scholarly journals Applying Response Surface Methodology to optimize the decarbonization process of Timahdit oil shale

2019 ◽  
Vol 8 (5) ◽  
pp. 372-379 ◽  
Author(s):  
Laila Makouki ◽  
Meriem Tarbaoui ◽  
Samia Glissi ◽  
Said Mansouri ◽  
Hassan Hannache ◽  
...  

The present article aims to optimize the decarbonization of Timahdit oil shale layer Y by removing carbonates from the raw rock using acetic acid. The response surface methodology “central composite design (CCD)” has been used as a method of optimization to study the 3 factors of the process. The factors studied are the concentration of the acid, the processing time, and the ratio (liquid/solid). The optimal conditions with 68.17% of residue rate are obtained with 2 mol/l as concentration, 120 min as a time of treatment and 10.02 for the ratio.The raw (Y) and optimized materials (YO) were characterized by Scanning Electron Microscopy (SEM), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The results showed that the acetic acid used to remove carbonates affects the chemical composition and the texture evolution of the residues.

2021 ◽  
Vol 42 (1) ◽  
pp. 40-50
Author(s):  
P. Dhevagi ◽  
◽  
S. Priyatharshini ◽  
A. Ramya ◽  
M. Sudhakaran ◽  
...  

Aim: Removal of lead from wastewater using Azotobacter species and optimisation of various parameters to maximise the adsorption of lead by response surface methodology as a tool. Methodology: The bacterial isolate UBI-7 recovered from sewage water irrigated soil was examined for its biosorption potential towards lead. The lead removal efficiency of Azotobacter salinestris was studied with respect to metal concentration (50-250 mg l-1), contact time (24-120 hrs), and pH (4-8).Using response surface methodology, these factors were optimized and R2 value obtained was 0.9710 for lead ions, which indicates the validity of the model. Observation with Fourier Transform Infrared (FTIR), Scanning Electron Microscope imaging (SEM) and Energy Dispersive X-ray Spectroscopic analysis (EDX) were carried out to confirm lead biosorption by Azotobacter salinestris. Results: The lead tolerant bacterium isolated from sewage water irrigated soil (UBI-7) was recognized as Azotobacter salinestris by 16S rRNA based gene sequence analysis. The highest removal percentage of Pb (61.54) was 50 mg l-1 in 72 hrs equilibration period. Interaction effect between different levels of Pb and different contact time of the solution were found to be significant. Lead biosorption by the organism was confirmed by the changes in stretching intensities of functional groups as well as appearance of strong OH stretching at 3291.69 cm-1. Images obtained from Scanning Electron Microscope and Energy Dispersive X-ray Spectroscopic studies of the bacteria (UBI-7) before and after biosorption clearly indicated lead adsorption. Interpretation: Current study proves that the functional groups of Azotobacter salinestris are involved in lead biosorption from aqueous solution which was confirmed through FTIR.EDX analysis also elucidated the lead absorption by the bacterial cells. Hence, this could be effectively utilized for decontamination of lead from the polluted environment. Key words: Azotobacter salinestris, Biosorption, Lead, Response surface methodology


Author(s):  
Bao Zhang ◽  
Yunzhong Chen ◽  
Xuefei Wei ◽  
Mingqi Li ◽  
Mengjin Wang

The effects of liquid-solid ratio, acetic acid concentration and extraction time on the yield of acid-soluble collagen(ASC) from the swim bladders of grass carp were optimized by statistical analysis using response surface methodology. The response surface methodology (RSM) was used to optimize the yield of ASC by implementing the Box-Wilson design. Statistical analysis of the results showed that the linear and quadric terms of these three variables had significant effects. However, no interactions between the three variables were found to contribute to the response at a significant level. The optimal conditions for higher yield of ASC were a liquid-solid ratio of 17.85, an acetic-acid concentration of 0.54 M and a time of 34 h. Under these conditions, the model predicted an ASC yield of 8.39%. Verification of the optimization showed that an ASC yield of 8.21±0.15% was observed under the optimal conditions. The experimental values agreed with the predicted values, using analysis of variance, indicating an excellent fit of the model used and the success of response surface methodology for modeling extraction of ASC from the swim bladders of grass carp.


2017 ◽  
Vol 76 (7) ◽  
pp. 1754-1769
Author(s):  
Jun-Ming Hong ◽  
Yu-Feng Xia ◽  
Chung-Chuan Hsueh ◽  
Bor-Yann Chen

This study aimed to kinetically discover optimal conditions on characteristics of Reactive Black 5 decolorization/degradation via ferrous (Fe2+)-activated potassium persulfate (PS). Monod-like kinetics and interactive model-based response surface methodology (RSM) were applied to fitting and predict optimize treatment. Biodegradability of the intermediates was also tested by shaking culture with two species (Proteus hauseri ZMd44 and Shewanella sp. WLP72). Results showed that the optimal degradation efficiency was predicted (through RSM) as pH 3.72, (PS) = 0.39 mM, and (Fe2+) = 0.29 mM. The transformation products (dl-4-hydroxymandelic acid, benzoic acid, benzene, formic acid, oxalic acid and acetic acid) were less toxic than the original dye solution. According to those results, clean-up of dye pollutants by the Fe2+/S2O82− process is feasible as a pre-processing for the biodegradation, and the predicted optimal conditions are meaningful for further industry utilization.


2015 ◽  
Vol 72 (5) ◽  
pp. 810-816 ◽  
Author(s):  
Bin-hui Jiang ◽  
Yan Zhao ◽  
Xin Zhao ◽  
Xiao-min Hu ◽  
Li Li

With the rapid industrial development, wastewater has been a risk for environmental contamination. We aimed to explore the optimum condition and mechanism of Pb2+ bio-sorption onto Rhodotorula mucilaginosa WT6-5. Optimization of initial concentration of Pb2+, initial pH, and adsorption time for Pb2+ bio-sorption onto R. mucilaginosa WT6-5 was performed using response surface methodology. Field emission scanning electron microscopy, energy dispersive X-ray detection, X-ray fluorescence and Fourier transform infrared spectroscopy were used to analyze the mechanisms and characteristics of Pb2+ bio-sorption. A maximum Pb2+ bio-sorption capacity of 1.45 mg/g was obtained under the optimal conditions of initial concentration of Pb2+ (30 mg/L), initial pH (5.45) and adsorption time (25 minutes). Some Pb2+ remained after adsorption, and the –OH, –C=O and C–O functional groups were primarily involved in Pb2+ bio-sorption onto R. mucilaginosa WT6-5. The mechanism of Pb2+ bio-sorption involved chemical and biological actions, ion exchange and functional groups effects.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3583
Author(s):  
Junying Yang ◽  
Minye Huang ◽  
Shengsen Wang ◽  
Xiaoyun Mao ◽  
Yueming Hu ◽  
...  

In this study, a magnetic copper ferrite/montmorillonite-k10 nanocomposite (CuFe2O4/MMT-k10) was successfully fabricated by a simple sol-gel combustion method and was characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunner–Emmett–Teller (BET) method, vibrating sample magnetometer (VSM), and X-ray photoelectron spectroscopy (XPS). For levofloxacin (LVF) degradation, CuFe2O4/MMT-k10 was utilized to activate persulfate (PS). Due to the relative high adsorption capacity of CuFe2O4/MMT-k10, the adsorption feature was considered an enhancement of LVF degradation. In addition, the response surface methodology (RSM) model was established with the parameters of pH, temperature, PS dosage, and CuFe2O4/MMT-k10 dosage as the independent variables to obtain the optimal response for LVF degradation. In cycle experiments, we identified the good stability and reusability of CuFe2O4/MMT-k10. We proposed a potential mechanism of CuFe2O4/MMT-k10 activating PS through free radical quenching tests and XPS analysis. These results reveal that CuFe2O4/MMT-k10 nanocomposite could activate the persulfate, which is an efficient technique for LVF degradation in water.


2017 ◽  
Vol 864 ◽  
pp. 121-126 ◽  
Author(s):  
Farag I. Haider ◽  
Suryanto ◽  
Mohd Hanafi Ani ◽  
M.H. Mahmood

In this paper, response surface methodology (RSM) was utilized for the experiment design of CuSO4 and H2SO4 concentrations and current densities. RSM was also used to evaluate the significance of each parameter and its interaction on the adhesion strength of austenitic stainless steel substrate. Adhesion strength was investigated by a Teer ST-30 tester, and the structure of the samples investigated by using scanning electron microscopy (SEM). Results showed that increasing the concentration of CuSO4 and decreasing theat of H2SO4 strengthens adhesion. Conversely, the current density only has a slight effect.


2012 ◽  
Vol 550-553 ◽  
pp. 1866-1870
Author(s):  
Xiao Dan Tang ◽  
Hai Yang Hang ◽  
Shao Yan Wang ◽  
Jing Xiang Cong

Gypenosides III is a major bioactive component which is rich in Gynostemma pentaphyllum. For better utilization of the native resource, response surface methodology was used to optimize the extraction conditions of gypenosides III from G. pentaphyllum. The effects of three independent variables on the extraction yield of gypenosides III were investigated and the optimal conditions were evaluated by means of Box-Behnken design. The optimal conditions are as follows: ratio of ethanol to raw material 25, extraction temperature 58°C and ultrasonic time 25min. Under these conditions, the yield of gypenoside III is 1.216±0.05%, which is agreed closely with the predicted yield value.


2021 ◽  
Vol 13 (16) ◽  
pp. 9269
Author(s):  
Saddam Hussein Abo Sabah ◽  
Luis Hii Anneza ◽  
Mohd Irwan Juki ◽  
Hisham Alabduljabbar ◽  
Norzila Othman ◽  
...  

This study investigated the optimization of the bioconcrete engineering properties and durability as a response of the calcium lactate (CL) content (0.22–2.18 g/L) and curing duration (7–28 days) using the response surface methodology (RSM). Scanning electronic microscopy (SEM) was conducted to evaluate the microstructure of calcium precipitated inside the bioconcrete. The results indicated that the optimal conditions for the engineering properties of concrete and durability were determined at 2.18 g/L of CL content after 23.4 days. The actual and predicted values of the compressive strength, splitting tensile strength, flexural strength, and water absorption were 43.51 vs. 43.43, 3.19 vs. 3.19, 6.93 vs. 5.50, and 7.55 vs. 7.55, respectively, with a level of confidence exceeding 95%. The scanning electron microscope (SEM) images and energy-dispersive X-ray spectroscopy (EDX) proved that the amount of calcium increased with the increase in CL content up to 2.81 g/L at 23.4 days, reducing the pores inside the concrete and making it a great potential option for healing of concrete structures.


2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Ega Soujanya Lakshmi ◽  
Manda Rama Narasinga Rao ◽  
Muddada Sudhamani

ABSTRACT Thirty seven different colonies were isolated from decomposing logs of textile industries. From among these, a thermotolerant, grampositive, filamentous soil bacteria Streptomyces durhamensis vs15 was selected and screened for cellulase production. The strain showed clear zone formation on CMC agar plate after Gram’s iodine staining.  Streptomyces durhamensis vs15 was further confirmed for cellulase production by estimating the reducing sugars through dinitrosalicylic acid (DNS) method. The activity was enhanced by sequential mutagenesis using three mutagens of ultraviolet irradiation (UV), N methyl-N’-nitro-N-nitrosoguanidine (NTG) and Ethyl methane sulphonate (EMS). After mutagenesis, the cellulase activity of GC23 (mutant) was improved to 1.86 fold compared to the wild strain (vs15). Optimal conditions for the production of cellulase by the GC 23 strain were evaluated using Response Surface Methodology (RSM) and Artificial Neural Network (ANN). Effect of pH, temperature, duration of incubation, , and substrate concentration on cellulase production were evaluated. Optimal conditions for the production of cellulase enzyme using Carboxy Methyl Cellulase as a substrate are 55 oC of temperature, pH of 5.0 and incubation for 40 h. The cellulase activity of the mutant Streptomyces durhamensis GC23 was further optimised to 2 fold of the activity of the wild type by RSM and ANN.  


Author(s):  
I.A. Nnanwube ◽  
O.D. Onukwuli

SYNOPSIS This work focused on the prediction of optimal conditions for zinc recovery from sphalerite in a binary solution of hydrochloric acid and hydrogen peroxide. The sphalerite sample was characterized with X-ray fluorescence spectrometry (XRF), X-ray diffractometry, and Fourier transform infrared analysis (FTIR). The central composite design of response surface methodology (RSM) developed in Design Expert software and the genetic algorithm (GA) tool in matlab, were deployed for the optimization exercise. The leaching temperature, acid concentration, stirring rate, leaching time, and hydrogen peroxide concentration were defined as input variables, while zinc yield was the response. An ideal zinc yield of 90.89% could be obtained with a leaching temperature of 84.17°C, HCl concentration of 3.14 M, stirring rate of 453.08 r/min, leaching time of 107.55 minutes, and hydrogen peroxide concentration of 3.93 M using RSM; while a yield of 87.73% was obtained using GA. Analysis of the post-leaching residue revealed the presence of sulphur, zircon, fluorite, gahnite, anatase, and sylvite. Keywords: sphalerite leaching, genetic algorithm, optimization, response surface methodology.


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