scholarly journals Fouling Identification for Nanofiltration Membrane and the Potential Reduction of Pollutants in the Leachate by Using Fe/Al/PAC Coagulation

2021 ◽  
Vol 13 (3) ◽  
pp. 1114
Author(s):  
Chang-wei He ◽  
Hui Wang ◽  
Luo-chun Wang ◽  
Zi-yang Lou ◽  
Li Bai ◽  
...  
Keyword(s):  
Removal Rate ◽  
Three Dimensional ◽  
Engineering Application ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Nanofiltration Membrane ◽  
Leachate Treatment ◽  
Inorganic Matter ◽  
Cod Removal Rate ◽  
Inorganic Precipitation

The reduction in the fouling is an important way to maintain the steady operation for the nanofiltration (NF) process in leachate treatment. The fouling components from the real leachate treatment process were identified using a scanning electron microscope equipped with X-ray microanalysis (SEM-EDS), infrared spectroscopy (FTIR), atomic analysis and three-dimensional fluorescence (EEM) analysis, and the coagulation of Fe/Al/PAC was selected to reduce the potential pollutants in the leachate, to reduce the potential fouling. It was found that organic humic acid and calcium-magnesium precipitates were the main pollutants in NF fouling. The foulant layer was the result of the combination of organic matter, inorganic precipitation, colloids and microorganisms, and the colloids precipitation is more important, and should be removed in advance. PAC was found to be more efficiency to reduce the colloids and the inorganic matter, among the coagulants selection, with the chemical oxygen demand (COD) removal rate of 55.1%. The commercially available coagulant-poly aluminum chloride (PAC) was chosen as a coagulant. The removal rate of leachate reached 55.1%, and the flow rate through the membrane was increased by 35.8% under the optimum condition (pH was 5.0, PAC dosage was 100 mg/L, and the membrane pressure was 0.4 MPa). Through the pilot scale test, the effluent was connected to the microfiltration membrane and then to the nanofiltration membrane and the practical engineering application is feasible.

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.

Performance of a modified RBC system in simulated municipal wastewater treatment

2012 ◽  
Vol 66 (9) ◽  
pp. 2014-2019
Author(s):  
Tang Yun-lu ◽  
Liu Dong-fang ◽  
Meng Xian-rong ◽  
Yu Jie ◽  
Wang Jin ◽  
...  
Keyword(s):  
Rotational Speed ◽  
System Performance ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Engineering Application ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Municipal Wastewater Treatment ◽  
Positive Role ◽  
Cod Removal Rate

A new method based on rotating biological contactor (RBC) was employed for solving the problems of long hydraulic retention times (HRT) low specific surface area and organic loading rates (OLR) in conventional RBCs. The system showed its particular adsorption ability of microorganisms in the biofilm-attaching period. Microbes on the first cage were observed in comparison with the second one. Packing biodisc also had a good shock load tolerance. It was observed that the system performance improved at higher HRTs, while at the increased level of input OLR, the removal performance worsened slightly. The positive role of rotational speed in the treatment of municipal wastewater was more pronounced in the range of 10–12 rpm. Chemical oxygen demand (COD) removal rate achieved 94% under the optimal operating conditions, which were HRT of 1.5 h, rotational speed of 9.9 rpm. The modified RBC system is highly beneficial to engineering application for better system performance and lower energy consumption.

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.

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.

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.

scholarly journals Polishing of Chemical Oxygen Demand (COD) Using Moving Bed Bio-Reactor

2015 ◽  
Vol 773-774 ◽  
pp. 1281-1285
Author(s):  
Jamal Ali Kawan ◽  
Rakmi Abd-Rahman ◽  
Othman bin Jaafar ◽  
Fatihah Suja
Keyword(s):  
Chemical Oxygen Demand ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Research Work ◽  
Real Life ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Biofilm Reactor ◽  
Moving Bed ◽  
Building Engineering

The pilot-scale experiment in moving bed biofilm reactor (MBBR) with a capacity of 433 L was carried out for this study with real life situations, it was decided that the complete research work must be done under as realistic conditions as possible,i.e.with real municipal wastewater, chemical free and with local commercially available products such as carriers for biofilm reactor. The reactor was start-up in 30/9/2013 up to date, Effluent from clarifier of STP used as influence of MBBR for polishing. MBBR is using continues down flow to polish effluent municipal wastewater from a faculty of new building engineering community in UKM to get the water free from main pollutant parameters, for reuse in the irrigation or discharge to the river. Laboratory experiments will conduct with different hydraulic retention time (HRT), filling ratio of plastic (Enviro Multi Media) in the MBBR about 5%. Aerobic reactors used the majority of the decaying organic material. An average removal rate of 41.75%, 32.85%, 24.80% and 35.77% of initial chemical oxygen demand (COD) were achieved under a HRT of 24hr, 12hr, 6hr and 2hr, respectively. The model simulated results showed good agreements with experimental results. The model could be employed in the design of a full-scale MBBR process for simultaneous removal of organic carbon from effluent STP.

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%.

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