scholarly journals An integrated mathematical model for chemical oxygen demand (COD) removal in moving bed biofilm reactors (MBBR) including predation and hydrolysis

2016 ◽  
Vol 98 ◽  
pp. 84-97 ◽  
Author(s):  
Marta Revilla ◽  
Berta Galán ◽  
Javier R. Viguri
Keyword(s):  
Mathematical Model ◽  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Moving Bed ◽  
Biofilm Reactors

Treatment of synthetic kraft evaporator condensate using thermophilic and mesophilic membrane aerated biofilm reactors

2010 ◽  
Vol 61 (7) ◽  
pp. 1749-1756 ◽  
Author(s):  
B. Q. Liao ◽  
M. R. Zheng ◽  
L. Ratana-Rueangsri
Keyword(s):  
Comparative Study ◽  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Biofilm Reactors ◽  
Cod Removal Efficiency

A comparative study on the treatment of synthetic kraft evaporator condensate was conducted using thermophilic (55°C) and mesophilic (30°C) membrane aerated biofilm reactors (MABRs) and sequencing batch reactors (SBRs) for 8 months. Under tested conditions, a chemical oxygen demand (COD) removal efficiency of 80–95% was achieved with both thermophilic and mesophilic MABRs and SBRs. The COD removal efficiency of thermophilic MABR (80–90%) was slightly lower than that of the mesophilic MABR (85–95%) and the thermophilic SBR (90–95%). A significant amount (13–37%) of COD was stripped by conventional aeration in the SBRs, while stripping in MABRs was negligible. Simultaneous COD removal and denitrification were observed in the mesophilic MABR, while the thermophilic MABR contributed mainly for COD removal. Nitrification was not significant in both the thermophilic and mesophilic MABRs. The results suggest that treatment of kraft evaporator condensate is feasible with the use of both thermophilic and mesophilic MABRs in terms of COD removal with the advantages of negligible stripping.

scholarly journals Organic matter removal from oil-water emulsions by electrocoagulation: 2 - mathematical model

2014 ◽  
Vol 67 (1) ◽  
pp. 67-72
Author(s):  
Rodolfo Maia Rangel ◽  
Roberto José de Carvalho ◽  
Maurício Leonardo Torem
Keyword(s):  
Mathematical Model ◽  
Organic Matter ◽  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Organic Matter Removal ◽  
Synthetic Oil ◽  
Electrocoagulation Process ◽  
Oil Water

A mathematical model of the organic matter (chemical oxygen demand - COD) removal from synthetic oil-water emulsions by the electrocoagulation process was developed to evaluate the COD abatement. The model comprises the three fundaments of electrocoagulation: electrochemistry, coagulation and flotation. By comparing the experimental and calculated values of COD, it was found that the model was able to adequately predict the concentrations of organic matter (COD) present in the emulsions and satisfactorily describe the electrocoagulation process.

scholarly journals Optimization and Modelling of Chemical Oxygen Demand Removal by ANAMMOX Process Using Response Surface Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Jalilzadeh ◽  
Ramin Nabizadeh ◽  
Alireza Mesdaghinia ◽  
Aliakbar Azimi ◽  
Simin Nasseri ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Response Surface ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Ammonium Concentration ◽  
Ammonium Oxidation ◽  
Optimum Conditions ◽  
Surface Method ◽  
Anammox Process ◽  
Modelling And Optimization

A systematic model for chemical oxygen demand (COD) removal using the ANAMMOX (Anaerobic AMMonium OXidation) process was provided based on an experimental design. At first, the experimental data was collected from a combined biological aerobic/anaerobic reactor. For modelling and optimization of COD removal, the main parameters were considered, such as COD loading, ammonium, pH, and temperature. From the models, the optimum conditions were determined as COD 97.5 mg/L, ammonium concentration equal to 28.75 mg-N/L, pH 7.72, and temperature 31.3°C. Finally, the analysis of the optimum conditions, performed by the response surface method, predicted COD removal efficiency of 81.07% at the optimum condition.

scholarly journals Innovative Effluent Capture and Evacuation Device that Increases COD Removal Efficiency in Subsurface Flow Wetlands

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 418 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Verónica Lazcano-Castro ◽  
Gisela Silva-Vasquez ◽  
Mauricio Llanos-Baeza ◽  
Ignacio Fuentes-Ortega
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Cod Removal ◽  
Discharge Device ◽  
The Impact ◽  
Real Scale ◽  
Conventional Device

The objective of this work is to evaluate the impact of innovative modifications made to conventional effluent capture and discharge devices used in subsurface flow wetlands (SSFW). The main modifications that have been developed extend the influence of the capture and discharge device in such a way that the SSFW width and height are fully covered. This improved innovative device was applied and evaluated in two subsurface flow wetlands, one on a pilot scale and one on a real scale. To evaluate the impact of the innovative device with respect to the conventional one in the operational functioning of subsurface flow wetlands, the elimination of chemical oxygen demand (COD) was measured and compared. The results show that for the innovative device, the COD removal was 10% higher than for the conventional device, confirming the validity and effectiveness of the modifications implemented in the effluent capture and discharge devices used in SSFW.

scholarly journals Treatment of Bio-Treated Coking Wastewater by Catalytic Ozonation with Semi-Batch and Continuous Flow Reactors

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2532
Author(s):  
Can He ◽  
Jianbing Wang ◽  
Heng Xu ◽  
Xiangyu Ji ◽  
Weiyi Wang ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Continuous Flow ◽  
Oxygen Demand ◽  
Catalytic Ozonation ◽  
Cod Removal ◽  
Utilization Efficiency ◽  
Coking Wastewater ◽  
Ozone Absorption ◽  
Flow Reactors ◽  
Continuous Flow Reactors

In this work, the treatment of bio-treated coking wastewater (BCW) by catalytic ozonation was conducted in semi-batch and continuous flow reactors. The kinetics of chemical oxygen demand (COD) removal were analyzed using BCWs from five coking plants. An integral reactor with catalytic ozonation stacked by ozone absorption (IR) was developed, and its efficiency was studied. The catalyst of MnxCe1-xO2/γ-Al2O3 was efficient in the catalytic ozonation process for the treatment of various BCWs. The chemical oxygen demand (COD) removal efficiencies after 120 min reaction were 64–74%. The overall apparent reaction rate constants were 0.0101–0.0117 min−1, which has no obvious relationship with the initial COD of BCW and pre-treatment biological process. The IR demonstrated the highest efficiency due to the enhancement of mass transfer and the utilization efficiency of ozone. Bypass internal circulation can further improve the reactor efficiency. The optimal results were obtained with the ozone absorption section accounting for 19% of the valid water depth in the reactor and 250% of circulation flow ratio. The long-term and full-scale application of the novel reactor in a continuous mode indicated stable removal of COD and polycyclic aromatic hydrocarbons (PAHs). The results showed that the system of IR is a promising reactor type for tertiary treatment of coking wastewater by catalytic ozonation.

Coupling of anodic oxidation and adsorption by granular activated carbon for chemical oxygen demand removal from 4,4′-diaminostilbene-2,2′-disulfonic acid wastewater

2010 ◽  
Vol 62 (11) ◽  
pp. 2669-2677 ◽  
Author(s):  
Lizhang Wang ◽  
Yuemin Zhao
Keyword(s):  
Activated Carbon ◽  
Chemical Oxygen Demand ◽  
Residence Time ◽  
Applied Voltage ◽  
Oxygen Demand ◽  
Granular Activated Carbon ◽  
Cod Removal ◽  
Disulfonic Acid ◽  
High Concentration ◽  
Solution Ph

Experiments were performed to reduce chemical oxygen demand (COD) from 4,4′-diaminostilbene-2,2′-disulfonic (DSD) acid manufacturing wastewater using electrochemical oxidation coupled with adsorption by granular activated carbon. The COD removal is affected by the residence time and applied voltage. When the residence time is increased, lower value of COD effluent could be obtained, however, the average current efficiency (ACE) decreased rapidly, and so does the applied voltage. In addition, aeration could effectively enhance COD removal efficiency and protect anodes from corrosion. Furthermore, the acidic condition is beneficial to the rapid decrease of COD and the values of pH effluent are independent of the initial solution pH. The optimization conditions obtained from these experiments are applied voltage of 4.8 V, residence time of 180 min and air–liquid ratio of 4.2 with the COD effluent of about 690 mg L−1. In these cases, the ACE and energy consumption are 388% and 4.144 kW h kg−1 COD, respectively. These perfect results from the experiments illustrate that the combined process is a considerable alternative for the treatment of industrial wastewater containing high concentration of organic pollutants and salinity.

Organic carbon and nitrogen removal in moving-bed biofilm reactors

1997 ◽  
Vol 35 (6) ◽  
pp. 91-99 ◽  
Author(s):  
G. Pastorelli ◽  
G. Andreottola ◽  
R. Canziani ◽  
C. Darriulat ◽  
E. de Fraja Frangipane ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Potassium Nitrate ◽  
Biofilm Reactor ◽  
Cod Removal ◽  
Removal Rates ◽  
Moving Bed ◽  
Biofilm Reactors ◽  
Batch Tests ◽  
Nitrate Uptake Rate ◽  
Reported Data

Pilot moving-bed biofilm reactors (MBBRs), fed on primary settled wastewater, were used in order to study organic carbon removal and nitrification. Nitrate uptake rate (NUR) tests were performed by feeding sodium acetate and potassium nitrate to a bench-scale moving-bed batch biofilm reactor. In both experiments the same polyethylene biofilm carriers were used. Both particulate and filtered COD removal rates appear to be proportional to the corresponding loading rates. Particulate COD removal is the net effect of adsorption onto and release from the biofilm surface. Filtered COD removal is the sum of the influent filtered COD removal and the removal of hydrolysed colloidal COD. Filtered COD removal rates could not be evaluated with a kinetic expression because back-diffusion from biofilm is not always negligible. Nitrification tests, performed at oxygen limiting conditions, show that the reaction rate was nearly first order with respect to dissolved oxygen due to liquid film diffusion. Denitrification batch tests showed denitrification rates very close to other reported data. Since the process proved reliable and easy-to-operate, it is suitable for application to small WWTPs, either in designing new plants or in upgrading existing overloaded activated sludge systems.

scholarly journals Improved Ozonation Efficiency for Polymerization Mother Liquid from Polyvinyl Chloride Production Using Tandem Reactors

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4436 ◽  
Author(s):  
Zhiyong Yang ◽  
Penglei Wang ◽  
Yagang Zhang ◽  
Xingjie Zan ◽  
Wenjuan Zhu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Chemical Oxygen Demand ◽  
Polyvinyl Chloride ◽  
Ozone Concentration ◽  
Degradation Rate ◽  
Oxygen Demand ◽  
Cod Removal ◽  
Utilization Efficiency ◽  
High Ozone Concentration ◽  
In Series

Polymerization mother liquid (PML) is one of the main sources of wastewater in the chlor-alkali industry. The effective degradation of the PML produced in PVC polymerization using three or five ozone reactors in tandem was designed with a focus on improving the ozonation efficiency. The ozonation efficiency of the tandem reactors for the degradation of PML, along with the effect of ozone concentration, the number of reactors utilized in series, and the reaction time on the chemical oxygen demand (COD) removal were investigated in detail. The results showed that the COD removal increased as the ozone concentration was increased from 10.6 to 60 mg·L−1, achieving 66.4% COD removal at ozone concentration of 80.6 mg·L−1. However, when the ozone concentration was increased from 60 mg·L−1 to 80 mg·L−1, the COD removal only increased very little. The COD decreased with increasing ozone concentration. During the initial degradation period, the degradation rate was the highest at both low and high ozone concentrations. The degradation rate decreased with reaction time. The rate at a low ozone concentration decreased more significantly than at high ozone concentration. Although high ozone concentration is desirable for COD removal and degradation rate, the utilization efficiency of ozone decreased with increasing ozone concentration. The ozone utilization efficiency of the five-reactor device was three times higher than that of three tandem reactors, demonstrating that ozonation utilization efficiency can be improved by increasing the number of tandem reactors. Ozonation in tandem reactors is a promising approach for PML treatment.

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