scholarly journals Treatment of oilfield wastewater by combined process of micro-electrolysis, Fenton oxidation and coagulation

2017 ◽  
Vol 76 (12) ◽  
pp. 3278-3288 ◽  
Author(s):  
Zhenchao Zhang
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Treatment Process ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Oily Wastewater ◽  
Optimum Conditions ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Optimized Conditions

Abstract In this study, a combined process was developed that included micro-electrolysis, Fenton oxidation and coagulation to treat oilfield fracturing wastewater. Micro-electrolysis and Fenton oxidation were applied to reduce chemical oxygen demand (COD) organic load and to enhance organic components gradability, respectively. Orthogonal experiment were employed to investigate the influence factors of micro-electrolysis and Fenton oxidation on COD removal efficiency. For micro-electrolysis, the optimum conditions were: pH, 3; iron-carbon dosage, 50 mg/L; mass ratio of iron-carbon, 2:3; reaction time, 60 min. For Fenton oxidation, a total reaction time of 90 min, a H2O2 dosage of 12 mg/L, with a H2O2/Fe2+ mole ratio of 30, pH of 3 were selected to achieve optimum oxidation. The optimum conditions in coagulation process: pH, cationic polyacrylamide dosage, mixing speed and time is 4.3, 2 mg/L, 150 rpm and 30 s, respectively. In the continuous treatment process under optimized conditions, the COD of oily wastewater fell 56.95%, 46.23%, 30.67%, respectively, from last stage and the total COD removal efficiency reached 83.94% (from 4,314 to 693 mg/L). In the overall treatment process under optimized conditions, the COD of oily wastewater was reduced from 4,314 to 637 mg/L, and the COD removal efficiency reached 85.23%. The contribution of each stage is 68.45% (micro-electrolysis), 24.07% (Fenton oxidation), 7.48% (coagulation), respectively. Micro-electrolysis is the uppermost influencing process on COD removal. Compared with the COD removal efficiency of three processes on raw wastewater under optimized conditions: the COD removal efficiency of single micro-electrolysis, single Fenton oxidation, single coagulation is 58.34%, 44.88% and 39.72%, respectively. Experiments proved the effect of combined process is marvelous and the overall water quality of the final effluent could meet the class III national wastewater discharge standard of petrochemical industry of China (GB8978-1996).

Study on the Advanced Treatment of Printing and Dyeing Wastewater by Fenton Oxidation

2014 ◽  
Vol 1010-1012 ◽  
pp. 805-808
Author(s):  
Xiu Wen Wu ◽  
Ping Ma ◽  
Hui Xia Lan ◽  
Heng Zhang ◽  
Shan Hong Lan
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Treatment Effect ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Advanced Treatment ◽  
Dyeing Wastewater ◽  
Printing And Dyeing Wastewater ◽  
Cod Removal Efficiency

The influence of H2O2、addition of Fe2+、pH、reaction time and temperature to advanced treatment effect of printing and dyeing wastewater with Fenton oxidation was studied. The results showed that when the addition of H2O2(the concentration was 30%) was 3mL/L,the addition of FeSO4·7H2O was 1.6g/L,pH was 4,the temperature was about 30°C,reacting time was 35min,the COD removal efficiency achieved above 55%,COD of effluent was below 45mg/L.

Textile Wastewater Treatment Using Combined Process of Biological Wriggle Bed and Ozone Biological Aerated Filter

2012 ◽  
Vol 441 ◽  
pp. 589-592
Author(s):  
Zhi Min Fu ◽  
Yu Gao Zhang ◽  
Xiao Jun Wang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Textile Wastewater ◽  
Cod Removal ◽  
Biological Aerated Filter ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Aerated Filter ◽  
Textile Wastewater Treatment

A combined process of biological wriggle bed and ozone biological aerated filter was utilized to treat textile wastewater. Results showed that COD removal efficiency was almost 90.4%. The average effluent COD was 85.87 mg/L. The effluent colority was 64-32 times. This study indicated that the combined process is potentially useful for treating textile wastewater.

scholarly journals Application of response surface methodology to optimize the COD removal efficiency of an EGSB reactor treating poultry slaughterhouse wastewater

2019 ◽  
Vol 14 (3) ◽  
pp. 507-514 ◽  
Author(s):  
Y. Williams ◽  
M. Basitere ◽  
S. K. O. Ntwampe ◽  
M. Ngongang ◽  
M. Njoya ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Removal Efficiency ◽  
Treatment Process ◽  
High Strength ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Wastewater Treatment Process ◽  
Slaughterhouse Wastewater ◽  
Cod Removal Efficiency

Abstract The poultry slaughterhouse industry consumes a large volume of potable water for bird processing and equipment cleaning, which culminates in the generation of high strength poultry slaughterhouse wastewater (PSW). The wastewater contains high concentrations of organic matter, suspended solids, nitrogen and nutrients. Most poultry slaughterhouses in South Africa (SA) discharge their wastewater into the municipal sewer system after primary treatment. Due to its high strength, PSW does not meet SA's industrial discharge standards. Discharge of untreated PSW to the environment raises environmental health concerns due to pollution of local rivers and fresh water sources, leading to odour generation and the spread of diseases. Thus, the development of a suitable wastewater treatment process for safe PSW discharge to the environment is a necessity. In this study, a biological PSW treatment process using an Expanded Granular Sludge Bed (EGSB) was evaluated. Response surface methodology coupled with central composite design was used to optimize the performance of the EGSB reactor. The dependant variable used for optimization was chemical oxygen demand (COD) removal as a function of two independent variables, hydraulic retention time (HRT) and organic loading rate (OLR). The interactions between HRT, OLR and COD removal were analysed, and a two factorial (2FI) regression was determined as suitable for COD removal modelling. The optimum COD removal of 93% was achieved at an OLR of 2 g-COD/L/d and HRT of 4.8 days. The model correlation coefficient (R2) of 0.980 indicates that it is a good fit and is suitable for predicting the EGSB's COD removal efficiency.

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%.

Treatment of Mid-Stage Pulping Effluent Using the Combined Process of Microelectrolysis and Fenton Oxidation-Coagulation

2013 ◽  
Vol 295-298 ◽  
pp. 2001-2010
Author(s):  
Shan Hong Lan ◽  
Xiu Wen Wu ◽  
Yue Ting Wang
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Fenton Oxidation ◽  
Treatment Efficiency ◽  
Combined System ◽  
Removal Rates ◽  
Combined Process ◽  
First Order ◽  
Carbon Mass ◽  
Final Effluent

Mid-stage Pulping Wastewater was pretreated in a combined system of microelectrolysis and Fenton oxidation-coagulation . When the aeration was 6L/min, the ratio of iron-carbon mass was 4/1, the addition of iron was 1500mg/L, pH was 4, and reaction time was 30min, the removal rates of COD and chrominance reached 65% and 60% respectively and the concentration of generated Fe2+ reached 157mg/L. Fe2+ generated by micro-electrolysis process was used for the following Fenton oxidation. When the conditions was without additional Fe2+, the addition of H2O2 (concentration is 30%) was 3mL/L, pH was 4, and the reaction time was 15min, the removal rates of COD and chrominance both reached over 80% and the concentration of generated Fe2+ reached 217mg/L. Fe3+ generated by Fenton oxidation was used for following studies of flocculation. The treatment efficiency of three kinds of flocculants PAM, PAC and silicate was compared. The results showed that the effect of PAM was best, the treatment efficiency reached the best when its additon was 0.15mL/L as pH was 7. the removal efficiency of COD reached 41% and the chrominance removal efficiency reached 75%, the final effluent chrominance was 4 and the COD concentration was 45mg/L which was lower than 60mg/L, that met with the first order of effluent standard.

Dioctyl Phthalate Esters Wastewater Treatment by Fenton Reagent / Fly Ash Combined Process

2013 ◽  
Vol 777 ◽  
pp. 122-126
Author(s):  
Li Ping Wang ◽  
Xin Ying Li ◽  
Xiang Mei Li
Keyword(s):  
Fly Ash ◽  
Removal Efficiency ◽  
Phthalate Esters ◽  
Dioctyl Phthalate ◽  
Cod Removal ◽  
Fenton Reagent ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Simulated Wastewater ◽  
Better Than

Used Fenton reagent and fly ash combined process to treat dioctyl phthalate (DOP) simulated wastewater. Influences of pH, concentration of H2O2, Fe2+ concentration, fly ash dosage and other factors effect of COD were studied. The results showed that, under the synergies of the fly ash, Fenton reagent on the COD removal efficiency was better than Fenton reagent used alone. When the pH was 5, H2O2 concentration was 1.2 g/L, Fe2+ concentration was 1.0g/L, fly ash dosage was 4 g, and COD removal efficiency reached 83.21%.

Treatment of Sodium Formate Wastewater by Fenton Oxidation Process

2012 ◽  
Vol 573-574 ◽  
pp. 627-630
Author(s):  
Zhi Gang Chen ◽  
Rui Xue Zhang ◽  
Bo Zhang ◽  
An Ping Wei
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Oxidation Process ◽  
Ph Value ◽  
Sodium Formate ◽  
Cod Removal ◽  
Fenton Oxidation ◽  
Fenton Process ◽  
Initial Ph ◽  
Fenton Oxidation Process

In this study, in order to reduce the sodium formate concentration thereby reducing toxicity, the treatment of this wastewater by Fenton process was investigated. The effects of initial PH value, reaction time, concentration of FeSO4• 7H2O, and H2O2 dosage on the removal efficiency of COD were studied respectively. The experiment results show that when using Fenton oxidization pretreatment process, with pH 2.0, FeSO4•7H2O concentration 4000mg/L, H2O2(30 % ) portion 4ml/L, and reaction time 20min, COD removal efficiency was more than 50%, oxidization efficiency was good.

scholarly journals Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Cod Removal ◽  
Septic Tank ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Cod Removal Efficiency

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

scholarly journals Combined treatment of hydroxypropyl guar gum in oilfield fracturing wastewater by coagulation and the UV/H2O2/ferrioxalate complexes process

2017 ◽  
Vol 77 (3) ◽  
pp. 565-575 ◽  
Author(s):  
Zhenchao Zhang
Keyword(s):  
Removal Efficiency ◽  
Guar Gum ◽  
Combined Treatment ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Spectra Analysis ◽  
Hydroxypropyl Guar ◽  
Coagulation Process ◽  
Cod Removal Efficiency ◽  
Hydroxypropyl Guar Gum

Abstract Hydroxypropyl guar gum is considered to be a main component of oilfield fracturing wastewater (OFW). This work is intended to optimize the experimental conditions for the maximum oxidative degradation of hydroxypropyl guar gum by the coagulation and UV/H2O2/ferrioxalate complexes process. Optimal reaction conditions were proposed based on the chemical oxygen demand (COD) removal efficiency and UV_vis spectra analysis. The overall removal efficiency of COD reached 83.8% for a dilution ratio of raw wastewater of 1:2, pH of 4 and FeCl3 loading of 1,000 mg/L in the coagulation process; the dosage of H2O2 (30%,v/v) was 0.6% (v/v) and added in three steps, the n(H2O2)/n(Fe2+) was 2:1, n(Fe2+)/n(C2O42−) was 3:1 and pH was 4 in the UV/H2O2/ferrioxalate complexes process; pH was adjusted to 8.5–9 by NaOH and then cationic polyacrylamide (CPAM) of 2 mg/L was added in the neutralization and flocculation process. The decrease in COD during the coagulation process reduced the required H2O2 dosage and improved efficiency in the subsequent UV/H2O2/ferrioxalate complexes process. Furthermore, COD removal efficiency significantly increased by more than 13.4% with the introduction of oxalate compared with UV/Fenton. The UV_vis spectra analysis results indicated that the coagulation and UV/H2O2/ferrioxalate complexes process could efficiently remove the hydroxypropyl guar gum dissolved in OFW. An optimal combination of these parameters produced treated wastewater that met the GB8978-1996 Integrated Wastewater Discharge Standard level III emission standard.

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.

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