scholarly journals COD removal from petrochemical wastewater by UV/hydrogen peroxide, UV/persulfate and UV/percarbonate: biodegradability improvement and cost evaluation

2016 ◽  
Vol 6 (4) ◽  
pp. 484-494 ◽  
Author(s):  
Ali Akbar Babaei ◽  
Farshid Ghanbari
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Oxygen Demand ◽  
Ultra Violet ◽  
High Strength ◽  
Cod Removal ◽  
Cost Evaluation ◽  
Petrochemical Wastewater ◽  
Ferrous Ions ◽  
Initial Ph

The petrochemical industry has been highly considered by environmentalists since it can affect the environment through the production of high strength wastewater. This study investigates chemical oxygen demand (COD) removal from petrochemical wastewater by ultra violet (UV)/oxidant systems with varying dosages of oxidants, initial pH values and reaction time. Hydrogen peroxide (H2O2), persulfate (PS) and percarbonate (PC) were used as oxidants. The results showed that pH = 3.0 was suitable for H2O2 and PC, while PS had the best performance at pH = 7.0. The presence of ferrous ions improved the removal efficiency, especially in the case of UV/PC. However, COD removal efficiencies of UV/PS and UV/H2O2 were more effective than that of the UV/PC system. The biochemical oxygen demand (BOD)/COD ratio achieved >0.4 by UV/PS/Fe2+, UV/H2O2 and UV/H2O2/Fe2+ systems. Complete decolorization occurred for all the UV/oxidant systems after only 30 min reaction time. Besides the effective performances of PS and H2O2 in COD removal, PC was considered as an inexpensive oxidant. The order of total costs based on kg COD removed was: UV/PS/Fe2+ > UV/PS > UV/H2O2/Fe2+ > UV/H2O2 > UV/PC/Fe2+ > UV/PC. In conclusion, UV/H2O2 displayed an effective, applicable and clean process for petrochemical wastewater treatment.

Optimization and statistical analysis of sono-Fenton treated wastewater of food industry using reactor by response surface method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vijay A. Juwar ◽  
Ajit P. Rathod
Keyword(s):  
Reaction Time ◽  
Response Surface ◽  
Food Industry ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Experimental Result ◽  
Molar Ratio

Abstract The present study deals with the treatment of complex waste (WW) treated for removal of chemical oxygen demand (COD) of the food industry by a sono-Fenton process using a batch reactor. The response surface methodology (RSM) was employed to investigate the five independent variables, such as reaction time, the molar ratio of H2O2/Fe2+, volume ratio of H2O2/WW, pH of waste, and ultrasonic density on COD removal. The experimental data was optimized. The optimization yields the conditions: Reaction time of 24 min, HP:Fe molar ratio of 2.8, HP:WW volume ratio of 1.9 ml/L, pH of 3.6 and an ultrasonic density of 1.8 W/L. The predicted value of COD was 91% and the experimental result was 90%. The composite desirability value (D) of the predicted percent of COD removal at the optimized level of variables was close to one (D = 0.991).

Synergetic Degradation of Zidovudine Wastewater by Ultrasonic and Iron-Carbon Micro-Electrolysis

2011 ◽  
Vol 347-353 ◽  
pp. 1949-1952 ◽  
Author(s):  
Liang Li ◽  
Bing Zhe Xu ◽  
Chang Yu Lin ◽  
Xiao Min Hu
Keyword(s):  
Reaction Time ◽  
Degradation Rate ◽  
Removal Rate ◽  
Cod Removal ◽  
Mass Ratio ◽  
Initial Ph ◽  
Cod Removal Rate

Zidovudine wastewater is difficult to biodegradation due to high COD and toxicity. The synergetic treatment of Zidovudine wastewater by Ultrasonic and iron-carbon micro-electrolysis technology was studied. The influence of initial pH, reaction time, mass ratio of iron and carbon and mass ratio of iron and water on degradation rate of COD was researched. The result showed that the COD removal rate was only about 54.3% and the degradation speed is very slow when iron-carbon micro-electrolysis treated Zidovudine wastewater　separately. However, when ultrasonic synergy micro-electrolysis to treat Zidovudine wastewater, the COD removal rate could was up to 85% and the reaction time was also decreased. Moreover, the BOD5 / COD rose from 0.15 to 0.35, which meant the wastewater became easily biodegradable.

scholarly journals Combined Electrocoagulation and Chemical Coagulation in Treating Brewery Wastewater

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 726 ◽  
Author(s):  
Kimberly Swain ◽  
Bassim Abbassi ◽  
Chris Kinsley
Keyword(s):  
Energy Consumption ◽  
Nutrient Removal ◽  
Operating Cost ◽  
Research Work ◽  
Oxygen Demand ◽  
High Strength ◽  
Brewery Wastewater ◽  
Chemical Coagulation ◽  
Electrode Consumption ◽  
Initial Ph

Significant over-strength discharge fees are often imposed on breweries for the disposal of high-strength effluent to sanitary sewers. In this research work, the removal performances of electrocoagulation (EC) compared with operating electrocoagulation and chemical coagulation in sequence (EC-CC) or vice-versa (CC-EC) was examined to determine the capability of treatment in reducing the strength of the wastewater. Optimal operating parameters regarding electrolysis time, initial pH, and applied power were determined in conjunction with nutrient removal performance, electrode consumption and energy usage. Combined EC-CC treatment has been demonstrated to be economically feasible for brewery wastewater applications from an energy consumption perspective due to the efficiency of nutrient removal and the reduction of sewer discharge costs. Treatment by EC-CC at 5 W for 20 min using aluminum electrodes resulted in enhanced and consistent removal efficiencies of 26%, 74%, 76%, and 85% for chemical oxygen demand (COD), reactive phosphorous (RP), total phosphorous (TP) and total suspended solids (TSS), respectively. Energy consumption was the main contributor to operating cost. By considering potential recovered over-strength discharge fees (ODF), EC-CC treatment is economically feasible and beneficial in a brewery wastewater application. The results demonstrated the effectiveness of the CC-EC process to remove phosphorous, organics and solids from brewery wastewater at lower power supply, so that the recovered ODF cost for CC-EC at 5 W-EC is 23% higher than at 10 W-EC.

scholarly journals Optimization of electrocoagulation operating parameters for COD removal from olive mill wastewater: application of Box-Behnken design

2019 ◽  
Vol 9 (3) ◽  
pp. 212-221
Author(s):  
Fatima Erraib ◽  
Khalid El Ass
Keyword(s):  
Response Surface ◽  
Chloride Concentration ◽  
Oxygen Demand ◽  
Olive Mill Wastewater ◽  
Operating Conditions ◽  
Cod Removal ◽  
Coefficient Of Determination ◽  
Box Behnken Design ◽  
Initial Ph ◽  
Olive Mill

Box–Behnken response surface design was successfully employed to optimize and study the olive mill wastewater (OMW) treatment by electrocoagulation (EC) process. The influence of four decisive factors were modelled and optimized to increase the removal of chemical oxygen demand (COD). The Box–Behnken design (BBD) results were analyzed and the second-order polynomial model was developed using multiple regression analysis. The model developed from the experimental design was predictive and a good fit with the experimental data with a high coefficient of determination (R2 ) value (more than 0.98). The optimal operating conditions based on Derringer’s desired function methodology are found to be; initial pH of 4.4, a current density of 27.6 mA/cm2 , electrolysis time of 14.1 min, and chloride concentration of 3.2 g/L. Under these conditions, the predicted COD removal efficiency was found to be 67.14% with a desirability value of 0.94. These experimental results were confirmed by validation experiments and proved that Box–Behnken design and response surface methodology could efficiently be applied for modelling of COD removal from OMW.

scholarly journals Modeling and optimizing electro-persulfate processes using Fe and Al electrodes for paper industry wastewater treatment

2020 ◽  
Vol 81 (2) ◽  
pp. 345-357 ◽  
Author(s):  
Gamze Varank ◽  
Senem Yazici Guvenc ◽  
Ahmet Demir ◽  
Nihal Kavan ◽  
Nurten Donmez ◽  
...  
Keyword(s):  
Reaction Time ◽  
Design Method ◽  
Paper Industry ◽  
Oxygen Demand ◽  
Correlation Coefficients ◽  
Cod Removal ◽  
Contaminant Removal ◽  
Optimization Of Process Parameters ◽  
Appropriate Treatment ◽  
Central Composite

Abstract In this study, the treatment of paper industry wastewaters by the electrocoagulation (EC) process with a strong oxidant, persulfate addition, was investigated. Persulfate was activated by dissolution of Fe and Al from electrodes during the process. Central composite design method, being one of the response surface methods, was applied for the optimization of process parameters and the development of a mathematical model for chemical oxygen demand (COD) removal from paper industry wastewaters. The effects of S2O8−2/COD ratio, current, pH, and reaction time, being the variables of process, were assessed on the efficiency of contaminant removal. For COD removal in EC processes in which Fe and Al electrodes were used, the model's correlation coefficients (R2) were determined as 90.14% and 87.46%, respectively. As the result of experimental study actualized under optimum conditions determined by the model in order to obtain maximum contaminant removal, COD removal efficiencies were determined as 63.5% and 72.8% respectively for the Fe electrode (S2O8−2/COD ratio: 1.25, current: 4.14 A, pH: 6, and reaction time: 5 minutes), and the Al electrode (S2O8−2/COD ratio: 0.5, current: 4.25 A, pH: 7.25, and reaction time: 25 minutes). Electro-activated persulfate process is an appropriate treatment alternative for COD removal from paper industry wastewaters.

Aerobic treatment of inhibitory wastewater using a high-pressure bioreactor with membrane separation

2001 ◽  
Vol 43 (11) ◽  
pp. 51-58 ◽  
Author(s):  
P. C. Male ◽  
W. A. Pretoruis
Keyword(s):  
High Pressure ◽  
Membrane Separation ◽  
Removal Rate ◽  
Oxygen Demand ◽  
High Strength ◽  
Cod Removal ◽  
Stable Operating ◽  
Ultra Filtration ◽  
Biomass Loss ◽  
Cod Removal Rate

Wastewater high in phenolic content (948 mg/l) and dissolved solids (5.4 g/l) had to be treated to remove most of the organic material and toxic compounds. A laboratory scale High Pressure (3 bar) Bioreactor (HPB) was developed and operated to treat the wastewater using a ceramic ultra filtration membrane as biomass separator. The performance of the system was compared to a normal activated sludge plant (ASP) using sludge settling for separation. The HPB was more stable than the ASP, which twice became unstable with a resulting biomass loss. Both reactors removed 90% of the chemical oxygen demand (COD) loading, reducing the phenol concentration below 20 mg/l. The maximum COD removal rate of the HPB was 28 kg/m3.d compared to 15 kg/m3.d of the ASP, while the HPB achieved 16-32 times better oxygen transfer than the ASP. It was concluded that the HPB was the preferred treatment system compared to the ASP, when treating high strength inhibitory wastewaters, due to its stable operating performance and high COD removal rate.

scholarly journals Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4436 ◽  
Author(s):  
Zhiyong Yang ◽  
Penglei Wang ◽  
Yagang Zhang ◽  
Xingjie Zan ◽  
Wenjuan Zhu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Chemical Oxygen Demand ◽  
Polyvinyl Chloride ◽  
Ozone Concentration ◽  
Degradation Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Utilization Efficiency ◽  
High Ozone Concentration ◽  
In Series

Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L−1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L−1. However, when the ozone concentration was increased from 60 mg·L−1 to 80 mg·L−1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.

Edible Plant Oil Wastewater Treatment Using Electro-Fenton Technique: Experiment and Correlation

2018 ◽  
Vol 16 (8) ◽  
Author(s):  
Reza Davarnejad ◽  
Seyed Amir Mohajerani
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Interactive Effects ◽  
Molar Ratio ◽  
Plant Oil ◽  
Edible Plant ◽  
High Chemical Oxygen Demand

Abstract The edible plant oil production factories consume high amounts of water and contaminate the water resources. This type of wastewater consists of high chemical oxygen demand (COD) which should properly be treated by an efficient technique. Furthermore, it is containing some chemicals obtained from several sources such as H3PO4 (from hydration section), NaOH (from neutralization section) and citric acid (from nickel removal section). The conventional techniques cannot efficiently treat it which is full of COD. Therefore, the electro-Fenton process as a rapid, compact and efficient one has been encouraged to be applied. For this purpose, 47 experiments were designed and carried out using iron electrodes to evaluate the effects of five significant independent variables such as reaction time (min), pH, current density (mA/cm2), volume ratio of H2O2/wastewater (ml/l) and H2O2/Fe2+ molar ratio on the COD removal. Response surface methodology (RSM) was employed to assess individual and interactive effects of the parameters. The optimum conditions were experimentally obtained at reaction time of 87.33 min, pH of 3.03, current density of 57 mA/cm2, H2O2/wastewater volume ratio of 2.13 ml/l and H2O2/Fe2+ molar ratio of 3.61 for COD removal of 62.94 %.

Photooxidation of 2,4-dichlorophenoxyacetic acid by ferrous oxalate-mediated system

2004 ◽  
Vol 49 (4) ◽  
pp. 117-122 ◽  
Author(s):  
C.Y. Kwan ◽  
W. Chu
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Light ◽  
Reaction Rates ◽  
Dichlorophenoxyacetic Acid ◽  
Ferrous Ions ◽  
Solution Ph ◽  
Ferrous Oxalate ◽  
Radical Production ◽  
Initial Ph ◽  
2,4 Dichlorophenoxyacetic Acid

The photodegradation of a herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) by ferrous oxalate/UV/H2O2 was studied. Ferrous oxalate, the more photoactive and reactive species, was found to react faster with hydrogen peroxide for hydroxyl radical production than ferrous ions under UV irradiation. About 2.9 times greater rate enhancement was found with the addition of 0.3 mM oxalate than that of a solution containing 0.1 mM Fe2+ and 1 mM H2O2 in the presence of UV light at 253.7 nm. The kinetics dependence of hydrogen peroxide concentration and initial solution pH were also investigated. A threefold increase in peroxide concentration could accelerate the removal of 2,4-D and nearly complete the reaction in 30 min of illumination. The initial decay rate of 2,4-D treated by ferrous oxalate/UV/H2O2 accelerated from 0.0029 to 0.0034 s-1 and the overall removal of the starting material increased from 78% to 99.9%. The 2,4-D transformation at lower initial pH had higher reaction rates than that at higher pH and different reaction mechanisms were identified. The efficiency of the herbicide decomposition was retarded 2.6 times and 9.6 times as initial pH increased from 2.8 to 5.1 and 9.0, respectively.

Degradation of Ciprofloxacin in Aqueous Solution by the Fenton Process

2012 ◽  
Vol 610-613 ◽  
pp. 352-355 ◽  
Author(s):  
Ji Feng Yang ◽  
Hong Hui Chen
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Oxidation Process ◽  
Ph Value ◽  
Fenton Process ◽  
Ferrous Ions ◽  
Reaction Conditions ◽  
Initial Ph ◽  
Optimum Reaction ◽  
Ciprofloxacin Removal

The present study provides results describing the degradation performance of ciprofloxacin antibiotic via Fenton treatment. The effect of reaction conditions including the initial pH value, and dosages of ferrous ions and hydrogen peroxide on ciprofloxacin and COD removal was investigated. Ciprofloxacin removal efficiency of more than 90% was achieved under optimum reaction conditions of pH value of 2, dosages of 0.75 mmol/L of ferrous ion, and 2.0 mmol/L of hydrogen peroxide after 10min. However, the change of COD in aqueous solution was not obvious and further study about intermediate products during oxidation process should be carried out in the future.

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