scholarly journals OPTIMIZATION OF LEVOFLOXACIN REMOVAL FROM AQUEOUS SOLUTION USING ELECTROCOAGULATION PROCESS BY RESPONSE SURFACE METHODOLOGY

2021 ◽  
Vol 52 (1) ◽  
pp. 204-217
Author(s):  
Mohammed & Mohammed-Ridha
Keyword(s):  
Aqueous Solution ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Correlation Coefficient ◽  
Iron Hydroxide ◽  
Second Order ◽  
Experimental Results ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
Good Agreement

This study was aimed to investigate the response surface methodology (RSM) to evaluate the effects of various experimental conditions on the removal of levofloxacin (LVX) from the aqueous solution by means of electrocoagulation (EC) technique with stainless steel electrodes. The EC process was achieved successfully with the efficiency of LVX removal of 90%. The results obtained from the regression analysis, showed that the data of experiential are better fitted to the polynomial model of second-order with the predicted correlation coefficient (pred. R2) of 0.723, adjusted correlation coefficient (Adj. R2) of 0.907 and correlation coefficient values (R2) of 0.952. This shows that the predicted models and experimental values are in good agreement. The results of the kinetic study showed that the second-order kinetic model was in good agreement with the experimental results and suggested that the mechanism of chemisorption controlled the LVX adsorption. The experimental results indicated that the adsorption of LVX on iron hydroxide flocs follows Sips isotherm with the value of the correlation coefficient (R2) of 0.937. Sips isotherm shows that both homogenous and heterogeneous adsorption can occur.

scholarly journals Optimization of pyrocatechol violet biosorption by Robinia pseudoacacia leaf powder using response surface methodology: kinetic, isotherm and thermodynamic studies

2015 ◽  
Vol 6 (2) ◽  
pp. 333-344 ◽  
Author(s):  
Neda Khorshidi ◽  
Ali Niazi
Keyword(s):  
Response Surface Methodology ◽  
Factorial Design ◽  
Response Surface ◽  
Robinia Pseudoacacia ◽  
Freundlich Isotherm ◽  
Second Order ◽  
Full Factorial Design ◽  
Order Kinetic ◽  
Pyrocatechol Violet ◽  
Full Factorial

We have investigated the biosorption of pyrocatechol violet (PCV) from aqueous solutions by Robinia pseudoacacia tree leaves as a low-cost and eco-friendly biosorbent. A full factorial design was performed for screening the main variables and their interactions, which reduces the large total number of experiments. Results of the full factorial design (24) based on an analysis of variance (ANOVA) demonstrated that the initial PCV concentration, contact time, pH and temperature are statistically significant. Box-Behnken design, a response surface methodology, was used for further optimization of these selected factors. The ANOVA and some statistical tests such as lack-of-fit and coefficient of determination (R2) showed good fit of the experimental data to the second-order polynomial model. The Langmuir and Freundlich isotherm models were used to describe the equilibrium isotherms. Equilibrium data fitted well with the Freundlich isotherm model (R2 > 0.97). In addition, thermodynamic parameters (ΔG°, ΔH° and ΔS°) were calculated, these parameters show that the biosorption process was spontaneous (ΔG° = −2.423) and exothermic (ΔH° = −9.67). The biosorption kinetic data were fitted with the pseudo-second-order kinetic model (R2 > 0.999). These results confirm that R. pseudoacacia leaves have good potential for removal of PCV from aqueous solution.

Thermal Activation of Brazilian Smectite Clay (Primavera) and its Application for the Removal of Cadmium from Aqueous Solution

2020 ◽  
Vol 07 ◽  
Author(s):  
Marta Lígia Pereira da Silva ◽  
Tellys Lins Almeida Barbosa ◽  
Meiry Gláucia Freire Rodrigues
Keyword(s):  
Aqueous Solution ◽  
Kinetic Constant ◽  
Second Order ◽  
Order Kinetic ◽  
Experimental Conditions ◽  
X Ray ◽  
Thermally Activated ◽  
Study Results ◽  
Water Cleaning ◽  
Pseudo Second Order

Background: Region-based solutions for water cleaning could be critical to tackle the water challenges faced in enhancing the in the future. Brazilian Primavera clay is cheap, abundant, and an untested material that has the potential to be used for water cleaning. Objective: the objective of the present work was to thermally activate and characterize the Brazilian clay and then determine the potential to remove Cd2+ from an aqueous solution. Methods: Primavera clay was thermally activated at 300 oC and characterized using X ray diffraction, X-ray Spectroscopy Energy Dispersive, and N2 adsorption. Sorption equilibrium was determined using the following experimental conditions: constant pH 4.5, 5 h, and 27 oC. Langmuir, Freundlich, Dubinin-Radushkevich and Temkin isotherms models were applied in order to determine the efficiency of clay used as an adsorbent. Adsorption kinetics was analyzed using the pseudo-second-order kinetic model. Results: In this study, results revealed that even though the heat treatment did not cause profound alterations on the clay structure(smectite) and surface area (78 m2 /g), a pseudo-second-order kinetic constant of 0.5563 mg/g/min was found for the cadmium removal. Conclusion: The mathematical models of the Langmuir and Temkin showed a better fit to the experimental data. A high affinity between the cadmium and the thermally activated Primavera clay was found up to 88 % with removal efficiencies.

scholarly journals Batch Adsorption of Safranin Dye from an Aqueous Solution of Balanites aegyptiaca Seed Coats

2020 ◽  
pp. 48-54
Author(s):  
Buhari Magaji ◽  
Aisha U. Maigari ◽  
Usman A. Abubakar ◽  
Mukhtar M. Sani ◽  
Amina U. Maigari
Keyword(s):  
Aqueous Solution ◽  
Correlation Coefficient ◽  
Low Cost ◽  
Kinetic Studies ◽  
Second Order ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Seed Coats

This study was aimed at using Balanite aegyptiaca seed coats activated carbon (BAAC) as a potential adsorbent to remove safranin dye from aqueous solution. BAAC was prepared from Balanite aegyptiaca seed coats using a one-step procedure with 67.27% yield, 3.23% ash content, 695 m2/g surface area and 203 mg/g iodine number. The FTIR spectroscopy revealed O-H, N-H, C-H, C=C, C-O-H stretching vibrations. The influences of agitation time, initial dye concentration and adsorbent dose were studied in batch experiments at room temperature. The adsorptions were rapid at the first 15 minutes of agitation, with the uptake of 2.746 mg/kg. The adsorption equilibrium was achieved at 90 minutes of agitation. Kinetic studies showed good correlation coefficient for both pseudo-first order and pseudo-second-order kinetics model but fitted well into pseudo-second order kinetic model. The adsorption data fitted well into Langmuir isotherm with correlation coefficient (R2) very close to unity and Langmuir maximum adsorption constant, qm  1.00. Thus, the fitting into Langmuir indicates monolayer coverage on the adsorbents. The results showed that BAAC has the potential to be applied as alternative low-cost adsorbents in the remediation of dye contamination in wastewater.

scholarly journals Assessment of TiO2 Nanoconcentration and Twin Impingement Jet of Heat Transfer Enhancement—A Statistical Approach Using Response Surface Methodology

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 595
Author(s):  
Mahir Faris Abdullah ◽  
Rozli Zulkifli ◽  
Hazim Moria ◽  
Asmaa Soheil Najm ◽  
Zambri Harun ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Response Surface Methodology ◽  
Response Surface ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Tio2 Nanoparticle ◽  
Experimental Results ◽  
Improvement Rate ◽  
Design Expert ◽  
Impingement Jet

Impinging jets are considered to be a well-known technique that offers high local heat transfer rates. No correlation could be established in the literature between the significant parameters and the Nusselt number, and investigation of the interactions between the correlated factors has not been conducted before. An experimental analysis based on the twin impingement jet mechanism was achieved to study the heat transfer rate pertaining to the surface plate. In the current paper, four influential parameters were studied: the spacing between nozzles, velocity, concentration of Nano solution coating and nozzle-plate distance, which are considered to be effective parameters for the thermal conductivity and the heat transfer coefficient of TiO2 nanoparticle, an X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) analysis were done, which highlighted the structure and showed that the nanosolution coated the surface homogenously. Moreover, a comparison was done for the experimental results with that of the predicted responses generated by the Design Expert software, Version 7 User’s Guide, USA. A response surface methodology (RSM) was employed to improve a mathematical model by accounting for a D-optimal design. In addition, the analysis of variance (ANOVA) was employed for testing the significance of the models. The maximum Nu of 91.47, where H = S = 1 cm; Reynolds number of 17,000, and TiO2 nanoparticle concentration of 0.5% M. The highest improvement rate in Nusselt was about 26%, achieved with TiO2 Nanoparticle, when S = 3 cm, H = 6 cm and TiO2 nanoparticle = 0.5 M. Furthermore, based on the statistical analysis, the expected values were found to be in satisfactory agreement with that of the empirical data, which was conducted by accounting for the proposed models’ excellent predictability. Multivariate approaches are very useful for researchers, as well as for applications in industrial processes, as they lead to increased efficiency and reduced costs, so the presented results of this work could encourage the overall uses of multivariate methods in these fields. Hypotheses: A comparison was done for the predicted responses generated by the Design Expert software with the experimental results and then studied to verify the following hypotheses: ► Preparation of three concentrations of TiO2 nanosolution was done and studied. ► The heat transfer rate could be increased by surface coating with TiO2 nanoparticle. ► The heat transfer could be improved by the impingement jet technique with suitable adjustments.

Synthesizing a surface-imprinted polymer based on the nanoreactor SBA-15 for optimizing the adsorption of salicylic acid from aqueous solution by response surface methodology

2021 ◽  
Vol 45 (14) ◽  
pp. 6192-6205
Author(s):  
Haiqing Xu ◽  
Yuhang Gao ◽  
Qiantu Tao ◽  
Aiping Li ◽  
Zhanchao Liu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Response Surface Methodology ◽  
Salicylic Acid ◽  
Response Surface ◽  
Molecularly Imprinted Polymer ◽  
Adsorption Property ◽  
Mesoporous Structure ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Ordered Mesoporous

The molecularly imprinted polymer prepared on the nanoreactor SBA-15 displayed excellent ordered mesoporous structure and superior adsorption property for salicylic acid.

Preparation and Aplication of Cation Adsorbent by Canada Goldenrod (Solidago canadensis L.)

2011 ◽  
Vol 396-398 ◽  
pp. 75-87
Author(s):  
Zai Fu Yang ◽  
Xiao Jing Yang ◽  
Li Hong Sun ◽  
Lian Lian Xu
Keyword(s):  
Sulfuric Acid ◽  
Cation Exchange ◽  
Agricultural Land ◽  
Reaction Medium ◽  
Volume Ratio ◽  
Second Order ◽  
Experimental Results ◽  
Solidago Canadensis ◽  
Order Kinetic ◽  
Pseudo Second Order

ABSTRACT: Cation adsorbent was prepared from the Solidago Canadensis（which are abandoned agricultural land of alien invasive plants）by Sulfuric acid esterification modified , isoamyl alcohol as reaction medium. Design L934 orthogonal experiment, the Solidago canadensis cation exchange adsorbent, the optimal preparation conditions. Experimental results show that at 15°C, concentrated sulfuric acid and amyl alcohol volume ratio of 5:6 obtained under conditions of Solidago canadensis cation exchange adsorbent for Pb(II) exchange best. The experimental results of Pb(II) adsorption onto the Solidago Canadensis based cation adsorbent showed that the best conditions are: the initial pH 5, the concentration of Pb(II) 300mg/L，the dosage of cation adsorbent 1.2mg/L and adsorption time 3h. The adsorption data were analyzed by using pseudo-first-order and pseudo-second-order kinetic models were found to follow the pseudo-second-order kinetic model.

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