Fenton-Like Oxidation of Refractory Chemical Wastewater Using Pyrite

2012 ◽  
Vol 518-523 ◽  
pp. 2518-2525 ◽  
Author(s):  
Yong Feng ◽  
De Li Wu ◽  
Dong Duan ◽  
Ming Ma Lu
Keyword(s):  
Ph Value ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Solution Ph ◽  
Natural Iron ◽  
Fenton Reagents ◽  
Value Range ◽  
Cod Removal Rate ◽  
High Level

Fenton-like reaction technologies are attracting considerable attention due to the high oxidizing ability, especially in the treatment of refractory chemical contaminants. However, some disadvantages in traditional Fenton reagents limited its wide application. In this study, pyrite, a natural iron bearing mineral, was used as a new kind of Fenton-like catalyst in the treatment of textile wastewater. The catalytic activity of pyrite and the parameters influencing the removal of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD5), such as pyrite dosage, H2O2 concentration, pH, and suspended solids (SS) had been systematically examined. Results showed that pyrite exhibited a high catalytic reactivity over a wide pH value range. At the optimal conditions, a COD removal rate of 70% and an increase in the mass ratio of BOD5/COD (B/C) from 0.25 to 0.56 were achieved in the presence of 9.7 mM H2O2 and 10 g/L pyrite at initial solution pH value of 9.0. And what’s more, a rapid decrease in solution pH and a high level of iron were observed when pyrite was added to the wastewater, probably due to the oxidative dissolution of pyrite. Consequently, Apart from the heterogeneous process, it was found that a homogeneous interaction between ferrous iron and H2O2 in a classical Haber-Weiss mechanism was also occurred. The wonderful reactivity of pyrite makes it be used as catalyst for the oxidative technology to treat the original wastewater without the need to pre-adjust the solution pH.

A Study of Fenton’s Oxidation Pretreatment on Dye Wastewater Containing Acetic Acid

2014 ◽  
Vol 1044-1045 ◽  
pp. 215-218
Author(s):  
Xian Huan Qiu ◽  
Hai Yu ◽  
Peng Fei Deng
Keyword(s):  
Acetic Acid ◽  
Processing Time ◽  
Ph Value ◽  
Removal Rate ◽  
Cod Removal ◽  
Dye Wastewater ◽  
Fenton’S Oxidation ◽  
Effects Of Ph ◽  
Cod Removal Rate ◽  
Fenton's Oxidation

In the presence of acetic acid, the effects of pH, processing time, addition of Fe2+ and H2O2 on dye wastewater treatment were studied. Experimental results showed that in the presence of acetic acid, when the pH value was 4, the processing time was 30.0min, addition of ferrous sulfate was 4.8g/L, and addition of hydrogen peroxide was 56mL/L, the treatment effect was the best, COD removal rate reached 51.0%. Further studied of the effect of the presence of acetic acid on Fenton’s oxidation of dye wastewater, the results showed that without of acetic acid, the COD removal rate was higher than that with acetic acid. And the effect of Fenton's reagent on oxidation of dye substances was interfered by the presence of acetic acid.

The Study on Anaerobic Fermentative Biological Hydrogen Production with Organic Wastes

2010 ◽  
Vol 113-116 ◽  
pp. 1476-1480
Author(s):  
Xiao Ye Liu ◽  
Yi Sun ◽  
Jian Yu Yang ◽  
Yong Feng Li
Keyword(s):  
Ph Value ◽  
Biogas Production ◽  
Removal Rate ◽  
Maximum Yield ◽  
Liquid Product ◽  
Oxygen Demand ◽  
H2 Production ◽  
Hydrogen Yield ◽  
Continuous Stirred Tank Reactor ◽  
Brown Sugar

This papre discussed the ability of H2-production and wastewater treatment, a continuous stirred tank reactor (CSTR)using a synthesized substrate with brown sugar wastewater was conducted to investigate the hydrogen yield, fermentation type of biohydrogen production, and the chemical oxygen demand (COD) removal rate, respectively. The results show that when the pH value was 4.0～4.5, OLR was 24.5kg/(m3•d), oxidation-reduction potential was -350～-450mv, temperature was 34.0°C～36.0°C, hydraulic retention time was 6h～8h, the maximum yield of biogas production reached 20L/d and the maximum content of hydrogen is 70%. Detection of the end liquid product, ethanol and acetic acid are main, they are 70% ~90% of the total liquid product, so that is called ethanol-type fermentation.

The pretreatment of acrylonitrile and styrene with the ozonation process

1997 ◽  
Vol 36 (2-3) ◽  
pp. 263-270 ◽  
Author(s):  
Cheng-Nan Chang ◽  
Jih-Gaw Lin ◽  
Allen C. Chao ◽  
Bo-Chuan Cho ◽  
Ruey-Fang Yu
Keyword(s):  
Organic Nitrogen ◽  
Ph Value ◽  
Raw Materials ◽  
Removal Rate ◽  
Acrylonitrile Butadiene Styrene ◽  
Ozone Treatment ◽  
Oxidation Reduction ◽  
Initial Ph ◽  
Cod Removal Rate ◽  
Ozonation Process

Acrylonitrile and styrene are used as the raw materials for manufacturing acrylic fiber, thus they are often found as pollutants in the petrochemical wastewater. This study utilizes ozone to decompose the organic nitrogen contained in acrylonitrile and styrene, and the oxidation process was monitored using on-line measurements of oxidation-reduction potential (ORP) and pH. The efficiency of organic nitrogen decomposition was also estimated based on the COD, organic nitrogen, TOC, ammonia-N, nitrite, and nitrate measurements. Both the initial pH and alkalinity are observed to affect the degradation rate of organic nitrogen. The acrylonitrile sample with the lowest initial pH value (i.e., 4.0) has a shorter t1/2 of 18.9 min and that for samples of the highest initial pH (i.e., 11) was 34 min. The alkalinity of one acrylonitrile sample was boosted by adding 500 mg/l CaCO3, to simulate the field ABS (Acrylonitrile-Butadiene-Styrene) wastewater effluent. It was observed that within a short ozone contact time, the acrylonitrile sample spiked with 500 mg/l CaCO3 had the highest COD decomposition rate of 0.411 min−1, or 1.3 times more than that for samples without addition of CaCO3. Results of the ozonation process can be fitted with a modified Nernst equation for the various pH conditions. Additionally, the ozone treated synthetic ABS sample shows a faster COD removal rate in the subsequent biological process than those samples without ozone treatment.

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.

Research on Waste Materials with Decentralized White Spirit Wastewater Pretreatment by Fe-C Micro-Electrolysis

2014 ◽  
Vol 644-650 ◽  
pp. 5419-5422
Author(s):  
Jin Xiang Fu ◽  
Hong Mei Li ◽  
Peng Fei Yu ◽  
Kai Zhao
Keyword(s):  
Phosphorus Removal ◽  
Ph Value ◽  
Removal Rate ◽  
Temperature Response ◽  
Brewery Wastewater ◽  
Electrochemical Test ◽  
Optimal Processing ◽  
Water Ph ◽  
Cod Removal Rate ◽  
Iron Electrolysis

This research adopts the important iron electrolysis, removal of the wastewater of high COD, SS, phosphorus pretreatment experiment. Discusses the different iron dosing quantity, iron carbon ratio, and pH value, reaction time on the COD and turbidity, the influence of the phosphorus removal effect. Studies show that iron important electrochemical test in brewery wastewater treatment static optimal processing conditions for: water pH value is 4, 5% dosage of iron filings, 60 min temperature response, COD removal rate was 52.31%. When the iron carbon ratio of 2:1, removing effect is good, can reach 54.53%.

scholarly journals Bioaugmentation with Mixed Hydrogen-Producing Acetogen Cultures Enhances Methane Production in Molasses Wastewater Treatment

Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shuo Wang ◽  
Jianzheng Li ◽  
Guochen Zheng ◽  
Guocheng Du ◽  
Ji Li
Keyword(s):  
Wastewater Treatment ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Anaerobic Wastewater Treatment ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Molasses Wastewater ◽  
Cod Removal Rate ◽  
Rate Limiting

Hydrogen-producing acetogens (HPA) have a transitional role in anaerobic wastewater treatment. Thus, bioaugmentation with HPA cultures can enhance the chemical oxygen demand (COD) removal efficiency and CH4yield of anaerobic wastewater treatment. Cultures with high degradation capacities for propionic acid and butyric acid were obtained through continuous subculture in enrichment medium and were designated as Z08 and Z12. Bioaugmentation with Z08 and Z12 increased CH4production by glucose removal to 1.58. Bioaugmentation with Z08 and Z12 increased the COD removal rate in molasses wastewater from 71.60% to 85.84%. The specific H2and CH4yields from COD removal increased by factors of 1.54 and 1.63, respectively. Results show that bioaugmentation with HPA-dominated cultures can improve CH4production from COD removal. Furthermore, hydrogen-producing acetogenesis was identified as the rate-limiting step in anaerobic wastewater treatment.

Study on the Model of Limonite-TiO2 Combined Microspheres Photolysising Phenol in Source Water

2012 ◽  
Vol 518-523 ◽  
pp. 121-124
Author(s):  
Hong Xia Xia ◽  
Qi Hong Zhu
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Ph Value ◽  
Removal Rate ◽  
Source Water ◽  
Quadratic Regression ◽  
Solution Ph ◽  
Experimental Conditions ◽  
Orthogonal Regression ◽  
Single Factor Experiment

This paper investigates the effect of Limonite/TiO2 combined microspheres dosage,solution pH, reaction time,light intensity on the removal rate of phenol in source water.Based on the single factor experiment, the experimental conditions are optimized by quadratic regression orthogonal rotation combination design.The quadratic orthogonal regression model of removal rate of phenol(y) to four factors of Limonite/TiO2 combined microspheres dosage(x1),pH(x2),reaction time (x3)and light intensity (x4) is established as Y=88.64+4.43X1+ 6.69X3+3.75X4-4.79X12-13.20X22-4.21X32-2.69X42+8.06X1X2-6.76X1X3-4.45X1X4.It can conclude from the model that when Limonite/TiO2 combined microspheres dosage is 1.5583g,solution pH value is 4.5095,reaction time is 102.12min,light intensity is 1710.8（x10 lux）,the yield(y) reaches the maximal(95.83%) and consistent with the confirmatory experiment result..

Treatment of synthetic wastewater and hog waste with reduced sludge generation by the multi-environment BioCAST technology

2013 ◽  
Vol 67 (3) ◽  
pp. 587-593 ◽  
Author(s):  
L. Yerushalmi ◽  
M. Alimahmoodi ◽  
C. N. Mulligan
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Synthetic Wastewater ◽  
Nitrogen And Phosphorus ◽  
Treatment Technology ◽  
Minimal Impact ◽  
Biological Sludge ◽  
Removal Efficiencies ◽  
Cod Removal Rate

Simultaneous removal of carbon, nitrogen and phosphorus was examined along with reduced generation of biological sludge during the treatment of synthetic wastewater and hog waste by the BioCAST technology. This new multi-environment wastewater treatment technology contains both suspended and immobilized microorganisms, and benefits from the presence of aerobic, microaerophilic, anoxic and anaerobic conditions for the biological treatment of wastewater. The influent concentrations during the treatment of synthetic wastewater were 1,300–4,000 mg chemical oxygen demand (COD)/L, 42–115 mg total nitrogen (TN)/L, and 19–40 mg total phosphorus (TP)/L. The removal efficiencies reached 98.9, 98.3 and 94.1%, respectively, for carbon, TN and TP during 225 days of operation. The removal efficiencies of carbon and nitrogen showed a minimal dependence on the nitrogen-to-phosphorus (N/P) ratio, while the phosphorus removal efficiency showed a remarkable dependence on this parameter, increasing from 45 to 94.1% upon the increase of N/P ratio from 3 to 4.5. The increase of TN loading rate had a minimal impact on COD removal rate which remained around 1.7 kg/m3 d, while it contributed to increased TP removal efficiency. The treatment of hog waste with influent COD, TN and TP concentrations of 960–2,400, 143–235 and 25–57 mg/L, respectively, produced removal efficiencies up to 89.2, 69.2 and 47.6% for the three contaminants, despite the inhibitory effects of this waste towards biological activity. The treatment system produced low biomass yields with average values of 3.7 and 8.2% during the treatment of synthetic wastewater and hog waste, respectively.

Changes of pH in A2O Process System and its Impact on Nitrogen and Phosphorus Removal

2012 ◽  
Vol 588-589 ◽  
pp. 55-58
Author(s):  
Yong Feng Li ◽  
Jian Yu Yang ◽  
Guo Cai Zhang
Keyword(s):  
Phosphorus Removal ◽  
Ph Value ◽  
Removal Rate ◽  
Phosphorus Release ◽  
Ammonia Nitrogen ◽  
Biological Nutrient Removal ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Process System ◽  
High Level

Simulate sewage were used in an anaerobic-anoxic-aerobic biological nutrient removal system(A2O process), by observing the pHs in different compartments and its reflected changes in nitrogen and phosphorus removal, studied on the effects of different pHs on the removal of pollutants. The experiments indicates that the anaerobic phosphorus release showed the main performance of the decline of pH, denitrification in anoxic zone caused the rise of pH, uptake of phosphate in the aerobic zone mainly caused the continuous rise of pH. There is no evidently changes in COD removal, ammonia nitrogen get the highest removal as the pH value was between 8.0-8.5, when pH was at 6.5-7.5, the TN have the maximum removal rate, TP can keep in a high level when the pH was above 6.0.

scholarly journals Treatment of textile wastewater using a novel electrocoagulation reactor design

2018 ◽  
Vol 20 (3) ◽  
pp. 449-457
Keyword(s):  
Wastewater Treatment ◽  
Rotation Speed ◽  
Removal Rate ◽  
Operating Time ◽  
Oxygen Demand ◽  
Textile Wastewater ◽  
Total Suspended Solid ◽  
Operating Conditions ◽  
Conventional Model ◽  
Textile Wastewater Treatment

<p>This study explored the best-operating conditions for a novel electrocoagulation (EC) reactor with the rotating anode for textile wastewater treatment. The influence of operating parameters like inter-electrode distance (IED), current density (CD), temperature, pH, operating time (RT), and rotation speed on the removal efficiency of the contaminant was studied. A comparative study was done using conventional model with static electrodes in two phases under same textile wastewater The findings revealed that the optimal conditions for textile wastewater treatment were attained at RT = 10 min, CD = 4 mA/cm2, rotation speed = 150 rpm, temperature = 25oC, IED = 1cm, and pH = 4.57. The removal efficiencies of colour, biological oxygen demand (BOD), turbidity, chemical oxygen demand (COD), and total suspended solid (TSS) were 98.50%, 95.55%, 96%, 98% and 97.10% within the first 10 min of the reaction. The results of the experiment reveal that the newly designed reactor incorporated with cathode rings and rotated anode impellers provide a superior treatment efficiency within a short reaction time. The novel EC reactor with a rotating anode significantly enhanced textile wastewater treatment compared to the conventional model. The values of adsorption and passivation resistance validated the pollutants removal rate.</p>

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