was confirmed by the F and P values (&lt;0.05). The coefficient of determination (R2 = 0.99) were high enough to support the validity of developed model. At optimized conditions, up to 92% degradation of 2-CP was achieved with 3.5 × 10−4 s−1 rate constant. Significant reductions in BOD, COD and TOC values were also achieved. Cytotoxicity was evaluated using bioassays and it was observed that UV/TiO2/H2O2 reduced the cytotoxicity considerably. It is concluded that UV/TiO2/H2O2 could possibly be used to detoxify 2-CP in industrial wastewater.


Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 588
Author(s):  
Poh Gaik Law ◽  
Noor Haida Sebran ◽  
Ashraf Zin Zawawi ◽  
Azlan Shah Hussain

Statistical-based study using response surface methodology (RSM) was conducted to study the effects of process parameters towards biomass hydrogenation. Using Malaysian oil palm empty fruit bunches (EFB) fibres as feedstock, the central composite design (CCD) technique was employed and 18 runs were generated by CCD when four parameters (mass ratio of binary catalyst, hydrogen pressure, temperature and mass ratio of catalyst to feedstock) were varied with two center points to determine the effects of process parameters and eventually to get optimum ethylene glycol (EG) yield. RSM with quadratic function was generated for biomass hydrogenation, indicating all factors except temperature, were important in determining EG yield. Analysis of variance (ANOVA) showed a high coefficient of determination (R2) value of >0.98, ensuring a satisfactory prediction of the quadratic model with experimental data. The quadratic model suggested the optimum EG yield should be >25 wt.% and the EG yield results were successfully reproduced in the laboratory.


2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Samar A. El-Mekkawi ◽  
Rehab A. Abdelghaffar ◽  
Fatma Abdelghaffar ◽  
S. A. Abo El-Enin

Abstract Background Conservation of the ecosystem is a prime concern of human communities. Industrial development should adopt this concern. Unfortunately, various related activities release lots of noxious materials concurrently with significant leakage of renewable resources. This work presents a new biosorbent activated de-oiled microalgae, Chlorella vulgaris, (AC) for biosorption of Acid Red 1 (AR1) from aqueous solution simulated to textile dyeing effluent. The biosorption characteristics of AC were explored as a function of the process parameters, namely pH, time, and initial dye concentration using response surface methodology (RSM). Results Optimization is carried out using the desirability approach of the process parameters for maximum dye removal%. The ANOVA analysis of the predicted quadratic model elucidated significant model terms with a regression coefficient value of 0.97, F value of 109.66, and adequate precision of 34.32 that emphasizes the applicability of the model to navigate the design space. The optimization depends on the priority of minimizing the time of the process to save energy and treating high concentrated effluent resulted in removal % up to 83.5%. The chemical structure and surface morphology of AC, and the dye-loaded biomass (AB) were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and transmission electron microscope (TEM). The activation process transforms the biomass surface into a regular and small homogeneous size that increases the surface area and ultimately enhances its adsorption capacity Conclusion The optimization of the process parameters simultaneously using RSM performs a high-accurate model which describes the relationship between the parameters and the response through minimum number of experiments. This study performed a step towards an integrated sustainable solution applicable for treating industrial effluents through a zero-waste process. Using the overloaded biomass is going into further studies as micronutrients for agricultural soil.


2015 ◽  
Vol 7 (1) ◽  
pp. 203-210
Author(s):  
R. Poorniammal ◽  
S. Gunasekaran ◽  
R. Murugesan

In present study, Thermomyces sp. were able to produce high yield of yellow pigments screened. Pigment production by Thermomyces sp was optimized by employing factorial design and response surface techniques in submerged fermentation. The variables evaluated were the concentrations of, sucrose, yeast extract, ammonium sulphate, magnesium sulphate and dipotassium hydrogen phosphate having as response pigment production. One factor at-a-time method was employed for the optimization of media components. Response surface methodology (RSM) optimized these nutrient parameters for maximum yellow pigment production (1387 OD units), which resulted at 35.5 g/L sucrose 5.5 g/L yeast extract, 2.5 g/L NH4SO4, 0.3 g/L MgSO4 and 1.0 g/L K2HPO4 in the medium. Response surface methodology (RSM) was further used to determine the optimum values of process variables for maximum yellow pigment production. The fit of the quadratic model was found to be significant. A significant increase in yellow pigment production was achieved using RSM.


2017 ◽  
Vol 69 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Nor Syahirah Mohamad ◽  
Salmiah Kasolang

Purpose An optimized model is often deployed to reduce trial and error in experimental approach and obtain the multi-variant correlation. In this study, response surface methodology (RSM), namely, Box–Behnken design (BBD) approach, has been used to optimize the characterization of lubricant with additives. BBD is based on multivariate analysis whereby the effects of different parameters are considered simultaneously. It is a non-linear system which is more representative of the actual phenomenon. This study aims to investigate the effect of three independent variables, namely, speed, load and concentration of TiO2, on the coefficient of friction (CoF). Design/methodology/approach RSM was applied to get the multiplicity of the self-determining input variables and construct mathematical models. Mathematical models were established to predict the CoF and to conduct a statistical analysis of the independent variables’ interactions on response surface using Minitab 16.0 statistical software. Three parameters were regulated: speed (X1), load (X2) and concentration of TiO2 (X3). The output measured was the CoF. Findings The result obtained from BBD has shown that the most influential parameter was speed, followed by concentration of TiO2 nanoparticles and then normal load. Analysis of variance indicated that the proposed experiment from the quadratic model has successfully interpreted the experimental data with a coefficient of determination R2 = 0.9931. From the contour plot of BBD, the optimization zone for interacting variables has been obtained. The zone indicates two regions of lower friction values (<0.04): concentration between 0.5 to 1.0 Wt.% for a speed range of 1,000 to 2,000 rpm, and load between 17 to 20 kg for a speed in the range of 1,200 to 1,900 rpm. The optimized condition shows that the minimum value of CoF (0.0191) is at speed of 1,782 rpm, load of 20 kg and TiO2 concentration of 1.0 Wt.%. Originality/value In general, it has been shown that RSM is an effective and powerful tool in experimental optimization of multi-variants.


2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


2021 ◽  
Vol 11 (4) ◽  
pp. 1739
Author(s):  
Muhammad Ajaz Ahmed ◽  
Jae Hoon Lee ◽  
Joon Weon Choi

A synergistic combination of dioxane, acetic acid, and HCl was investigated for lignin extraction from pine wood biomass. After initial screening of reagent combination, response surface methodology (RSM) was used to optimize the lignin yield with respect to the variables of time 24–72 h, solids loading 5–15%, and catalyst dose 5–15 mL. A quadratic model predicted 8.33% of the lignin yield, and it was further confirmed experimentally and through the analysis of variance (ANOVA). Lignin at optimum combination exhibited features in terms of derivatization followed by reductive cleavage (DFRC) with a value of (305 µmol/gm), average molecular weights of 4358 and polydispersity of 1.65, and 2D heteronuclear single quantum coherence nuclear magnetic resonance spectrum (2D-HSQC NMR) analysis showing relative β-O-4 linkages (37.80%). From here it can be suggested that this fractionation can be one option for high quality lignin extraction from lignocellulosic biomass.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3150
Author(s):  
Mengwei Xu ◽  
Chao Huang ◽  
Jing Lu ◽  
Zihan Wu ◽  
Xianxin Zhu ◽  
...  

Magnetic MXene composite Fe3O4@Ti3C2 was successfully prepared and employed as 17α-ethinylestradiol (EE2) adsorbent from water solution. The response surface methodology was employed to investigate the interactive effects of adsorption parameters (adsorption time, pH of the solution, initial concentration, and the adsorbent dose) and optimize these parameters for obtaining maximum adsorption efficiency of EE2. The significance of independent variables and their interactions were tested by the analysis of variance (ANOVA) and t-test statistics. Optimization of the process variables for maximum adsorption of EE2 by Fe3O4@Ti3C2 was performed using the quadratic model. The model predicted maximum adsorption of 97.08% under the optimum conditions of the independent variables (adsorption time 6.7 h, pH of the solution 6.4, initial EE2 concentration 0.98 mg L−1, and the adsorbent dose 88.9 mg L−1) was very close to the experimental value (95.34%). pH showed the highest level of significance with the percent contribution (63.86%) as compared to other factors. The interactive influences of pH and initial concentration on EE2 adsorption efficiency were significant (p < 0.05). The goodness of fit of the model was checked by the coefficient of determination (R2) between the experimental and predicted values of the response variable. The response surface methodology successfully reflects the impact of various factors and optimized the process variables for EE2 adsorption. The kinetic adsorption data for EE2 fitted well with a pseudo-second-order model, while the equilibrium data followed Langmuir isotherms. Thermodynamic analysis indicated that the adsorption was a spontaneous and endothermic process. Therefore, Fe3O4@Ti3C2 composite present the outstanding capacity to be employed in the remediation of EE2 contaminated wastewaters.


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