The Application and Research of Electrochemical Method Treating Acid Red 3R Simulation Wastewater by Response Surface Method

2013 ◽  
Vol 295-298 ◽  
pp. 1258-1262
Author(s):  
Jun Sheng Hu ◽  
Lei Guan ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Ying Yong Duan

Using electrochemical oxidation method treats the acid red 3R simulation wastewater, investigates the influence of current density, electrolyte concentration, pH-value and aeration and their interaction on the removal rate of chroma. Through the design of Box-Benhnken Design(BBD) and the response surface analysis, the influence sequence of all variables is current density > aeration > electrolyte concentration > pH-value, the influence sequence of all interaction is electrolyte concentration-aeration > current density-aeration ,electrolyte concentration-pH value > current density-pH value > pH value-aeration > current density-electrolyte concentration. Ultimately, the optimal value is 98.4915% under the condition of current density of 6.51mA/cm2,electrolyte concentration of 0.04mol/L,pH-value of 4.17 and aeration of 0.24m3/h.

2012 ◽  
Vol 518-523 ◽  
pp. 2539-2542 ◽  
Author(s):  
Jun Sheng Hu ◽  
Jia Li Dong ◽  
Ying Wang ◽  
Lei Guan ◽  
Ying Yong Duan

By the static experiment, we studied the electrochemical oxidation process of simulated hydroquinone wastewater (concentration for 300mg•L-1) in the three-dimensional cell. Experimental inspected how various factors of the packing quality ratio, electrolysis voltage, supporting electrolyte concentration, and the initial pH value influence the effect of the removal of hydroquinone and CODCr. The results of the experiment clearly indicated with the increase of voltage applied the removal rate of hydroquinone and CODCr increased first and then decreased, finally and increased again. In the weak alkali conditions (pH=8.5), the removal rate of hydroquinone and CODCr is the highest, Electrolyte concentration and packing quality ratio to the effect of hydroquinone by electrochemical degradation is the larger. The results of the single factor analysis show that the most suitable processing conditions of simulated hydroquinone wastewater by bipolar electrocatalysis oxidation are the Na2SO4 concentration of 0.03mol•L-1, the electrolytic voltage of 6V, the initial pH value of 8.5, the packing quality ratio of 1:2. With this condition processing 3h, the removal rate of hydroquinone and CODCr reached 83.96% and 39.9%, respectively.


2011 ◽  
Vol 71-78 ◽  
pp. 3071-3074
Author(s):  
Jun Sheng Hu ◽  
Yue Li ◽  
Zhuo Wang

Based on a static experiment, this study researched the electrochemical oxidation process of simulated dye wastewater containing Acid Scarlet 3R in the two-dimensional electrolysing cell. This experiment investigated the effect of such various factors as current density, initial concentration, supporting electrolyte concentration, and the initial pH value on the color removal. The results of the experiment clearly indicated that the rate of color removal increased when the current density was increasing gradually; it decreased when the initial concentration was increasing; it originally increased and then decreased when concentration of electrolytes was increasing; alkaline condition was not conducive to the removal of color, and the effect of decolorization was better under an acid condition than under an alkaline condition. The optimum condition of disposing of dye wastewater is when the current density is 7Am/cm², electrolyte concentration is 0.04mol/L, pH=2.5, under the condition of which the color removal rate could be 96.06%.


2018 ◽  
Vol 238 ◽  
pp. 03003
Author(s):  
Yaling Li ◽  
Wenqiang Jiang ◽  
Ruyu Li

2,4,6-Trinitrophenol is a toxic aromatic nitro-compounds that widely used in pharmaceutical, chemical and pesticide production. Due to its stable structure and poor biodegradability, advanced electrocatalytic oxidation technology was selected to treat simulated wastewater. The goal of the present work is to optimize the electrolysis conditions such as current density, electrolysis pH, and electrolyte concentration. A Pt modified TiO2 electrode was chosen as the anode accompanied with a titanium electrode of the same size as the cathode The results showed that the removal efficiency of 2,4,6-Trinitrophenol was the highest when the current density was 20mA/cm2, electrolyte pH=5, electrolyte concentration was 2 g/L. Under the optimal condition, the removal rate of 2,4,6-Trinitrophenol reached 99.76% after 120 minutes electrolysis. The decay of TNP could also be described by the pseudo-first-order kinetics formula with respect to TNP concentration. Therefore, electrocatalytic oxidation technology might provide an effective method for the degradation of nitroaromatic organic compounds.


2019 ◽  
Vol 84 (7) ◽  
pp. 713-727 ◽  
Author(s):  
Jiteng Wan ◽  
Chunji Jin ◽  
Banghai Liu ◽  
Zonglian She ◽  
Mengchun Gao ◽  
...  

Even in a trace amounts, the presence of antibiotics in aqueous solution is getting more and more attention. Accordingly, appropriate technologies are needed to efficiently remove these compounds from aqueous environments. In this study, we have examined the electrochemical oxidation (EO) of sulfamethoxazole (SMX) on a Co modified PbO2 electrode. The process of EO of SMX in aqueous solution followed the pseudo-first-order kinetics, and the removal efficiency of SMX reached the maximum value of 95.1 % within 60 min. The effects of major factors on SMX oxidation kinetics were studied in detail by single-factor experiments, namely current density (1?20 mA cm-2), solution pH value (2?10), initial concentration of SMX (10?500 mg L-1) and concentration of electrolytes (0.05?0.4 mol L-1). An artificial neural network (ANN) model was used to simulate this EO process. Based on the obtained model, particle swarm optimization (PSO) was used to optimize the operating parameters. The maximum removal efficiency of SMX was obtained at the optimized conditions (e.g., current density of 12.37 mA cm-2, initial pH value of 4.78, initial SMX concentration of 74.45 mg L-1, electrolyte concentration of 0.24 mol L-1 and electrolysis time of 51.49 min). The validation results indicated that this method can ideally be used to optimize the related parameters and predict the anticipated results with acceptable accuracy.


2020 ◽  
Vol 49 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Wei Zhang ◽  
Weiwei Lv ◽  
Xiaoyan Li ◽  
Jiming Yao

Purpose In this study, the oxidative degradation performance of indigo wastewater based on electrochemical systems was explored. The decolourization degrees, removal rate of chemical oxygen demand and biochemical oxygen demand of the indigo wastewater after degradation were evaluated and optimized treatment conditions being obtained. Design/methodology/approach The single factor method was first used to select the electrolyte system and electrode materials. Then the response surface analysis based on Box–Behnken Design was chosen to determine the influence of four independent variables such as FeCl3 concentration, NaCl concentration, decolourization time and voltage on the degradation efficiency. Findings On the basis of single factor experiment, the electrode material of stainless steel was selected in the double cell, and the indigo wastewater was electrolyzed with FeCl3 and NaCl electrolytes. The process conditions of electrochemical degradation of indigo wastewater were optimized by response surface analysis: the concentration of FeCl3 and NaCl was of 16 and 9 g/L, respectively, with a decolourization time of 50 min, voltage of 10 V and decolourization percentage of 98.94. The maximum removal rate of chemical oxygen demand reached 75.46 per cent. The highest ratio of B/C was 3.77, which was considered to be more biodegradable. Research limitations/implications Dyeing wastewater is bringing out more and more pollution problems to the environment. However, there are some shortcomings in traditional technologies such as adsorption and filtration. As a kind of efficient and clean water treatment technology, electrochemical oxidation has been applied to the treatments of various types of wastewater. The decolourization and degradation of indigo wastewater is taken as an example to provide reference for the treatment of wastewater in actual plants. Practical implications The developed method provided a simple and practical solution for efficiently degrading indigo wastewater. Originality/value The method for the electrochemical oxidation technology was novel and could find numerous applications in the degradation of printing and dyeing wastewater.


2012 ◽  
Vol 518-523 ◽  
pp. 2073-2078 ◽  
Author(s):  
Qi You Liu ◽  
Yun Bo Zhang ◽  
Dong Feng Zhao ◽  
Chao Cheng Zhao

A response surface methodology was applied to optimize the bioremediation condition of hydrocarbon in soil by microbial consortium KL9-1. A four-level Box-Behnken factorial design was employed to study the relationship of independent variables and dependent variable by applying pH value, inoculation amount of microbial consortium KL9-1, ratio of nitrogen and phosphorus (N/P ) and surfactant (SDBS) concentration as independent variables (factors) and crude oil removal rate as dependent variable (response). Then the statistically significant model was obtained and numerical optimization based on desirability function was carried out for pH 7.0, inoculation amount 50.0 mL, N/P 2: 1 and SDBS concentration 4.0 g, and the hydrocarbon removal rate reached as high as 52.58%. The predictive values showed good agreement with the experimental values under the optimization conditions, by standard variance <1.3%. It showed that the optimal result was reliable.


2014 ◽  
Vol 1033-1034 ◽  
pp. 387-390
Author(s):  
Ya Jun Wang ◽  
Jin Xi Wang ◽  
Yan Juan Li ◽  
Ying Wang

The effect of several important parameters on the removal of hexavalent chromium by humic acid was evaluated using an optimal experimental design based on Box-Behnken Response Surface method. The factors included temperature、pH、initial potassium chromate concentration and adsorbent dosage. A quadratic model for predicting the optimum removal conditions was derived, and the obtained optimal parameters were temperature 51°C, pH=2.34, initial potassium chromate concentration 14.30mg/L and adsorbent 0.58g. At the optimal conditions, the maximal removal rate of hexavalent chromium reached 73.17 %( forecast value was 73.26%).


Author(s):  
Yu Li ◽  
Leigang Li ◽  
Reham Yasser Farouk ◽  
Yuanyuan Wang

Flocculation can remove large amounts of nitrogen and phosphorus from wastewater, and the resulting nitrogen- and phosphorus-rich floc can be used to produce organic fertilizer. For biogas slurries containing high levels of nitrogen and phosphorus, ordinary flocculants can no longer meet the flocculation requirements. In this study, to fully utilize the advantages of the two flocculants and achieve efficient removal rates of nitrogen and phosphorus from a biogas slurry, chitosan (CTS) and polyaluminum chloride (PAC) were used as a composite flocculation agent to flocculate pig biogas slurries. The response surface method was used to study the effect of PAC added (PACadded) to the composite flocculant (CF), composite flocculant added (CFadded) to the biogas slurry and the pH on flocculation performance, and optimize these three parameters. In the tests, when the PACadded was 6.79 g·100 mL−1CF, the CFadded was 20.05 mL·L−1 biogas slurry and the pH was 7.50, the flocculation performance was the best, with an absorbance of 0.132 at a wavelength of 420 nm. The total phosphorus (TP) concentration was reduced from 214.10 mg·L−1 to 1.38 mg·L−1 for a removal rate of 99.4%. The total ammonia nitrogen (TAN) concentration was reduced from 1568.25 mg·L−1 to 150.27 mg·L−1 for a removal rate of 90.4%. The results showed that the CF could form larger flocs, and had greater adsorption capacity and more stable flocculation performance than ordinary flocculants. Furthermore, the CF could exhibit better chelation, electrical neutralization and bridge adsorption.


Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3097 ◽  
Author(s):  
Vuppala ◽  
Chedir ◽  
Jiang ◽  
Chen ◽  
Aziz ◽  
...  

The membrane electrode assembly (MEA) plays an important role in the proton exchange membrane fuel cell (PEMFC) performance. Typically, the structure comprises of a polymer electrolyte membrane sandwiched by agglomerate catalyst layers at the anode and cathode. Optimization of various parameters in the design of MEA is, thus, essential for reducing cost and material usage, while improving cell performance. In this paper, optimization of MEA is performed using a validated two-phase PEMFC numerical model. Key MEA parameters affecting the performance of a single PEMFC are determined from sensitivity analysis and are optimized using the response surface method (RSM). The optimization is carried out at two different operating voltages. The results show that membrane thickness and membrane protonic conductivity coefficient are the most significant parameters influencing cell performance. Notably, at higher voltage (0.8 V per cell), the current density can be improved by up to 40% while, at a lower voltage (0.6 V per cell), the current density may be doubled. The results presented can be of importance for fuel cell engineers to improve the stack performance and expedite the commercialization.


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