scholarly journals Using BCN nanostructure as anode electrode for photoelectrocatalytic degradation of organics: a statistical approach

2021 ◽  
Author(s):  
Sadegh Ebadi ◽  
Karim Ghasemipanah ◽  
Ebrahim Alaie ◽  
Alimorad Rashidi ◽  
Alireza Khataee
Keyword(s):  
Removal Efficiency ◽  
Residence Time ◽  
Produced Water ◽  
Ph Value ◽  
Copper Wire ◽  
Cod Removal ◽  
Effective Parameters ◽  
Cod Removal Efficiency ◽  
Initial Ph ◽  
Anode Electrode

Abstract In this study, boron carbon nitride (BCN) nanostructures were used as photocatalyst which was synthesized in a chemical vapor deposition reactor. Photoelectrocatalysis was used for degradation organic pollutants from produced water. BCN nanostructures were coated on a coil-type copper wire to be as anode electrode in the photoelectrocatalytic process. The effect of different parameters on chemical oxygen demand (COD) removal efficiency from produced water was investigated by a central composite design (CCD) to maximize photoelectrocatalysis influence as one of the most used methods of wastewater treatment. A 12 run Plackett–Burman design was used for screening of the parameters (initial COD, electrical conductivity, applied cell voltage, UV lamp wavelength, H2O2 concentration, residence time, and initial pH) which led to the selection of residence time and initial pH as effective parameters. Since the core goal of this study was to maximize the COD removal efficiency, the steepest ascent method was used to propel these two parameters to the optimum region. Finally, CCD showed that applying photoelectrocatalysis could lead to 88.79% of the COD removal efficiency which would be an optimum value at a residence time of 15.85 min and a pH value of 3.3. Ultimately, this result was confirmed by experimentation at those conditions.

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 Treatment of simulated printing and dyeing wastewater using ozone microbubble

2021 ◽  
Vol 261 ◽  
pp. 04005
Author(s):  
Emmanuel Nkudede ◽  
Husseini Sulemana ◽  
Bo Zhang ◽  
Kaida Zhu ◽  
Shan Hu ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Methylene Blue ◽  
Removal Efficiency ◽  
Human Life ◽  
Cod Removal ◽  
Dyeing Wastewater ◽  
Flow Rates ◽  
Printing And Dyeing Wastewater ◽  
Cod Removal Efficiency ◽  
Initial Ph

Owing to its widespread and persistent usage, methylene blue (MB) is an environmental substance, mostly found in the printing and dyeing industry that raises concerns in the environment recently by posing significant threat to human life and the ecosystem as a whole. Thus, there is the need to effectively manage and treat the wastewater from these industries before reaching to the available water sources. Ozonation treatment is very efficient in treating printing and dyeing wastewater (MB) and can be greatly improved by using micro-bubble technology. Microbubble dissolution is an effective way to improve the rate of ozone mass transfer. To discover these properties, a method was used to improve the mass transfer of ozone microbubbles, which was used to effectively treat simulated printing and dyeing wastewater. We investigated the effects of pH, water temperature, ozone flow, and other conditions on the dissolution and attenuation properties of ozone in methylene blue microbubble solutions. Treatment of simulated printing and dyeing wastewater (methylene blue) was investigated under various initial pH and ozone flow rates. A catalytic exhibition was performed towards the decolorization of methylene blue (MB) concentrations and the corresponding COD removal efficiency. Ozone depletion and pH levels played key roles in MB degradation. Under high pH level of 11.01, the rate of removal of COD was 93.5%. Ozone dosage also has direct effect on COD removal efficiency and decolorization. Higher ozone flow rates, 0.4 L/min and 0.5 L/min recorded more than 94% degradation of COD thus very effective and efficient. Also, ozone flow rates 0.3 L/min, 0.4 L/min and 0.5 L/min with initial pH, 7.03, 6.63 and 6.36 decreased to 3.43, 3.49 and 3.44 after reaction processes which clearly shows that with high ozone dosage, pH reduces considerably.

The Pulse Electrolysis Treatment of Waste Emulsion Orthogonal Experimental Study

2013 ◽  
Vol 303-306 ◽  
pp. 2616-2619
Author(s):  
Xiao Yan Sun ◽  
Pei Dao Pan ◽  
Jang Jie Wang
Keyword(s):  
Experimental Study ◽  
Removal Efficiency ◽  
Current Density ◽  
Pulse Width ◽  
Ph Value ◽  
Operating Conditions ◽  
Cod Removal ◽  
Pulse Electrolysis ◽  
Cod Removal Efficiency ◽  
Plate Distance

This mechanical processing waste emulsion for the study, handled by pulse electrolysis. Arrangements by orthogonal testing, experimental study on plate distance (d), current density (i), the pH value and the pulse width (tP) impact on COD removal efficiency, very poor analysis of test data to determine various factors affecting the COD removal efficiency of primary and secondary sort: pH value > current density > pulse width > plate distance, optimal operating conditions. Orthogonal experimental data derived from regression analysis, determination of cross of quadratic polynomial regression equations, mathematical model. Tests confirmed that pulse electrochemical method for treatment of waste emulsion with low energy consumption, short response time, and other advantages, strong applicability of wastewater, building mathematical models, providing theoretical basis for subsequent design.

scholarly journals Effect of Current and Initial pH on Electrocoagulation in Treating the Distillery Spent Wash with Very High Pollutant Content

Water ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 11
Author(s):  
Iqbal Syaichurrozi ◽  
Sarto Sarto ◽  
Wahyudi Budi Sediawan ◽  
Muslikhin Hidayat
Keyword(s):  
Removal Efficiency ◽  
Cod Removal ◽  
Kinetic Constants ◽  
Spent Wash ◽  
Distillery Spent Wash ◽  
Removal Process ◽  
Cod Removal Efficiency ◽  
Working Volume ◽  
Initial Ph ◽  
Very High

The distillery spent wash (DSW) from bioethanol industries has a very high chemical oxygen demand (COD). Hence, the goal of this study is to investigate the effect of currents (2.5, 3 and 3.5 A) and initial pHs (4.4, 5.0 and 7.0) on electrocoagulation (EC) to decrease the COD in DSW. The results showed that the EC at the current of 3.5 A enabled a higher COD removal efficiency (74.9%) than those at the currents of 2.5 (35.4%) and 3 A (60.9%). Furthermore, the initial pH of 7.0 resulted in a higher COD removal efficiency than the initial pHs of 4.4 and 5.0. The solution pH and temperature increased throughout the process. The working volume was not constant due to the reactions of water reduction, evaporation and flotation. Scum and sludge productions were also monitored during the process. Then, the measured data (COD, sludge and scum) were used in the modeling. The simple mechanistic models were successfully built and applied to simulate the data in mass units with two different routes of process. Route 1 assumed that the COD was converted to sludge and then the latter was converted to scum. Route 2 assumed that the COD was converted to the sludge and scum at the same time. When the EC was operated at the initial pH of 4.4, the COD removal process followed route 1, but that at the initial pHs of 5.0 and 7.0, the COD removal process followed route 2. The higher the current applied in the EC, the higher the kinetic constants of ka and kb. Additionally, the higher the initial pH set, the higher the kinetic constants were. This showed that the formation rates of sludge and scum at the higher currents or initial pHs were faster than those at the lower values.

Treatment of oil–water emulsion from the machinery industry by Fenton's reagent

2015 ◽  
Vol 71 (12) ◽  
pp. 1884-1892 ◽  
Author(s):  
Chao Feng ◽  
Henghu Sun ◽  
Suqin Li ◽  
Mary Kay Camarillo ◽  
William T. Stringfellow ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Cod Removal ◽  
Oxidation Time ◽  
Single Factor ◽  
Water Emulsion ◽  
Machinery Industry ◽  
Cod Removal Efficiency ◽  
Initial Ph ◽  
Oil Water ◽  
Chinese Standard

An oil–water emulsion from the machinery industry was treated using Fenton's reagent. The objective was to reduce the high chemical oxygen demand (COD) of this waste stream so that it would meet the COD effluent limit of Chinese Standard JS-7740-95. The optimal [H2O2]/[Fe2+] ratio for COD removal was 3. An orthogonal experimental design was developed based on the optimal [H2O2]/[Fe2+] ratio to evaluate the significance of four parameters relevant to the treatment process, namely, H2O2 dosage, initial pH, oxidation time and coagulation pH. The influence of the four parameters on COD removal efficiency decreased as follows: H2O2 dosage > oxidation time > coagulation pH > initial pH. The COD removal efficiency was further investigated based on the most important single-factor parameter, which was H2O2 dosage, as discovered in the orthogonal test. A well-fitted empirical correlation was obtained from the single-factor analysis and up to 98% COD removal was attained using 50 mM H2O2. Using the doses and conditions identified in this study, the treated oil–water emulsion can be discharged according to Chinese Standard JS-7740-95.

scholarly journals Automotive fleet repair facility wastewater treatment using air/ZVI and air/ZVI/H2O2 processes

2017 ◽  
Vol 43 (3) ◽  
pp. 24-31 ◽  
Author(s):  
Jan Paweł Bogacki ◽  
Hussein Al-Hazmi
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Treatment Effectiveness ◽  
Ph Value ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Process Time ◽  
Process Conditions ◽  
Cod Removal Efficiency ◽  
Repair Facility

AbstractAdvanced automotive fleet repair facility wastewater treatment was investigated with Zero-Valent Iron/Hydrogen Peroxide (Air/ZVI/H2O2) process for different process parameters: ZVI and H2O2doses, time, pH. The highest Chemical Oxygen Demand (COD) removal efficiency, 76%, was achieved for ZVI/H2O2doses 4000/1900 mg/L, 120 min process time, pH 3.0. COD decreased from 933 to 227 mg/L. In optimal process conditions odor and color were also completely removed. COD removal efficiency was increasing with ZVI dose. Change pH value below and over 3.0 causes a rapid decrease in the treatment effectiveness. The Air/ZVI/H2O2process kinetics can be described as d[COD]/dt = −a [COD]tm, where ‘t’ corresponds with time and ‘a’ and ‘m’ are constants that depend on the initial reagent concentrations. H2O2influence on process effect was assessed. COD removal could be up to 40% (560 mg/L) for Air/ZVI process. The FeCl3coagulation effect was also evaluated. The best coagulation results were obtained for 700 mg/L Fe3+dose, that was slightly higher than dissolved Fe used in ZVI/H2O2process. COD was decreased to 509 mg/L.

Study on Treatment of Polytetrahydrofuran Wastewater by Iron-Carbon Micro Electrolysis

2013 ◽  
Vol 295-298 ◽  
pp. 1307-1310
Author(s):  
Xi Tian ◽  
Ming Xin Huo ◽  
De Jun Bian ◽  
Sheng Shu Ai ◽  
Qing Kai Ren
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Contact Time ◽  
Ph Value ◽  
Removal Rate ◽  
Volume Ratio ◽  
Cod Removal ◽  
Electrolysis Process ◽  
Cod Removal Efficiency ◽  
Cod Removal Rate

The wastewater produced from the polytetrahydrofuran (PolyTHF) was treated with iron-carbon micro electrolysis process. This paper had studied the COD removal efficiency influences of primary PH value, reaction time, the quality ratio of the iron-carbon, the quality and volume ratio of Fe-wastewater. The results show that when pH value is 3, the quality ratio of the iron-carbon is 11 and the quality and volume ratio of Fe and wastewater is 17 with contact time of 90 min, the wastewater COD removal rate can reach as high as 95.0%.

Catalytic oxidation and spectroscopic analysis of simulated wastewater containing acid chrome blue K by using chlorine dioxide as oxidant

2010 ◽  
Vol 61 (8) ◽  
pp. 1931-1940 ◽  
Author(s):  
Fengjun Yu ◽  
Laishun Shi
Keyword(s):  
Activated Carbon ◽  
Catalytic Oxidation ◽  
Removal Efficiency ◽  
Chlorine Dioxide ◽  
Ph Value ◽  
Catalyst Support ◽  
Chemical Oxidation ◽  
Cod Removal ◽  
Cod Removal Efficiency ◽  
Acid Chrome Blue K

An activated carbon-MnO2 catalyst was prepared by the dipping-calcination method using activated carbon as catalyst support. The catalyst was used for the catalytic oxidation of simulated acid chrome blue K wastewater. The COD removal efficiency and decolor efficiency by catalytic oxidation are 72.0% and 87.8%, respectively, at the condition of wastewater's COD is 2,418 mg/L, the optimum pH value is 1.2, the dosage of chlorine dioxide is 1,200 mg/L, the dosage of activated carbon-MnO2 catalyst is 4 g by reacting 50 min. The COD removal efficiency by catalytic oxidation is great than that of chemical oxidation. The COD removal efficiency only decreased a little after the catalyst used 8 times. The FTIR spectra indicate that the active ingredient of manganese dioxide is linked with activated carbon by chemical bond, not merely mechanical blending. The intermediates during the degradation process were obtained by using online infrared spectrum analysis. The degradation reaction mechanism of acid chrome blue K by chlorine dioxide oxidation was proposed based upon the experiment evidence.

Remediation of Contaminated Surface Water by Permeable Reactive Barriers (PRBs): Lab-Scale Experiments with Four Industrial Wastes as Reactive Media

2013 ◽  
Vol 295-298 ◽  
pp. 1850-1854
Author(s):  
Li Cui ◽  
Rui Gao ◽  
Fang Qin Cheng ◽  
Jian Feng Li ◽  
Xu Ming Wang
Keyword(s):  
Fly Ash ◽  
Removal Efficiency ◽  
Steel Slag ◽  
Cod Removal ◽  
Permeable Reactive Barriers ◽  
Industrial Wastes ◽  
Column Tests ◽  
Cod Removal Efficiency ◽  
Initial Ph ◽  
Reactive Media

Four industrial wastes: iron scraps, ceramsite, fly ash and steel slag were studied as reactive media for COD removal from the Fenhe River. Leaching tests demonstrated that iron scraps and ceramsite were relatively stable compared to steel slag and fly ash. Ca2+ was the main leaching ion. Batch experiment results showed that iron scraps and steel slag had better COD removal efficiency than ceramsite and fly ash. It was also found that the initial pH was important for COD removal and the COD removal efficiency of iron scraps was linearly correlated with the initial pH (R2=0.982). Compared to batch experiments, COD removal was much higher in column tests, which were about 70%, 54%, 46% for iron scraps, steel slag and ceramsite respectively.

Photocatalytic degradation of wastewater from manufactured fiber by titanium dioxide suspensions in aqueous solution: a feasibility study

2000 ◽  
Vol 42 (5-6) ◽  
pp. 95-99 ◽  
Author(s):  
Y.H. Hsieh ◽  
K.H. Wang ◽  
R.C. Ko ◽  
C.Y. Chang
Keyword(s):  
Titanium Dioxide ◽  
Removal Efficiency ◽  
Biological Treatment ◽  
Ph Value ◽  
Cod Removal ◽  
Cod Removal Efficiency ◽  
Fiber Plant ◽  
Decreasing Ph ◽  
Pre Treatment ◽  
Raw Wastewater

This investigation used wastewater from manufactured fiber plant for studying the effect of controlling variables on the COD removal efficiency by photocatalyzed degradation of organic pollutants in the presence of titanium dioxide catalyst. By using BOD/COD ratio as index, the treatment of raw wastewater was evaluated for its change of biodegradability as a feasibility in the pre-treatment of biological treatment. The experimental results indicated that with the Janssen Chemica TiO2 as catalyst, the optimal addition was 0.25 g/L with increasing COD removal for decreasing pH value. Both increased light intensity and continuous aeration increased COD removal efficiency, particularly under continuous aeration for significantly raising the ratio of BOD/COD to improve efficiency of subsequent biological treatment.

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