scholarly journals Application of response surface methodology for optimization of oxytetracycline hydrochloride degradation using hydrogen peroxide/polystyrene-supported iron phthalocyanine oxidation process

2020 ◽  
Vol 81 (6) ◽  
pp. 1308-1318
Author(s):  
Yue Sun ◽  
Xinlei Feng ◽  
Shun Fu
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
Axial Ligand ◽  
Active Species ◽  
Iron Phthalocyanine ◽  
Paramagnetic Resonance ◽  
Initial Ph ◽  
Novel Catalyst

Abstract Inspired by metalloporphyrin-based enzymes, a biomimetic catalyst, R-N-Fe, was prepared by grafting iron phthalocyanine (FePc) covalently onto a macroporous chloromethylated polystyrene-divinylbenzene resin (R), which was pre-functionalized using 4-aminopyridine (4-ampy) as an axial ligand. The novel catalyst was used for the degradation of oxytetracycline hydrochloride (OTCH). The response surface methodology was employed to optimize the independent operating parameters, including temperature, catalyst amount, H2O2 dosage, and initial pH value. The results displayed that the initial pH and temperature had the most significant effect on the removal efficiency. Under optimum conditions, the OTCH removal efficiency was 93.98%. Additionally, the classical quenching experiment and electron paramagnetic resonance (EPR) test indicated that R-N-Fe could generate hydroxyl radicals by decomposing H2O2, which was the main active species for eliminating OTCH. Furthermore, R-N-Fe can be easily recycled and can maintain high stability in the reusability test, rendering it a good potential for practical application.

Electrocoagulation and nanofiltration integrated process application in purification of bilge water using response surface methodology

2016 ◽  
Vol 74 (3) ◽  
pp. 564-579 ◽  
Author(s):  
Ceyhun Akarsu ◽  
Yasin Ozay ◽  
Nadir Dizge ◽  
H. Elif Gulsen ◽  
Hasan Ates ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Cod Removal ◽  
Positive Sign ◽  
Aluminum Electrode ◽  
Integrated Process ◽  
Bilge Water ◽  
Cod Removal Efficiency ◽  
Initial Ph

Marine pollution has been considered an increasing problem because of the increase in sea transportation day by day. Therefore, a large volume of bilge water which contains petroleum, oil and hydrocarbons in high concentrations is generated from all types of ships. In this study, treatment of bilge water by electrocoagulation/electroflotation and nanofiltration integrated process is investigated as a function of voltage, time, and initial pH with aluminum electrode as both anode and cathode. Moreover, a commercial NF270 flat-sheet membrane was also used for further purification. Box–Behnken design combined with response surface methodology was used to study the response pattern and determine the optimum conditions for maximum chemical oxygen demand (COD) removal and minimum metal ion contents of bilge water. Three independent variables, namely voltage (5–15 V), initial pH (4.5–8.0) and time (30–90 min) were transformed to coded values. The COD removal percent, UV absorbance at 254 nm, pH value (after treatment), and concentration of metal ions (Ti, As, Cu, Cr, Zn, Sr, Mo) were obtained as responses. Analysis of variance results showed that all the models were significant except for Zn (P > 0.05), because the calculated F values for these models were less than the critical F value for the considered probability (P = 0.05). The obtained R2 and Radj2 values signified the correlation between the experimental data and predicted responses: except for the model of Zn concentration after treatment, the high R2 values showed the goodness of fit of the model. While the increase in the applied voltage showed negative effects, the increases in time and pH showed a positive effect on COD removal efficiency; also the most effective linear term was found as time. A positive sign of the interactive coefficients of the voltage–time and pH–time systems indicated synergistic effect on COD removal efficiency, whereas interaction between voltage and pH showed an antagonistic effect.

scholarly journals Application of electrochemical peroxidation (ECP) process for waste-activated sludge stabilization and system optimization using response surface methodology (RSM)

2018 ◽  
Vol 77 (6) ◽  
pp. 1765-1776 ◽  
Author(s):  
Gagik Badalians Gholikandi ◽  
Khashayar Kazemirad
Keyword(s):  
Response Surface Methodology ◽  
Activated Sludge ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
System Optimization ◽  
Waste Activated Sludge ◽  
Operational Conditions ◽  
Sludge Stabilization ◽  
Rsm Optimization

Abstract In this study, the performance of the electrochemical peroxidation (ECP) process for removing the volatile suspended solids (VSS) content of waste-activated sludge was evaluated. The Fe2+ ions required by the process were obtained directly from iron electrodes in the system. The performance of the ECP process was investigated in various operational conditions employing a laboratory-scale pilot setup and optimized by response surface methodology (RSM). According to the results, the ECP process showed its best performance when the pH value, current density, H2O2 concentration and the retention time were 3, 3.2 mA/cm2, 1,535 mg/L and 240 min, respectively. In these conditions, the introduced Fe2+ concentration was approximately 500 (mg/L) and the VSS removal efficiency about 74%. Moreover, the results of the microbial characteristics of the raw and the stabilized sludge demonstrated that the ECP process is able to remove close to 99.9% of the coliforms in the raw sludge during the stabilization process. The energy consumption evaluation showed that the required energy of the ECP reactor (about 1.8–2.5 kWh (kg VSS removed)−1) is considerably lower than for aerobic digestion, the conventional waste-activated sludge stabilization method (about 2–3 kWh (kg VSS removed)−1). The RSM optimization process showed that the best operational conditions of the ECP process comply with the experimental results, and the actual and the predicted results are in good conformity with each other. This feature makes it possible to predict the introduced Fe2+ concentrations into the system and the VSS removal efficiency of the process precisely.

Evaluation of heterogeneous photo-Fenton oxidation of Orange II using response surface methodology

2010 ◽  
Vol 62 (6) ◽  
pp. 1320-1326 ◽  
Author(s):  
Y. H. Gong ◽  
H. Zhang ◽  
Y. L. Li ◽  
L. J. Xiang ◽  
S. Royer ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Heterogeneous Catalyst ◽  
Uv Irradiation ◽  
Heterogeneous Catalysts ◽  
Ph Value ◽  
Dye Degradation ◽  
High Catalytic Activity ◽  
Orange Ii ◽  
Initial Ph

A mesoporous SBA-15 doped iron oxide (Fe2O3/SBA-15) was synthesized by co-codensation, characterized and used as heterogeneous catalysts for the photo-Fenton decolorization of azo dye Orange II under UV irradiation. Response surface methodology (RSM) was used to investigate operating condition effects, such as hydrogen peroxide concentration, initial pH and catalyst loadings, on the decolorization rate. UV irradiation is found to enhance the activity of the catalyst in the process. RSM analysis evidenced the influence of the initial pH value and H2O2 concentration on the dye degradation rate. The coupled UV/Fe2O3/SBA-15/H2O2 process at room temperature is revealed as a promising friendly process for wastewater treatment. Indeed, the use of a heterogeneous catalyst allows an easy active phase recycling without multi-step recovering while the heterogeneous catalyst used here exhibits high catalytic activity for the reaction considered.

scholarly journals Optimization of electrocoagulation of instant coffee production wastewater using the response surface methodology

2017 ◽  
Vol 19 (2) ◽  
pp. 67-71 ◽  
Author(s):  
Ha Manh Bui
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Current Density ◽  
Cod Removal ◽  
Coefficient Of Determination ◽  
Electrolysis Time ◽  
Instant Coffee ◽  
Operating Variables ◽  
Initial Ph

Abstract The COD removal efficiency from an instant coffee processing wastewater using electrocoagulation was investigated. For this purpose, the response surface methodology was employed, using central composing design to optimize three of the most important operating variables, i.e., electrolysis time, current density and initial pH. The results based upon statistical analysis showed that the quadratic models for COD removal were significant at very low probability value (<0.0001) and high coefficient of determination (R2 = 0.9621) value. The statistical results also indicated that all the three variables and the interaction between initial pH and electrolysis time were significant on COD abatement. The maximum predicted COD removal using the response function reached 93.3% with electrolysis time of 10 min, current density of 108.3 A/m2 and initial pH of 7.0, respectively. The removal efficiency value was agreed well with the experimental value of COD removal (90.4%) under the optimum conditions.

Optimum Conditions of Ag/BiVO4 Photocatalytic Performance on Degradation of Paracetamol by Response Surface Methodology

2014 ◽  
Vol 1073-1076 ◽  
pp. 336-339
Author(s):  
Tian Qi Li ◽  
Hui Wang ◽  
Ya Qi Zhu ◽  
Zhao Yong Bian
Keyword(s):  
Response Surface Methodology ◽  
Visible Light ◽  
Response Surface ◽  
Visible Light Irradiation ◽  
Ph Value ◽  
Light Irradiation ◽  
Catalyst Loading ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Ag Catalyst

Response surface methodology was applied to investigate the optimum degradation conditions of paracetamol using Ag/BiVO4 photocatalysts under the visible light irradiation. Experimental results show that the optimum degradation conditions were: catalyst dosage quantity was 80 mg, Ag-catalyst loading was 5%, and the initial pH value of the solution was 6, respectively. Under this condition, the degradation efficiency of paracetamol was 77.9% within 5 h under the visible light irradiation.

Optimization of Coagulation Process for Disperse Navy Blue Dye Wastewater Treatment Using Response Surface Methodology

2014 ◽  
Vol 977 ◽  
pp. 270-273
Author(s):  
Ming Li ◽  
Yan Zhen Yu ◽  
Guang Yong Yan
Keyword(s):  
Response Surface Methodology ◽  
Wastewater Treatment ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
Settling Time ◽  
Blue Dye ◽  
Dye Wastewater ◽  
Coagulation Process ◽  
Coagulant Dosage

A response surface methodology (RSM) was used for the determination of optimum coagulation process conditions for disperse navy blue dye wastewater treatment. The experimental design was Box-Behnken design (BBD) with three operational variables: coagulant dosage, pH value and settling time. The influence of these three independent variables on the chroma removal was evaluated using a second-order polynomial multiple regression model. Quadratic model was predicted for the response variable and the maximum model-predicted chroma removal efficiency was 95%. Based on surface and contour plots, the optimum conditions were obtained to be coagulant dosage of 70.98 mg/L, pH value of 7.46, and settling time of 15.80 min with the actual chroma removal efficiency as 93%.

scholarly journals Treatment of Zn2+ in wastewater by sinusoidal alternating current coagulation: response surface methodology and removal mechanism

2020 ◽  
Vol 82 (9) ◽  
pp. 1950-1960
Author(s):  
Yihui Zhou ◽  
Tao Xu ◽  
Jinhua Ou ◽  
Gege Zou ◽  
Xiping Lei ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Energy Consumption ◽  
Response Surface ◽  
Removal Efficiency ◽  
Current Density ◽  
Alternating Current ◽  
Initial Ph ◽  
Freundlich Adsorption Isotherm ◽  
Pseudo Second Order ◽  
Main Component

Abstract A novel sinusoidal alternating current coagulation (SACC) technique was used to remove the Zn2+ from wastewater in the present study. The response surface methodology was used to analyze the effect of current density, time, initial pH and initial Zn2+ concentration in order to obtain the optimum removal efficiency and to lower energy consumption. The results show that SACC with a current density of 0.31 A·m−2 applied to treat wastewater containing 120 mg·dm−3 Zn2+ at pH = 9 for 21.3 min can achieve a removal efficiency of Zn2+ of 98.80%, and the energy consumption is 1.147 kWh·m−3. The main component of flocs produced in SACC process is Fe5O7OH·4H2O (HFO). Large specific surface area and good adsorption performance of HFO are demonstrated. There is strong interaction between Zn2+ and HFO. Zn2+ is adsorbed and trapped by HFO and then co-precipitated. Freundlich adsorption isotherm model and pseudo-second order kinetics model explained the Zn2+ adsorption behavior well. The Zn2+ adsorption on HFO is an endothermic and spontaneous process.

scholarly journals OPTIMIZATION OF RED PIGMENT PRODUCTION BY MONASCUS PURPUREUS FTC 5356 USING RESPONSE SURFACE METHODOLOGY

2018 ◽  
Vol 19 (1) ◽  
pp. 34-47 ◽  
Author(s):  
Farhan M. Said ◽  
Nor Farhana Binti Hamid
Keyword(s):  
Response Surface Methodology ◽  
Moisture Content ◽  
Response Surface ◽  
Ph Value ◽  
Initial Moisture Content ◽  
Pigment Production ◽  
Monascus Purpureus ◽  
Red Pigment ◽  
Design Expert ◽  
Initial Ph

Factors such as environmental conditions and nutrients are significant for successful growth and reproduction of microorganisms. Manipulations of the factors are the most effective way to stimulate the growth of the microorganism, which can be used to optimize the yield of a product. In this study, Central Composite Design (CCD) of Response Surface Methodology (RSM) was used to optimize the production of red pigment by Monascus purpureus FTC 5356 using the petioles of oil palm fronds (OPF) as a substrate in solid state fermentation (SSF). The data was analyzed using Design Expert Software. The optimum combination predicted via RSM was confirmed through experimental work. The interactions between three variables such as initial moisture content (%), initial pH value (pH), and peptone concentration (%) were studied and modelled. The statistical analysis of the results showed that the optimal conditions for red pigment production 47 AU/g with the biomass of 425.1 mg/g was at 55% initial moisture content, 3% of peptone, and at pH 3.  The RSM results showed that the initial pH value had a significant effect on red pigment production (P-value <0.05). The validation of these results was also conducted by fermentation with predicted conditions and it was found that there was a discrepancy of 0.39% between the values of the experimental result and those of the predicted values. ABSTRAK: Keadaan persekitaran dan nutrien merupakan faktor-faktor penting dalam pertumbuhan mikroorganisma. Manipulasi faktor-faktor tersebut adalah kaedah terbaik bagi meningkatkan pertumbuhan mikroorganisma dan mengoptimumkan penghasilan produk. Kajian ini mengguna pakai Rekaan Gabungan Pusat (CCD) melalui Kaedah Tindak balas Permukaan (RSM) bagi penghasilan pigmen merah optimum oleh Monascus purpureus FTC 5356 menggunakan batang pelepah kelapa sawit (OPF) sebagai perumah dalam proses penapaian pepejal (SSF). Data telah dianalisis menggunakan perisian Design Expert. Gabungan parameter optimum seperti cadangan RSM telah disahkan secara eksperimen. Interaksi antara tiga pemboleh ubah seperti kandungan lembapan awal (%), nilai pH awal (pH), dan kepekatan pepton (%) telah dikaji dan dimodelkan. Analisis statistik menunjukkan penghasilan optimal pigmen merah adalah pada 47 AU/g dengan biomas sebanyak 425.1 mg/g, pada 55% lembapan awal, 3% pepton dan pada pH 3. Hasil keputusan RSM menunjukkan pH awal memberikan kesan signifikan kepada penghasilan pigmen merah (nilai P <0.05). Pengesahan analisis juga telah dijalankan melalui proses penapaian dan hasil ujikaji mendapati 0.39% lebih tinggi daripada nilai jangkaan.

Parametric and energy consumption optimization of Basic Red 2 removal by electrocoagulation/egg shell adsorption coupling using response surface methodology in a batch system

2015 ◽  
Vol 73 (11) ◽  
pp. 2572-2582 ◽  
Author(s):  
Helder Pereira de Carvalho ◽  
Jiguo Huang ◽  
Meixia Zhao ◽  
Gang Liu ◽  
Xinyu Yang ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Energy Consumption ◽  
Reaction Time ◽  
Response Surface ◽  
Removal Efficiency ◽  
Current Density ◽  
Batch System ◽  
Energy Consumption Optimization ◽  
Initial Ph ◽  
Rsm Model

In this study, response surface methodology (RSM) model was applied for optimization of Basic Red 2 (BR2) removal using electrocoagulation/eggshell (ES) coupling process in a batch system. Central composite design was used to evaluate the effects and interactions of process parameters including current density, reaction time, initial pH and ES dosage on the BR2 removal efficiency and energy consumption. The analysis of variance revealed high R2 values (≥85%) indicating that the predictions of RSM models are adequately applicable for both responses. The optimum conditions when the dye removal efficiency of 93.18% and energy consumption of 0.840 kWh/kg were observed were 11.40 mA/cm2 current density, 5 min and 3 s reaction time, 6.5 initial pH and 10.91 g/L ES dosage.

scholarly journals UV-Enhanced NaClO Oxidation of Nitric Oxide from Simulated Flue Gas

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Shao-long Yang ◽  
Zhi-tao Han ◽  
Jing-ming Dong ◽  
Zi-sheng Zheng ◽  
Xin-xiang Pan
Keyword(s):  
Removal Efficiency ◽  
Uv Irradiation ◽  
Flue Gas ◽  
Ph Value ◽  
Irradiation Time ◽  
Reaction Chamber ◽  
Active Species ◽  
Chlorine Concentration ◽  
No Removal ◽  
Initial Ph

A wet de-NOxtechnique based on an UV-enhanced NaClO oxidation process was investigated for simulated flue gas of a diesel engine using a bench-scale reaction chamber. The effects of UV irradiation time, initial pH value, and available chlorine concentration of NaClO solution were studied, respectively. The results showed that when the UV irradiation time was 17.5 min and the initial pH value of NaClO solution was 6, NO removal efficiency of UV/NaClO solution was increased by 19.6% compared with that of NaClO solution. Meanwhile, when the available chlorine concentration of NaClO solution decreased from 0.1 wt% to 0.05 wt%, the enhancement in NO removal efficiency of UV/NaClO solution increased from 19.6% to 24%, compared with that of NaClO solution. The reaction pathways of NaClO solution photolysis and NO removal by UV/NaClO process were preliminarily discussed. The results suggested that HOCl might be the most active species that released many UV-induced photooxidants through photolysis reactions, which played an important role in NO removal process.

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