scholarly journals Simultaneous removal of lead and copper from synthetic water by electrocoagulation and techno-economic evaluation: optimization through response surface methodology

2021 ◽  
Vol 13 (1) ◽  
pp. 61-68
Author(s):  
A.K. Varma ◽  
A. Chouhan ◽  
R. Shankar ◽  
P. Mondal ◽  
A.K. Rathore ◽  
...  

In the present study, the electrocoagulation process using iron electrodes was used to treat synthetic water containing lead and copper. Box-Behnken design of response surface methodology was applied to optimize the process variables namely initial pH, current density and treatment time along with operating cost. At optimum conditions (initial pH: 5, current density: 50 A/m2, treatment time: 40 min), the model predicted value for removal of lead and copper was found as 102.81% and 99.75%, respectively with an operating cost of 0.481 USD/m3. Whereas, the actual or experimental values of lead and copper removal were found as 99.98 % and 99.88 % as well as operating cost of 0.476 USD/m3, which signifies a good closeness between the model predicted values and actual values. The concentration of lead and copper in treated water was found below the permissible limits as per CPCB norms for industrial discharge.

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Sudesh S ◽  
Meenakshi M ◽  
Sheeja R.Y ◽  
Thanapalan Murugesan

In the present work, crab shell was used as the biosorbent to remove copper from aqueous solution. Batch experiments were performed at different initial copper concentration of copper solutions (1-40 g/l), initial pH (2-9), temperature (20-400°C), and biosorbent dosages (2-10 g/l). The maximum removal of copper using crab shell occurred at a pH of 3 and at a temperature of 400°C using an optimum biosorbent dosage of 5 g/l. A mathematical model was proposed to identify the effects of the individual interactions of these variables on the biosorption of copper. The results have been modeled using response surface methodology using a Box-Behnken design. The response surface method was developed using three levels (-1, 0, +1) with the above mentioned four factors. The second order quadratic regression model fitted the experimental data with Prob > F to be < 0.0001. The experimental values were found to be in good agreement with the predicted values, with a satisfactory correlation coefficient of R2 = 0.9999.


2016 ◽  
Vol 75 (4) ◽  
pp. 952-962 ◽  
Author(s):  
W. T. Mook ◽  
M. K. Aroua ◽  
M. Szlachta ◽  
C. S. Lee

In this work, a regression model obtained from response surface methodology (RSM) was proposed for the electrocoagulation (EC) treatment of textile wastewater. The Reactive Black 5 dye (RB5) was used as a model dye to evaluate the performance of the model design. The effect of initial solution pH, applied current and treatment time on RB5 removal was investigated. The total number of experiments designed by RSM amounted to 27 runs, including three repeated experimental runs at the central point. The accuracy of the model was evaluated by the F-test, coefficient of determination (R2), adjusted R2 and standard deviation. The optimum conditions for RB5 removal were as follows: initial pH of 6.63, current of 0.075 A, electrolyte dose of 0.11 g/L and EC time of 50.3 min. The predicted RB5 removal was 83.3% and the percentage error between experimental and predicted results was only 3–5%. The obtained data confirm that the proposed model can be used for accurate prediction of RB5 removal. The value of the zeta potential increased with treatment time, and the X-ray diffraction pattern shows that iron complexes were found in the sludge.


2017 ◽  
Vol 19 (2) ◽  
pp. 67-71 ◽  
Author(s):  
Ha Manh Bui

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.


Wood apple is a fruit, which containing many nutrient values and bioactive compounds. In the present study, The response surface methodology (RSM) was used to optimize the input variables of the spray drying process. Three coded independent variables viz. input dry substance concentration (X1 ), input flow (X2 ), spray drying temperature (X3 ), corresponds to the encoded variables Z1 (from 20 to 24 %), Z2 (from 5.35 to 6.72 mL/min.), Z3 (from 140 to 160oC). The R2 correlation coefficient between the experimental values and the predicted values from the model up to 0.967 indicated the satisfactorily of the predicted model. Three optimal input parameters to get the highest efficiency of dry matter recovery (51.80 %) were derived at Z1 = 24 %, Z2 = 5.35 mL/min., Z3 = 160oC. The powder product obtained has a good sensory quality, high contents of antioxidants and nutritional components.


2011 ◽  
Vol 396-398 ◽  
pp. 1269-1272 ◽  
Author(s):  
Mu Xin Han ◽  
Dong Mei Li ◽  
Yu Jie Feng ◽  
Yu Fei Tan

To enhance further treatment efficiency of the sludge, a process microwave drying of sludge was optimized using response surface methodology (RSM). A quadratic polynomial mathematical model was developed through Box-Behnken experimental design to describe the relationship between tested variables and moisture content of sludge. The experimental values were found to be in accordance with the predicted values, the correlation coefficient is 0.9203(P < 0.001). Estimated optimum parameters were as follows: The sludge: tree bark is 58:1, microwave power is 630w and processing time is 5.32 minutes. Under these conditions, a lowest moisture content of sludge (49.12%) after microwave drying was reached.


2020 ◽  
Vol 82 (9) ◽  
pp. 1950-1960
Author(s):  
Yihui Zhou ◽  
Tao Xu ◽  
Jinhua Ou ◽  
Gege Zou ◽  
Xiping Lei ◽  
...  

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.


2014 ◽  
Vol 3 (4) ◽  
pp. 21-33
Author(s):  
M.A. Waheed ◽  
O.D. Samuel ◽  
B.O. Bolaji ◽  
O.U. Dairo

The present work deals with the production of biodiesel from Nigerian restaurant waste cooking oil (NRWCO) and the optimization of the parameters that influences the alkaline transesterification of NRWCO into biodiesel using response surface methodology. The optimization parameters like oil: oil/methanol molar ratio, catalyst amount and reaction time were done using Design Expert 6.06 software. It was found that the maximum yield of biodiesel was obtained in 79.8 min for 1: 5.9, oil: methanol ratio, 1.2 wt. % KOH amount. A total of 20 experiments using Central Composite Design were carried out. The R2, adjusted R2 and predicted R2 values were 0.982, 0.9657 and 0.9088 respectively show that the experimental values are in good agreement with the predicted values. The properties of biodiesel at the optimized parameters, thus, produced confirm to the ASTM, EN and BIS specifications, making it an ideal alternative fuel for diesel engine.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ali Ghasemzadeh ◽  
Hawa Z. E. Jaafar

Response surface methodology was applied to optimization of the conditions for reflux extraction of Pandan (Pandanus amaryllifoliusRoxb.) in order to achieve a high content of total flavonoids (TF), total phenolics (TP), and high antioxidant capacity (AC) in the extracts. Central composite experimental design with three factors and three levels was employed to consider the effects of the operation parameters, including the methanol concentration (MC, 40%–80%), extraction temperature (ET, 40–70°C), and liquid-to-solid ratio (LS ratio, 20–40 mL/g) on the properties of the extracts. Response surface plots showed that increasing these operation parameters induced the responses significantly. The TF content and AC could be maximized when the extraction conditions (MC, ET, and LS ratio) were 78.8%, 69.5°C, and 32.4 mL/g, respectively, whereas the TP content was optimal when these variables were 75.1%, 70°C, and 31.8 mL/g, respectively. Under these optimum conditions, the experimental TF and TP content and AC were 1.78, 6.601 mg/g DW, and 87.38%, respectively. The optimized model was validated by a comparison of the predicted and experimental values. The experimental values were found to be in agreement with the predicted values, indicating the suitability of the model for optimizing the conditions for the reflux extraction of Pandan.


Author(s):  
Hariraj Singh ◽  
Brijesh Kumar Mishra ◽  
Aditya Prakash Yadav

The aim of the present work was to investigate the removal of phenol from a synthetic solution by the enhanced electrochemical oxidation process using graphite electrodes. Central composite design (CCD) and Box Behnken Design (BBD) under Response Surface Methodology (RSM) tool were used to investigate the effects of major operating variables viz. Current density (mA/ cm2): (2.27 to 4.54), pH: (5.5 to 7.5) and electrolysis time (min): (30 to 90). The predicted values of BBD responses obtained using RSM were more significant than the CCD model in terms of reaction time, whereas under the desirability test CCD model was found more appropriate in terms of phenol removal and power consumption. The optimal result shows that the CCD model predicted and experimental values of phenol removal and power consumption are 92.87 %; 0.866 kWh/m3 and 86.34 %; 1.12 kWh/m3 respectively under optimized variable conditions, current density: 2.78 mA/cm2, pH: 6.98 and electrolysis time: 88.02 minutes at high desirability level.


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