Research on Coal Chemical Wastewater Treatment by Nano-TiO2 Powder Photocatalytic Oxidation Process

2012 ◽  
Vol 550-553 ◽  
pp. 2232-2236 ◽  
Author(s):  
Pei Yao Xu ◽  
Xiu Jie Chu ◽  
Yan Qing Li ◽  
Fan Zhang
Keyword(s):  
Photocatalytic Oxidation ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Cod Removal ◽  
Illumination Time ◽  
Photocatalytic Effect ◽  
Uv Lamp ◽  
Cod Removal Rate ◽  
Raw Wastewater

Abstract. With TiO2 as photocatalyst, hydrogen peroxide(H2O2) as oxidant, treated the coal chemical wastewater under the condition of 30W UV lamp irradiation. Discussed the effects of those factors—pH, dosage of TiO2 powder, dosage of FeCl3, dosage of H2O2 and illumination time etc. on Chemical Oxygen Demand(COD) removal rate of wastewater. The results have shown that: when taking the pH of raw water, TiO2 0.2g per 100ml wastewater, FeCl3 0.01g per 100ml wastewater, H2O2 1.2 ml per 100ml wastewater, 5h illumination time, quiet place 3h, acquired the best photocatalytic effect. After treated under the optimum technological conditions, the COD removal rate reached 70.09%; the removal rate of Biological Oxygen Demand(BOD5), ammonia nitrogen, cyanide and color reached respectively to 58.60%、39.99%, 72.41% and 90%. After repeated 10 times, all the active of TiO2 was almost lost. With the regeneration treatment by high-temperature cauterization, the regenerated catalyst was added into the raw wastewater. Then under the optimum technological conditions, after illuminated 7h, the COD removal rate of wastewater recovered to 49.47%.

Research for Treating Avermectin Wastewater with UASB Technique

2011 ◽  
Vol 356-360 ◽  
pp. 1281-1284
Author(s):  
Yan Hong Chang ◽  
Hui Tao Feng ◽  
Hui Luo ◽  
San Jian Ma
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Removal Rate ◽  
Nitrogen Concentration ◽  
Ammonia Nitrogen ◽  
Cod Removal ◽  
Stable Phase ◽  
Volume Load ◽  
Cod Removal Rate

The avermectin wastewater was treated with UASB technique. The paper was focused mainly on the removal rate of COD and the change of ammonia nitrogen of influent and effluent wastewater in the first running stage. At the stable phase of anaerobic operation, the removal rate of COD could be stabilized at 85% when the influent volume load was 9.21 kg/(m3•d), and the effluent COD was about 1400 mg/L. As for ammonia nitrogen concentration of influent and effluent wastewater, in the first 50 days, the former was larger than the latter, after then, it was opposite. In the condition of same volume load but different hydraulic retention time (COD concentration of influent being different), COD removal rate kept almost the same. In the second running stage, the influent COD volume load reached 9.21 kg/(m3•d) at the 16th day, with the COD removal rate being around 87%.

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.

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.

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.

Anaerobic Treatment of Cheese Dairy Wastewater Using the SNC Bioreactor

1993 ◽  
Vol 28 (3) ◽  
pp. 597-620 ◽  
Author(s):  
Catherine N. Mulligan ◽  
Bechara F. Safi ◽  
Jacques Meunier ◽  
Jean Chebib
Keyword(s):  
Retention Time ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Cod Removal ◽  
Dairy Wastewater ◽  
Organic Load ◽  
Whey Permeate ◽  
Cod Removal Rate

Abstract The SNC multiplate reactor (1,200 L) has been developed and tested to determine chemical oxygen demand (COD) removal, nutrient requirement, and gas production from the anaerobic treatment of effluents generated at the Agropur (Notre Dame-du-Bon-Conseil, Quebec) and Nutrinor cheese dairies (Chambord, Quebec). At the Agropur plant, wastewater (3,000 mg/L COD) was treated the best at a retention time of 12 h. Using this retention time, effluents containing whey with organic loads of 10.2 to 41.6 kg COD/m3/day could be treated at a 84% COD removal rate. When the reactor was subjected to shock by increasing the organic load suddenly from 8.9 to 31 kg COD/m3/day, the total COD removal decreased to 72% and then returned to 86% after 7 days. Hydrology tests indicated that the reactor functions as a series of completely mixed stirred tanks. At Nutrinor, using a 12-h retention time and diluted whey permeate (20,000 mg/L COD), total COD removal was 86% and gas production was 12.0 m3/m3/day for a loading of 36.5 kg COD/m3/day. Nutrient supplementation was not required. For experiments performed with different proportions of wastewater (2,000 mg/L COD) to whey permeate (70,000 mg/L COD) results of 89% total and 93% soluble COD removal with a gas production of 11 m3/m3/day for a loading of 25 kg COD/m3/day were obtained. Retention times were varied from 18 to 60 h to correspond to initial CODs of 20,000 to 70,000 mg/L. In conclusion, this reactor functions in a superior manner to other published anaerobic treatment systems.

Electrochemical Pretreatment of Wastewater from DDNP Production Using BDD Thin Film Electrode

2011 ◽  
Vol 255-260 ◽  
pp. 2962-2966
Author(s):  
Rong Gui Fan ◽  
Chun E Li ◽  
Yong Xin Bai ◽  
Da Qing Huang ◽  
Liao Wei Fang ◽  
...  
Keyword(s):  
Thin Film ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Cell Voltage ◽  
Cod Removal ◽  
Interelectrode Distance ◽  
Film Electrode ◽  
Boron Doped Diamond ◽  
Thin Film Electrode ◽  
Cod Removal Rate

The electrochemical oxidation of wastewater from DDNP production was investigated using a boron-doped diamond (BDD) thin film electrode. The effects of operating factors such as cell voltage, interelectrode distance and additive NaCl have been studied. This study showed that the chemical oxygen demand (COD) reduction is most influenced by the applied cell voltage. Higher current densities resulting from higher cell voltages increase the formation of oxidative reagents resulting in an increased COD removal rate. The maximum COD removal was 57% after 210 min, with an energy consumption of 14.90 KWh·kg-1 COD when cell voltage was 12V, interelectrode distance was 3cm and additive NaCl concentration was 1g·L-1. The use of BDD thin film electrode for the treatment of DDNP production wastewater appears commercially feasible.

Photocatalytic Oxidation Degradation Behavior on Fracturing Wastewater in Oilfield

2011 ◽  
Vol 396-398 ◽  
pp. 1918-1922 ◽  
Author(s):  
Li Ping Wan ◽  
Ying Feng Meng ◽  
Gao Li ◽  
Hua Zhou
Keyword(s):  
Photocatalytic Oxidation ◽  
Ph Value ◽  
Removal Rate ◽  
Oil Field ◽  
Cod Removal ◽  
Composite Catalyst ◽  
Application Time ◽  
Secondary Pollution ◽  
Cod Removal Rate ◽  
Temperature Activation

Due to great variety additives and disposal difficulty, chemical method, biochemical method and solidification are adopted to treat fracturing wastewater in oil field. These processes easily bring about shortcomings, including high cost and secondary pollution. Studied on the treatment of fracturing wastewater of 4# well in Sichuan Oilfield by modified bentonite loading TiO2-Ag2O composite catalyst, COD removal rate is determined for different condition of pH value of solution, adding content of TiO2, inflating volume and light application time. The optimal condition is obtained as follows: pH value of solution is 3, adding content of TiO2 is 0.4-0.5%, inflating volume is 15L/min and light application time is 3h. Under this condition, COD removal rate of fracturing wastewater is 58.1%. The composite catalyst performance is stable and without secondary pollution. It is reusable by high temperature activation, so it can reduce wastewater treatment cost, and should be widely applied.

scholarly journals Catalytic wet peroxide oxidation degradation of magenta wastewater and preparation of FeOCl/montmorillonite

2021 ◽  
Author(s):  
Tiancheng Hun ◽  
Binxia Zhao ◽  
Tingting Zhu ◽  
Linxue Liu ◽  
Zhiliang Li ◽  
...  
Keyword(s):  
Removal Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Impregnation Method ◽  
Dye Wastewater ◽  
Peroxide Oxidation ◽  
Melting Method ◽  
Wet Peroxide Oxidation ◽  
Catalytic Wet Peroxide Oxidation ◽  
Cod Removal Rate

Abstract The iron oxychloride/pillared montmorillonite (FeOCl/MMT) catalyst was prepared by wet impregnation method and solid melting method. Various characterization techniques were used to analyze the microscopic morphology and structure of a series of catalysts. Moreover, the catalysts were used to treat magenta simulated dye wastewater through catalytic wet peroxide oxidation (CWPO) degradation. The magenta removal rate and chemical oxygen demand (COD) removal rate of the magenta simulated dye wastewater were used to evaluate the catalytic performance of the catalyst, and the optimal catalyst preparation conditions were selected. The results showed that the solid melting method was more favorable to the preparation of the catalyst, and the COD removal rate of wastewater can reach 70.8% when the FeOCl load was 3%. Moreover, 96.2% of the magenta in the solution has been removed. The COD removal rate of the magenta wastewater decreased by only 12.4% after the catalyst was repeatedly used six times, indicating that the catalyst has good activity and stability. The Fermi equation can simulate the reaction process of the catalyst treating magenta wastewater at high temperature.

scholarly journals Investigation of the effect of magnetic field on the chemical oxygen demand removal of wastewater

2021 ◽  
Author(s):  
Anup Jagadeesh
Keyword(s):  
Magnetic Field ◽  
Chemical Oxygen Demand ◽  
Biological Treatment ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Flow Rates ◽  
Wastewater Quality ◽  
Cod Removal Rate ◽  
The Magnetic Field

This study investigated the effect of magnetic field on the biological treatment of wastewater at varied liquid volumetric flow rates. Wastewater quality is measured by Chemical Oxygen Demand (COD) which quantifies the amount of oxygen required to chemically oxidize organic compounds present in the water. The results obtained from the present study show that at the flow rate of 6.7 x 10⁻⁵ m³s⁻¹ there was a significant effect on the COD removal. At lower flow rates the magnetic field had more time to act on the microorganisms which in-turn increased the COD removal rate. However at flow rates 3.3 x 10⁻⁴ to 1.2 x 10⁻⁴ m³s⁻¹ the effect of the applied magnetic field on the COD removal decreased slightly.

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