scholarly journals Simultaneous degradation of nitrogenous heterocyclic compounds by catalytic wet-peroxidation process using box-behnken design

2019 ◽  
Vol 25 (4) ◽  
pp. 488-497
Author(s):  
Vijayalakshmi Gosu ◽  
Shivali Arora ◽  
Verraboina Subbaramaiah

The present study investigates the feasibility of nitrogenous heterocyclic compounds (NHCs) (Pyridine-Quinoline) degradation by catalytic wet peroxidation (CWPO) in the presence of nanoscale zerovalent iron supported on granular activated carbon (nFe<sup>0</sup>/GAC) using statistical optimization technique. Response surface methodology (RSM) in combination with Box-Behnken design (BBD) was used to optimize the process parameters of CWPO process such as initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of pyridine (Py) and quinolone (Qn) were chosen as the main variables, and total organic carbon (TOC) removal and total Fe leaching were selected as the investigated response. The optimization of process parameters by desirability function showed the ~85% of TOC removal with process condition of initial solution pH 3.5, catalyst dose of 0.55 g/L, hydrogen peroxide concentration of 0.34 mmol, initial concentration of Py 200 mg/L and initial concentration of Qn 200 mg/L. Further, for TOC removal the analysis of variance results of the RSM revealed that all parameter i.e. initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of Py and initial concentration of Qn were highly significant according to the <i>p</i> values (<i>p</i> < 0.05). The quadratic model was found to be the best fit for experimental data. The present study revealed that BBD was reliable and effective for the determination of the optimum conditions for CWPO of NHCs (Py-Qn).

2019 ◽  
Vol 15 (3) ◽  
pp. 343-350 ◽  
Author(s):  
Lubna Abidin ◽  
Mohammad Mujeeb ◽  
Showkat R. Mir

Background: Luteolin is a flavonoid unveiling various therapeutic activities, found in Vitex negundo L. Thus, there is a need to present process parameters at which maximum amount of luteolin can be extracted from V. negundo L. leaves in “one-run”. Objective: Response surface methodology (RSM) was employed for optimizing the process parameters for the extraction of luteolin from V. negundo L. leaves. The study also compared the efficacy of various traditional and modern extraction methods for luteolin extraction. Methods: Extraction conditions (solvent to drug ratio, extraction temperature and extraction time) were optimized by RSM, Box-Behnken Design (BBD). Quantification of luteolin in various extracts was done through High Performance Liquid Chromatography (HPLC). Results: Hot solvent extraction by reflux technique stood out to be the best technique and methanol was found to be the most effective solvent for luteolin extraction.Through the use of BBD, the optimal conditions for luteolin extraction were established as: solvent to drug ratio- 17.7 mL/g, extraction temperature- 55.5°C and extraction time-2.04 hours. Under such conditions 7.32 %w/w of luteolin was yielded which was close to predicted value of 7.29 %w/w. Conclusion: Reflux technique stood out to be the best among all the studied modes of extraction and methanol proved to be the most effective solvent. Moreover, all the three variables significantly affected the luteolin extraction. Our study shows the applicability of a statistical technique, RSM in phytocompound extraction field. This makes the optimization technique cheap and less laborious than the traditional optimization method.


2018 ◽  
Vol 27 (1) ◽  
pp. 67
Author(s):  
Aldeir Pinedo ◽  
Fernando Anaya

Se ha realizado el estudio cinético de la decoloración del colorante reactivo Sunfix Yellow S4GL (RAS) empleando una disolución de 20 ppm del colorante mediante el proceso de oxidación avanzada (POA) H2O2/UV. Para ello se evaluó el efecto de la concentración inicial del peróxido de hidrógeno, el pH inicial de la solución, la concentración del colorante y la intensidad de la radiación UV‐C sobre la decoloración con el fin de optimizarlos. Los valores óptimos son los siguientes: concentración inicial de H2O2 a 3.8 x 10‐2 mol/L, pH3, concentración inicial del colorante a 20mg/L, potencia de radiación 3 lámparas con potencia de 15W de radiación UV‐C cada una. El estudio cinético de la decoloración sigue un modelo cinético de pseudo primer orden. Bajo condiciones óptimas se obtuvo un porcentaje de decoloración del 100% luego de una hora de tratamiento. Palabras clave.- decoloración, proceso de oxidación avanzada (POA), peróxido de hidrógeno, radiación UV‐C em> ABSTRACT A study of the kinetics of discoloration of a 20 ppm solution of Sunfix Yellow S4GL (RAS) reactive dye has been carried out using the H2O2/UV advanced oxidation process (AOP). To optimize the process, the effects on the discoloration of the initial concentration of hydrogen peroxide, the initial pH of the solution, the dye concentration and the intensity of the UV‐ C radiation were evaluated. The optimum values were the following: initial concentration of H2O2 a 3.8 x 10‐2 mol/L, pH3; initial dye concentration: 20 mg/L; UV radiation: 3 bulbs with 15 W of UV‐C power each. The discoloration reaction followed a pseudo first order kinetic model. Under optimum conditions, a one hour treatment yielded 100% discoloration. Keywords.- discoloration, advanced oxidation process (AOP), hydrogen peroxide, UV‐C radiation.


2015 ◽  
Vol 73 (2) ◽  
pp. 260-266 ◽  
Author(s):  
F. G. Zha ◽  
D. X. Yao ◽  
Y. B. Hu ◽  
L. M. Gao ◽  
X. M. Wang

The landfill leachate treated by sonication in presence of Fe2+ (US/Fe2+) and then by photo-Fenton achieved the highest total organic carbon (TOC) removal efficiency among the screened processes. The lower initial pH, dosage of Fe2+ and initial concentration of leachate were helpful in raising TOC removal efficiency of leachate by US/Fe2+. The optimal conditions for the US-photo-Fenton process were as follows: initial pH at 3.0, [H2O2]/[TOC0] at 2, [H2O2]/[Fe2+] at 5 and initial concentration of landfill leachate at 600 mg/L. The removal efficiency of TOC, chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD5) were 68.3, 79.6 and 58.2%, while the BOD5/COD rose from 0.20 to 0.43 at optimum condition. Based on gas chromatography–mass spectrometry (GC-MS) results, 36 of a total of 56 pollutants were completely degraded by US-photo-Fenton treatment.


2012 ◽  
Vol 66 (12) ◽  
pp. 2695-2701 ◽  
Author(s):  
Rui-Jia Lan ◽  
Ji-Tai Li ◽  
Han-Wen Sun ◽  
Wen-Bin Su

A central composite factorial design methodology was employed to optimize the degradation of naproxen (NPX) by the combination of Fenton reagent and ultrasound (US) irradiation. In this study, the variables considered for the process optimization were the hydrogen peroxide, ferrous ion and NPX initial concentrations, while ultrasonic power amplitude was adjusted at 90% and initial pH was 3. An appropriate quadratic model was developed in order to plot the response surface and contour curves. Optimum dosage of Fenton reagent for NPX removal was found to be hydrogen peroxide concentration = 9.98 mmol L−1, ferrous ion concentration = 4.83 mg L−1 while NPX concentration was equal to 20 mg L−1. A degradation efficiency of 100% was achieved within 10 min under US.


2019 ◽  
Vol 8 (5) ◽  
pp. 410-419 ◽  
Author(s):  
Kaouthar Oukili ◽  
Mohammed Loukili

Degradation of textile azo dye solutions containing Methyl Orange by anodic oxidation using an electrochemical reactor was studied. The combined effect of independent parameters (current intensity, initial pH and electrolysis time) on color removal efficiency was investigated and optimized using response surface methodology. A Box-Behnken design was successfully employed for experimental design. The obtained quadratic model was statistically tested using analysis of variance (ANOVA). Results showed that the optimal operating conditions to achieve 98.51% efficiency for color removal were current intensity = 4.6 A, initial pH= 4 and electrolysis time = 65 min, at a dye concentration and temperature of 50 mg/L and 25 °C, respectively. 


2020 ◽  
Vol 15 (2) ◽  
pp. 152-165
Author(s):  
Harekrishna Roy ◽  
Sisir Nandi ◽  
Ungarala Pavani ◽  
Uppuluri Lakshmi ◽  
Tamma Saicharan Reddy ◽  
...  

Background: The present study deals with the formulation and optimization of piroxicam fast dissolving tablets and analyzes the impact of an independent variable while selecting the optimized formulation utilizing Quality by Design (QbD) and Box-Behnken Design (BBD). Methods: Seventeen formulations were prepared by direct compression technique by altering the proportion of cross carmellose sodium, spray dried lactose and hydro propyl methyl cellulose (HPMC K4M). The BBD statistical technique was used to optimize formulations and correlate the relationship among all the variables. Also, the powder mixture characteristics and tablet physiochemical properties such as hardness, friability, drug content, Disintegration Time (DT) and dissolution test were determined using 900 ml of 0.1N HCl (pH-1.2) at 37 ± 0.5°C. Results: Significant quadratic model and second order polynomial equations were established using BBD. To find out the relationship between variables and responses, 3D response surface and 2D contour plot was plotted. A perturbation graph was also plotted to identify the deviation of the variables from the mean point. An optimized formula was prepared based on the predicted response and the resulting responses were observed to be close with the predicted value. Conclusion: The optimized formulation with the desired parameter and formulation with variables and responses can be obtained by BBD and could be used in the large experiment with the involvement of a large number of variables and responses.


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.


2021 ◽  
Vol 235 (3) ◽  
pp. 281-294
Author(s):  
Abida Kausar ◽  
Haq Nawaz Bhatti ◽  
Munawar Iqbal

Abstract Sugarcane bagasse waste biomass (SBWB) efficacy for the adsorption of Zr(IV) was investigated in batch and column modes. The process variables i.e. pH 1–4 (A), adsorbent dosage 0.0–0.3 g (B), and Zr(IV) ions initial concentration 25–200 mg/L (C) were studied. The experiments were run under central composite design (CCD) and data was analysed by response surface methodology (RSM) methodology. The factor A, B, C, AB interaction and square factor A2, C2 affected the Zr(IV) ions adsorption onto SBWB. The quadratic model fitted well to the adsorption data with high R2 values. The effect of bed height, flow rate and Zr(IV) ions initial concentration was also studied for column mode adsorption and efficiency was evaluated by breakthrough curves as well as Bed Depth Service and Thomas models. Bed height and Zr(IV) ions initial concentration enhanced the adsorption of capacity of Zr(IV) ions, whereas flow rate reduced the column efficiency.


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