scholarly journals Study on COD removal mechanism and reaction kinetics of oilfield wastewater

2017 ◽  
Vol 76 (10) ◽  
pp. 2655-2663 ◽  
Author(s):  
Xian-Qing Yin ◽  
Bo Jing ◽  
Wen-Juan Chen ◽  
Jian Zhang ◽  
Qian Liu ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Kinetic Equations ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Reaction Rate Constant ◽  
Cod Removal ◽  
Removal Mechanism ◽  
Experimental Conditions ◽  
Treated Sewage

Abstract The chemical oxygen demand (COD) removal mechanism and reaction kinetics were mainly studied in the treatment of oilfield oily sewage containing polymer by three-dimensional electrode reactor. The results proved that the residual active oxides O3, H2O2, •OH and active chlorine in the system of electrochemical reaction could be effectively detected, and the COD removal mechanism was co-oxidation of active oxides; Under these experimental conditions: the electrolysis current of 6 A, surface/volume ratio of 6/25(cm2·L−1), the reaction time of 50 min, the CODcr of treated sewage was no more than 50 mg·L−1; the removal reaction of COD conformed to apparent second-order reaction kinetic model, the correlation coefficient R2 was 0.9728, and the apparent reaction rate constant was k = 3.58 × 10−4 (L·min−1·mg−1·m−2). To reach the goal, the CODcr was no more than 50 mg·L−1 in treated sewage, and the theory minimum processing time was 45.73 min. The verification of experimental results was consistent with kinetic equations.

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).

Combined technology for clomazone herbicide wastewater treatment: three-dimensional packed-bed electrochemical oxidation and biological contact degradation

2013 ◽  
Vol 68 (1) ◽  
pp. 257-260 ◽  
Author(s):  
Yujie Feng ◽  
Junfeng Liu ◽  
Limin Zhu ◽  
Jinzhi Wei
Keyword(s):  
Electrochemical Oxidation ◽  
Organic Contaminants ◽  
Removal Rate ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Cell Voltage ◽  
Packed Bed ◽  
Cod Removal ◽  
Cod Removal Rate ◽  
Oxidation Reactor

The clomazone herbicide wastewater was treated using a combined technology composed of electrochemical catalytic oxidation and biological contact degradation. A new type of electrochemical reactor was fabricated and a Ti/SnO2 electrode was chosen as the anode in electrochemical-oxidation reactor and stainless steel as the cathode. Ceramic rings loaded with SnO2 were used as three-dimensional electrodes forming a packed bed. The operation parameters that might influence the degradation of organic contaminants in the clomazone wastewater were optimized. When the cell voltage was set at 30 V and the volume of particle electrodes was designed as two-thirds of the volume of the total reactor bed, the chemical oxygen demand (COD) removal rate could reach 82% after 120 min electrolysis, and the ratio of biochemical oxygen demand (BOD)/COD of wastewater increased from 0.12 to 0.38. After 12 h degradation with biological contact oxidation, the total COD removal rate of the combined technology reached 95%, and effluent COD was below 120 mg/L. The results demonstrated that this electrocatalytic oxidation method can be used as a pretreatment for refractory organic wastewater before biological treatment.

Enhanced degradation of paracetamol by UV-C supported photo-Fenton process over Fenton oxidation

2011 ◽  
Vol 64 (12) ◽  
pp. 2433-2438 ◽  
Author(s):  
B. Manu ◽  
S. Mahamood
Keyword(s):  
Oxygen Demand ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Fenton Process ◽  
Objective Functions ◽  
Optimum Conditions ◽  
Experimental Conditions ◽  
Paracetamol Concentration ◽  
Fenton Oxidation Process ◽  
Uv C

For the treatment of paracetamol in water, the UV-C Fenton oxidation process and classic Fenton oxidation have been found to be the most effective. Paracetamol reduction and chemical oxygen demand (COD) removal are measured as the objective functions to be maximized. The experimental conditions of the degradation of paracetamol are optimized by the Fenton process. Influent pH 3, initial H2O2 dosage 60 mg/L, [H2O2]/[Fe2+] ratio 60 : 1 are the optimum conditions observed for 20 mg/L initial paracetamol concentration. At the optimum conditions, for 20 mg/L of initial paracetamol concentration, 82% paracetamol reduction and 68% COD removal by Fenton oxidation, and 91% paracetamol reduction and 82% COD removal by UV-C Fenton process are observed in a 120 min reaction time. By HPLC analysis, 100% removal of paracetamol is observed at the above optimum conditions for the Fenton process in 240 min and for the UV-C photo-Fenton process in 120 min. The methods are effective and they may be used in the paracetamol industry.

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 %.

Effect of iron nitrate modification on elimination of organic matter from landfill leachate by sludge-based activated carbon

2021 ◽  
pp. 0734242X2110099
Author(s):  
Fan Zeng ◽  
Xiaofeng Liao ◽  
Jiawei Lu ◽  
Danping Pan ◽  
Qili Qiu ◽  
...  
Keyword(s):  
Organic Matter ◽  
Landfill Leachate ◽  
Photoelectron Spectroscopy ◽  
Adsorption Process ◽  
Activated Carbons ◽  
Three Dimensional ◽  
Oxygen Demand ◽  
Ferric Nitrate ◽  
Experimental Conditions ◽  
Valence States

Sludge-based activated carbons (SACs) prepared from sewage sludge and corn straw, were modified by ferric nitrate, and the unmodified SAC and modified SAC were used as the adsorbing agent to treat the landfill leachate, the elimination capacity for chemical oxygen demand (COD) and organic matter in leachate were studied. Based on this, the physicochemical properties of SACs and the components changes in leachate were analyzed and characterized by X-ray photoelectron spectroscopy and three-dimensional fluorescence spectroscopy. The results showed that under optimal experimental conditions, the elimination capacities of SAC372 for COD, biological oxygen demand over 5 days, and NH4+–N in the leachate were 81.58%, 54.73%, and 69.08%, respectively; while the adsorption capacities of modified SAC for these three substances were 86.25%, 63.51%, and 79.15%, respectively. The ferric nitrate modification improved the ability of SAC to eliminate COD and organic matter from leachate slightly, and made the adsorption occurred easily. The adsorption process of unmodified SAC was dominated by multi-layer adsorption, while the adsorption process of modified SAC was dominated by monolayer adsorption. The mass fraction of Fe (2p) in modified SAC remarkably increased, from 0.70% to 26.01%, organic functional groups certain phase of Fe oxides with different valence states were generated in SAC, which provided a substrate for iron–carbon micro electrolysis. After adsorbed by unmodified SAC and modified SAC adsorption, the total fluorescence intensity of in the leachate increased by 17.01% and 116.84%, respectively. Both two SACs could decompose the humic acid-like substances into aromatic protein organic compounds, and modified SAC could further decompose the soluble microbial byproduct-like substances.

Kinetic degradation of guar gum in oilfield wastewater by photo-Fenton process

2016 ◽  
Vol 75 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Shunwu Wang ◽  
Ziwang Li ◽  
Qinglong Yu
Keyword(s):  
Guar Gum ◽  
Oxidative Degradation ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Fenton Process ◽  
Experimental Conditions ◽  
Initial Concentration ◽  
Initial Ph ◽  
Main Component ◽  
The Cost

Guar gum is considered as a main component of oilfield wastewater. This work is intended to optimize the experimental conditions (H2O2 dosage, Fe2+ dosage, initial concentration of organics, initial pH and temperature) for the maximum oxidative degradation of guar gum by Fenton's reagent. The kinetics of guar gum removal were evaluated by means of the chemical oxygen demand (COD) and the absorbance measurements. The batch experiment results showed that the optimum conditions were: H2O2 dosage, 10,000 mg/L; Fe2+dosage, 2,000 mg/L; initial concentration of organics, 413 mg/L; pH, 3 and temperature, 35 °C, under which the COD removal could reach 61.07% and fairly good stability could be obtained. Under the optimum experimental conditions, using UV irradiation to treat the wastewater, the photo-Fenton systems can successfully eliminate COD from guar gum solution. The COD removal always obeyed a pseudo-first-order kinetics and the degradation rate (kapp) was increased by 25.7% in the photo-Fenton process compared to the Fenton process. The photo-Fenton system needed less time and consequently less quantity of H2O2 to obtain the same results as the Fenton process. The photo-Fenton process needs a dose of H2O2 20.46% lower than that used in the Fenton process to remove 79.54% of COD. The cost of the photo/Fenton process amounted to RMB9.43/m3, which was lower than that of the classic Fenton process alone (RMB10.58/m3) and the overall water quality of the final effluent could meet the class Ι national wastewater discharge standard for the petrochemical industry of China.

Pretreatment of Lead 2, 4, 6-trinitroresorcinol Wastewater by Fe-C Internal Electrolysis Process

2014 ◽  
Vol 955-959 ◽  
pp. 1955-1961 ◽  
Author(s):  
Li Heng Liu ◽  
Yan Lin ◽  
Qiang He
Keyword(s):  
Reaction Time ◽  
Orthogonal Experiment ◽  
Volume Ratio ◽  
Degradation Process ◽  
Reaction Rate Constant ◽  
Cod Removal ◽  
Process Conditions ◽  
Order Kinetic ◽  
Electrolysis Process ◽  
Internal Electrolysis

In this study, Fe/C internal electrolysis was used to pretreat the wastewater of lead 2, 4, 6-trinitroresorcinate (LTNR) production. The influences of pH, acids, reaction time and Fe/C volume ratio on COD removal were investigated. The optimum condition of iron-carbon electrolysis was determined by orthogonal experiment. And the reaction kinetics of COD removal and mechanism of contaminant removal were preliminary explored. The results showed that wastewater pH adjusted by sulfuric acid was more economical and better for COD removal. The effect of pH is the greatest. Two processes programs (pH3, Fe/C volume ratio 1.0, reaction time 24hr; pH3, Fe/C volume ratio 1.2, reaction time 18hr) are advised in project. Under the two process conditions, COD removal rates are 73.78% and 72.42%, respectively. The COD removal could be well described by pseudo-second-order kinetic model, and the reaction rate constant is 2.804×10-4 L/(mg·hr). Within the range of 0-24hr, film diffusion is the rate controlling step of the electrolysis process. The degradation process of trinitroresorcinate may be as follow: trinitroresorcinate→nitroaniline phenol or phenol aniline →nitrobenzene quinone or benzoquinone and ammonia→biodegradable or inorganics and nitrate.

scholarly journals Study on kinetic parameter in real yarn dyed wastewater treatment using electrocoagulation-ozonation process

2017 ◽  
Vol 12 (3) ◽  
pp. 690-697 ◽  
Author(s):  
Lieke Riadi ◽  
Ali Altway ◽  
Sasmita Mirifica Vania ◽  
Andy Widyasayogo
Keyword(s):  
Experimental Data ◽  
Wastewater Treatment ◽  
Kinetic Parameter ◽  
Ozone Concentration ◽  
Reaction Rate ◽  
Oxygen Demand ◽  
Reaction Rate Constant ◽  
Agitation Speed ◽  
Cod Removal ◽  
Ozonation Process

Treatment of real yarn dyed wastewater using hybrid electrocoagulation (EC)-ozonation process has been carried out to solve the non biodegradable wastewater. The work aimed to treat the real yarn dyed wastewater under different ozone concentration and agitation speed and to estimate the kinetic parameter of ozonation. The effect of ozone concentration, agitation speed were studied to give the best performance of color and chemical oxygen demand (COD) removal. The result indicated 38.12% of COD removal and 92.53% of color removal using EC with Al/Al electrodes for 10 minutes. The effluent was pumped to ozonation process for further COD removal. The result showed that 1 mg/L ozon was needed to destroy 4.73 mg/L COD. At ozonation process, the COD removal was 87.4% using 5.8% mol ozone at 400 rpm for 60 minutes. The kinetic parameter was estimated based on the experimental data. The reaction rate constant was 173.5 cm3/(g sec).

scholarly journals Electro-photocatalytic degradation of amoxicillin using calcium titanate

2018 ◽  
Vol 16 (1) ◽  
pp. 949-955 ◽  
Author(s):  
Lvshan Zhou ◽  
Xiaogang Guo ◽  
Chuan Lai ◽  
Wei Wang
Keyword(s):  
Photocatalytic Degradation ◽  
Reaction Rate ◽  
Irradiation Time ◽  
Oxygen Demand ◽  
Reaction Rate Constant ◽  
Calcium Titanate ◽  
Experimental Conditions ◽  
Exponential Factor ◽  
First Order ◽  
First Order Kinetics

AbstractThe electro-photocatalytic degradation of amoxicillin in aqueous solution was investigated using single factor test by the potassium permanganate method for measuring the values of chemical oxygen demand (CODMn). Batch experiments were carried out successfully under different conditions, including initial amoxicillin concentration, calcium titanate dosage, pH, UV irradiation time, electrolyte and temperature. The experimental results show that there is a great difference between electro-photocatalytic and photocatalitic degradation. The maximum electro-photocatalytic degradation efficiency can increase to 79% under the experimental conditions of 200 mL amoxicillin solution (100 mg L-1) with 0.5 g calcium titanate by pH=3 for 120 min irradiation and 0.058 g sodium chloride as electrolyte at 318.5K. In addition, the reaction rate constant of 0.00848~0.01349 min-1, activation energy of 9.8934 kJ mol-1 and the pre-exponential factor of 0.5728 were obtained based on kinetics studies, indicating that the electro-photocatalytic reaction approximately followed the first-order kinetics model.

DECOLOURIZATION AND COD REMOVAL OF WASEWATER FROM ETHANOL PRODUCTION PROCESS FROM MOLASSES BY COAGULANTION USING INORGANIC ALUM

2010 ◽  
Vol 13 (3) ◽  
pp. 92-102
Author(s):  
Trung Duc Le
Keyword(s):  
Ethanol Production ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Treatment Processes ◽  
Physico Chemical ◽  
Biological Methods ◽  
Treatment Step ◽  
Main Material

The industrial production of ethanol by fermentation using molasses as main material that generates large quantity of wastewater. This wastewater contains high levels of colour and chemical oxygen demand (COD), that may causes serious environmental pollution. Most available treatment processes in Vietnam rely on biological methods, which often fail to treat waste water up to discharge standard. As always, it was reported that quality of treated wastewater could not meet Vietnameses discharge standard. So, it is necessary to improve the treatment efficiency of whole technological process and therefore, supplemental physico-chemical treatment step before biodegradation stage should be the appropriate choice. This study was carried out to assess the effect of coagulation process on decolourization and COD removal in molasses-based ethanol production wastewater using inorganic coaglutant under laboratory conditions. The experimental results showed that the reductions of COD and colour with the utilization of Al2(SO4)3 at pH 9.5 were 83% and 70%, respectively. Mixture FeSO4 – Al2(SO4)3 at pH 8.5 reduced 82% of colour and 70% of COD. With the addition of Polyacrylamide (PAM), the reduction efficiencies of colour, COD and turbidity by FeSO4 – Al2(SO4)3 were 87%, 73.1% and 94.1% correspondingly. It was indicated that PAM significantly reduced the turbidity of wastewater, however it virtually did not increase the efficiencies of colour and COD reduction. Furthermore, the coagulation processes using PAM usually produces a mount of sludge which is hard to be deposited.

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