scholarly journals Advanced treatment of petrochemical secondary effluent by Fenton: performance and organics removal characteristics

2017 ◽  
Vol 75 (6) ◽  
pp. 1431-1439 ◽  
Author(s):  
Min Xu ◽  
Changyong Wu ◽  
Yuexi Zhou
Keyword(s):  
Oxygen Demand ◽  
Cod Removal ◽  
Advanced Treatment ◽  
Secondary Effluent ◽  
Fenton Process ◽  
Direct Oxidation ◽  
Initial Ph ◽  
And Migration ◽  
Chemical Sludge

The Fenton process was used to treat petrochemical secondary effluent. The effects of initial pH, H2O2, and FeSO4·7H2O dosages on chemical oxygen demand (COD) removal, the dissolved organic matter (DOM) removal and the transformation and migration of typical organic matters during the treatment process were investigated. The results showed that the optimum conditions were initial pH of 3.0, H2O2 (30%) dosage of 0.4 mL/L, and FeSO4·7H2O dosage of 1.0 g/L. The highest COD removal efficiency of 61.9% could be achieved for this condition when the average influent COD was 78.5 mg/L. Most of the DOM in the petrochemical wastewater could be removed effectively by Fenton through direct oxidation and coagulation. For example, for trans-1,2-dichlorocyclopentane, results showed that 56.3% of it could be removed by Fenton oxidation, while 13.3% of it could be absorbed by the in situ generated Fenton chemical sludge. The Fenton process is simple and it is suitable for the advanced treatment of petrochemical secondary effluent.

scholarly journals Advanced Treatment of Pesticide-Containing Wastewater Using Fenton Reagent Enhanced by Microwave Electrodeless Ultraviolet

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Gong Cheng ◽  
Jing Lin ◽  
Jian Lu ◽  
Xi Zhao ◽  
Zhengqing Cai ◽  
...  
Keyword(s):  
Organic Contaminants ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Advanced Treatment ◽  
Order Kinetic ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Fenton Reagent ◽  
Doc Concentration ◽  
Initial Ph

The photo-Fenton reaction is a promising method to treat organic contaminants in water. In this paper, a Fenton reagent enhanced by microwave electrodeless ultraviolet (MWEUV/Fenton) method was proposed for advanced treatment of nonbiodegradable organic substance in pesticide-containing biotreated wastewater. MWEUV lamp was found to be more effective for chemical oxygen demand (COD) removal than commercial mercury lamps in the Fenton process. The pseudo-first order kinetic model can well describe COD removal from pesticide-containing wastewater by MWEUV/Fenton, and the apparent rate constant (k) was 0.0125 min−1. The optimal conditions for MWEUV/Fenton process were determined as initial pH of 5, Fe2+dosage of 0.8 mmol/L, and H2O2dosage of 100 mmol/L. Under the optimal conditions, the reaction exhibited high mineralization degrees of organics, where COD and dissolved organic carbon (DOC) concentration decreased from 183.2 mg/L to 36.9 mg/L and 43.5 mg/L to 27.8 mg/L, respectively. Three main pesticides in the wastewater, as Dimethoate, Triazophos, and Malathion, were completely removed by the MWEUV/Fenton process within 120 min. The high degree of pesticides decomposition and mineralization was proved by the detected inorganic anions.

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.

scholarly journals Combined Application of UV Photolysis and Ozonation with Biological Aerating Filter in Tertiary Wastewater Treatment

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Zhaoqian Jing ◽  
Shiwei Cao
Keyword(s):  
Molecular Weight ◽  
Wastewater Treatment ◽  
Organic Pollutants ◽  
Wastewater Treatment Plants ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Secondary Effluent ◽  
Uv Photolysis ◽  
Combined Application

To enhance the biodegradability of residual organic pollutants in secondary effluent of wastewater treatment plants, UV photolysis and ozonation were used in combination as pretreatment before a biological aerating filter (BAF). The results indicated that UV photolysis could not remove much COD (chemical oxygen demand), and the performance of ozonation was better than the former. With UV photolysis combined with ozonation (UV/O3), COD removal was much higher than the sum of that with UV photolysis and ozonation alone, which indicated that UV photolysis could efficiently promote COD removal during ozonation. This pretreatment also improved molecular weight distribution (MWD) and biodegradability greatly. Proportion of organic compounds with molecular weight (MW) <3 kDalton was increased from 51.9% to 85.9%. COD removal rates with BAF and O3/BAF were only about 25% and 38%, respectively. When UV/O3oxidation was combined with BAF, the average COD removal rate reached above 61%, which was about 2.5 times of that with BAF alone. With influent COD ranging from 65 to 84 mg/L, the effluent COD was stably in the scope of 23–31 mg/L. The combination of UV/O3oxidation with BAF was quite efficient in organic pollutants removal for tertiary wastewater treatment.

Electrochemical removal of carbamazepine in water with Ti/PbO2 cylindrical mesh anode

2015 ◽  
Vol 73 (5) ◽  
pp. 1155-1165 ◽  
Author(s):  
J. D. García-Espinoza ◽  
P. Gortáres-Moroyoqui ◽  
M. T. Orta-Ledesma ◽  
P. Drogui ◽  
P. Mijaylova-Nacheva
Keyword(s):  
Supporting Electrolyte ◽  
Oxygen Demand ◽  
Electrochemical Reactor ◽  
Operating Conditions ◽  
Current Intensity ◽  
Oxygen Flux ◽  
Order Kinetic ◽  
Electrolysis Time ◽  
Direct Oxidation

Carbamazepine (CBZ) is one of the most frequently detected organic compounds in the aquatic environment. Due to its bio-persistence and toxicity for humans and the environment its removal has become an important issue. The performance of the electrochemical oxidation process and in situ production of reactive oxygen species (ROS), such as O3 and H2O2, for CBZ removal have been studied using Ti/PbO2 cylindrical mesh anode in the presence of Na2SO4 as supporting electrolyte in a batch electrochemical reactor. In this integrated process, direct oxidation at anode and indirect oxidation by in situ electrogenerated ROS can occur simultaneously. The effect of several factors such as electrolysis time, current intensity, initial pH and oxygen flux was investigated by means of an experimental design methodology, using a 24 factorial matrix. CBZ removal of 83.93% was obtained and the most influential parameters turned out to be electrolysis time, current intensity and oxygen flux. Later, the optimal experimental values for CBZ degradation were obtained by means of a central composite design. The best operating conditions, analyzed by Design Expert® software, are the following: 110 min of electrolysis at 3.0 A, pH = 7.05 and 2.8 L O2/min. Under these optimal conditions, the model prediction (82.44%) fits very well with the experimental response (83.90 ± 0.8%). Furthermore, chemical oxygen demand decrease was quantified. Our results illustrated significant removal efficiency for the CBZ in optimized condition with second order kinetic reaction.

scholarly journals Ferrioxalate-induced solar photo-Fenton treatment of natural rubber latex wastewaters

2015 ◽  
Vol 50 (4) ◽  
pp. 349-358
Author(s):  
Lekshmi Ashok ◽  
S. Adishkumar ◽  
J. Rajesh Banu ◽  
Ick Tae Yeom
Keyword(s):  
Oxalic Acid ◽  
Natural Rubber ◽  
Irradiation Time ◽  
Plug Flow ◽  
Natural Rubber Latex ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Solar Irradiation ◽  
Fenton Process ◽  
Rubber Latex

This study evaluated a ferrioxalate-induced solar photo-Fenton process for natural rubber latex wastewater treatment. The reaction was carried out in a laboratory-scale solar photo-Fenton plug flow baffle reactor. An optimization study was performed using a central composite experimental design including the following variables: pH, initial concentrations of H2O2, Fe2+, and oxalic acid. The photocatalytic degradation efficiency was determined by the analysis of chemical oxygen demand (COD) removal. Under the optimum conditions of pH = 4, Fe2+ = 1.3 g/L, oxalic acid = 2.25 g/L, H2O2 = 82.5 g/L, and solar irradiation time of 6 hours, the COD removal efficiency was 99%. Treatment of latex wastewater by ferrioxalate-induced solar photo-Fenton process increased biodegradability ratio from 0.36 to 0.7 in 2 hours. The overall cost of ferrioxalate-induced solar photo-Fenton oxidation for the treatment of 5 m3 of latex wastewater per day was estimated to be US$85/m3.

scholarly journals Optimization of the Photochemical Degradation of Textile Dye Industrial Wastewaters

2017 ◽  
Vol 33 (1) ◽  
pp. 10 ◽  
Author(s):  
T.H. Dang ◽  
T.P. Mai ◽  
M.T. Truong ◽  
L.T Dao ◽  
T.A.N Nguyen
Keyword(s):  
Design Methodology ◽  
Oxygen Demand ◽  
Textile Dye ◽  
Photochemical Degradation ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Industrial Wastewaters ◽  
Independent Variables ◽  
Initial Ph ◽  
Experimental Design Methodology

In this study, the photochemical degradation via photo-Fenton process was carried out to degrade dyes in textile industrial wastewaters. Experimental design methodology was also applied for optimizing effects of factors which influencethe effective treatment such as ferric dose, hydroperoxide dosage, initial pH, reaction time and initial chemical oxygen demand (COD). Two independent variables namely colour and COD removal efficiencieswere used to evaluate the treatment yield. Under the optimal conditions, ca. 99%  and ca. 88%, colour, and COD were removed, respectively.

scholarly journals Glucose Addition Enhanced the Advanced Treatment of Coking Wastewater

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3365
Author(s):  
Na Li ◽  
Yu Xia ◽  
Xuwen He ◽  
Weijia Li ◽  
Lianhua Yuan ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Oxygen Demand ◽  
Advanced Treatment ◽  
Secondary Effluent ◽  
Coking Wastewater ◽  
Glucose Addition ◽  
Refractory Organic Matter ◽  
Recalcitrant Compounds ◽  
Polycyclic Aromatic ◽  
Removal Efficiencies

Biological processes have high removal efficiencies and low operational costs, but the secondary effluent of coking wastewater (CWW), even at a low concentration, is difficult for microorganisms to degrade directly. In this study, glucose was used as a carbon source and co-metabolic substrate for microbial acclimation in order to enhance the advanced treatment of coking wastewater (CWW). The removal performance of the pollutants, especially recalcitrant compounds, was studied and the changes in the microbial community structure after activated sludge acclimation were analyzed. The effect of glucose addition on the secondary biochemical effluent of coking wastewater (SBECW) treatment by the acclimated sludge was further studied by a comparison between the performance of two parallel reactors seeded with the acclimated sludge. Our results showed that the concentrations of chemical oxygen demand (COD), total organic carbon (TOC), and UV absorption at 254 nm (UV254) of the wastewater decreased in the acclimation process. Refractory organic matter, such as polycyclic aromatic hydrocarbons and nitrogen-containing heterocyclics, in the SBECW was effectively degraded by the acclimated sludge. High-throughput sequencing revealed that microbes with a strong ability to degrade recalcitrant compounds were enriched after acclimation, such as Thauera (8.91%), Pseudomonas (3.35%), and Blastocatella (10.76%). Seeded with the acclimated sludge, the reactor with the glucose addition showed higher COD removal efficiencies than the control system without glucose addition (p < 0.05). Collectively, glucose addition enhanced the advanced treatment of coking wastewater (CWW).

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.

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.

Sign in / Sign up

Export Citation Format

Share Document