Kinetics of Fecal Coliform Removal in Constructed Wetlands

1999 ◽  
Vol 40 (3) ◽  
pp. 109-116 ◽  
Author(s):  
N. R. Khatiwada ◽  
C. Polprasert
Keyword(s):  
Kinetic Model ◽  
Constructed Wetlands ◽  
Fecal Coliform ◽  
Removal Rate ◽  
Free Water ◽  
Pilot Scale ◽  
Performance Data ◽  
Rate Coefficients ◽  
Model Parameters ◽  
Kinetics Of

Major mechanisms influencing the removal of fecal microorganisms in constructed wetlands treating sewage in tropical regions include the effects of temperature, solar radiation, sedimentation, adsorption and filtration. This study aims to develop a model describing the kinetics of fecal coliform removal in free-water-surface (FWS) constructed wetlands. Separate model equations were proposed for removal rate coefficients for each of the major removal mechanisms. The model parameters were assessed from both literature and the performance data of laboratory-scale FWS constructed wetland units planted with cattails (Typha angustifolia). The model parameters and the kinetic model were validated with experimental data of two pilot-scale constructed wetlands. Statistical analyses of the calculated and observed performance data of the pilot-scale units revealed good correlation and were without significant practical difference, suggesting the kinetic model was feasible.

A model for organic matter removal in free water surface constructed wetlands

1998 ◽  
Vol 38 (1) ◽  
pp. 369-377 ◽  
Author(s):  
C. Polprasert ◽  
N. R. Khatiwada ◽  
J. Bhurtel
Keyword(s):  
Organic Matter ◽  
Constructed Wetlands ◽  
Water Surface ◽  
Oxygen Demand ◽  
Free Water ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Cod Removal ◽  
Model Parameters ◽  
Free Water Surface

This study was conducted to determine performance of free water surface (FWS) constructed wetlands located in the tropics in the removal of organic matter and to assess the importance of biofilm bacteria in the overall kinetics of organic matter (or chemical oxygen demand, COD) removal. Because constructed wetlands normally contain both biofilm and suspended bacteria, a kinetic model incorporating the activities of these two bacteria groups, dispersion number and hydraulic retention time, was employed. The model parameters essential for the calculation of COD removal in FWS constructed wetlands were determined from the experiments and some from the literature. The model was found satisfactory in predicting COD removal efficiencies in a pilot-scale FWS constructed wetland unit treating a domestic wastewater.

Experimental and Kinetic Production of Ethanol Using Mucilage Juice Residues from Cocoa Processing

2018 ◽  
Vol 16 (11) ◽  
Author(s):  
Teresa Romero Cortes ◽  
Jaime A. Cuervo-Parra ◽  
Víctor José Robles-Olvera ◽  
Eduardo Rangel Cortes ◽  
Pablo A. López Pérez
Keyword(s):  
Ethanol Yield ◽  
Scale Up ◽  
Pilot Scale ◽  
Product Formation ◽  
Model Parameters ◽  
Pichia Kudriavzevii ◽  
Proposed Model ◽  
Analysis Of Results ◽  
Residual Plots ◽  
Kinetics Of

AbstractEthanol was produced using mucilage juice residues from processed cocoa with Pichia kudriavzevii in batch fermentation. Experimental results showed that maximum ethanol concentration was 13.8 g/L, ethanol yield was 0.50 g-ethanol/g glucose with a productivity of 0.25 g/L h. Likewise, a novel phenomenological model based on the mechanism of multiple parallel coupled reactions was used to describe the kinetics of substrate, enzyme, biomass and product formation. Model parameters were optimized by applying the Levenberg-Marquardt approach. Analysis of results was based on statistical metrics (such as confidence interval), sensitivity and by comparing calculated curves with the experimental data (residual plots). The efficacy of the proposed mathematical model was statistically evaluated using the dimensionless coefficient for efficiency. Results indicated that the proposed model can be applied as a way of augmenting bioethanol production from laboratory scale up to semi-pilot scale.

Biodegradation kinetics of BTE-OX and MTBE by a diesel-grown biomass

2006 ◽  
Vol 53 (11) ◽  
pp. 197-204 ◽  
Author(s):  
K. Acuna-Askar ◽  
M.A. de la Torre-Torres ◽  
M.J. Guerrero-Munoz ◽  
M.T. Garza-Gonzalez ◽  
B. Chavez-Gomez ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Removal Rate ◽  
Biodegradation Kinetics ◽  
Aqueous Samples ◽  
Removal Rates ◽  
Two Phase ◽  
Bacterial Populations ◽  
Substrate Removal ◽  
Benzene Toluene ◽  
Kinetics Of

The biodegradation kinetics of BTE-oX and MTBE, mixed all together in the presence of diesel-grown bioaugmented bacterial populations as high as 885 mg/L VSS, was evaluated. The effect of soil in aqueous samples and the effect of Tergitol NP-10 on substrate biodegradation rates were also evaluated. Biodegradation kinetics was evaluated for 54 h, every 6 h. All BTE-oX chemicals followed a first-order two-phase biodegradation kinetic model, whereas MTBE followed a zero-order removal kinetic model in all samples. BTE-oX removal rates were much higher than those of MTBE in all samples. The presence of soil in aqueous samples retarded BTE-oX and MTBE removal rates. The addition of Tergitol NP-10 to aqueous samples containing soil had a positive effect on substrate removal rate in all samples. Substrate percent removals ranged between 64.8–98.9% for benzene, toluene and ethylbenzene. O-xylene and MTBE percent removals ranged between 18.7–40.8% and 7.2–10.3%, respectively.

scholarly journals Kinetics of nitrogen removal processes in constructed wetlands

2018 ◽  
Vol 26 ◽  
pp. 00001 ◽  
Author(s):  
Magdalena Gajewska ◽  
Katarzyna Skrzypiec
Keyword(s):  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Kinetic Models ◽  
Treatment Wetlands ◽  
Rate Coefficients ◽  
Biological Processes ◽  
Monod Kinetics ◽  
Removal Processes ◽  
Kinetics Of ◽  
Removal Model

The aim of this paper is to present a state-of-the-art review of the kinetics of nitrogen removal in constructed wetlands. Biological processes of nitrogen removal from wastewater can be described using equations and kinetic models. Hence, these kinetic models which have been developed and evaluated allow for predicting the removal of nitrogen in treatment wetlands. One of the most important, first order removal model, which is still applied, was analysed and its rate coefficients and factors were compared. This study also demonstrates the validity of Monod and multiple Monod kinetics, commonly seen today. Finally, a computational example of the reaction kinetics of nitrogen removal was also included in the study.

scholarly journals Effect of the Influent Substrate Concentration on Nitrogen Removal from Summer to Winter in Field Pilot-Scale Multistage Constructed Wetland–Pond Systems for Treating Low-C/N River Water

2021 ◽  
Vol 13 (22) ◽  
pp. 12456
Author(s):  
Tao Wang ◽  
Liping Xiao ◽  
Hongbin Lu ◽  
Shaoyong Lu ◽  
Xiaoliang Zhao ◽  
...  
Keyword(s):  
River Water ◽  
Constructed Wetlands ◽  
Nitrogen Removal ◽  
Constructed Wetland ◽  
Substrate Concentration ◽  
Removal Rate ◽  
Carbon Sources ◽  
River Estuary ◽  
Pilot Scale ◽  
Surface Flow

The quality of micropolluted water is unstable and its substrate concentration fluctuates greatly. The goal is to predict the concentration effect on the treatment of nitrogen in a river with an actual low C/N ratio for the proposed full-scale Xiaoyi River estuary wetland, so that the wetland project can operate stably and perform the water purification function effectively in the long term. Two pilot-scale multistage constructed wetland–pond (MCWP) systems (S1 and S2, respectively) based on actual engineering with the same “front ecological oxidation ponds, two-stage horizontal subsurface flow constructed wetlands and surface flow constructed wetlands (SFCWs) as the core and postsubmerged plant ponds” as the planned process were constructed to investigate the effect of different influent permanganate indexes (CODMn) and total nitrogen (TN) contents on nitrogen removal from micropolluted river water with a fixed C/N ratio from summer to winter in the field. The results indicate that the TN removal rate in the S1 and S2 systems was significant (19.56% and 34.84%, respectively). During the process of treating this micropolluted water with a fixed C/N ratio, the influent of S2 with a higher CODMn concentration was conducive to the removal of TN. The TN removal rate in S2 was significantly affected by the daily highest temperature. There was significant nitrogen removal efficiency in the SFCWs. The C/N ratio was a major determinant influencing the nitrogen removal rate in the SFCWs. The organic matter release phenomenon in SFCWs with high-density planting played an essential role in alleviating the lack of carbon sources in the influent. This research strongly supports the rule that there is seasonal nitrogen removal in the MCWPs under different influent substrate concentrations, which is of guiding significance for practical engineering.

Nitrogen management in reservoir catchments through constructed wetland systems

2005 ◽  
Vol 51 (11) ◽  
pp. 175-181 ◽  
Author(s):  
B. Tunçsiper ◽  
S.Ç. Ayaz ◽  
L. Akça ◽  
A. Samsunlu
Keyword(s):  
Constructed Wetlands ◽  
Plug Flow ◽  
Free Water ◽  
Pilot Scale ◽  
Surface Flow ◽  
Nitrogen Management ◽  
Organic N ◽  
Flow Reactors ◽  
First Order ◽  
Continuous Flow Reactors

In this study, nitrogen removal was investigated in pilot-scale subsurface flow (SSF) and in free water surface flow (FWS) constructed wetlands installed in the campus of TUBITAK-Marmara Research Center, Gebze, near Istanbul, Turkey. The main purposes of this study are to apply constructed wetlands for the protection of water reservoirs and to reuse wastewater. Experiments were carried out at continuous flow reactors. The effects of the type of plants on the removal were investigated by using emergent (Canna, Cyperus, Typhia spp., Phragmites spp., Juncus, Poaceae, Paspalum and Iris.), submerged (Elodea, Egeria) and floating (Pistia, Salvina and Lemna) marsh plants at different conditions. During the study period HLRs were 30, 50, 70, 80 and 120 L m2 d−1 respectively. The average annual NH4-N, NO3-N, organic N and TN treatment efficiencies in SSF and FWS wetlands are 81% and 68%, 37% and 49%, 75% and 68%, 47% and 53%, respectively. Nitrification, denitrification and ammonification rate constant (k20) values in SSF and FWS systems have been found as 0.898 d−1 and 0.541 d−1, 0.488 d−1 and 0.502 d−1, 0.986 d−1 and 0.908 respectively. Two types of the models (first-order plug flow and multiple regression) were tried to estimate the system performances

Kinetic Study of the Dehydrogenation of Isobutane over V-K-O /ZSM5 Catalyst

2013 ◽  
Vol 798-799 ◽  
pp. 174-177 ◽  
Author(s):  
Teng Teng Wu ◽  
Cheng Xue Wang
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Kinetic Model ◽  
Atmospheric Pressure ◽  
Contact Time ◽  
Model Parameters ◽  
Isobutane Dehydrogenation ◽  
Dehydrogenation Reaction ◽  
Reaction Pressure ◽  
Kinetics Of

The reaction kinetics of the dehydrogenation of isobutane over V-K-O /ZSM5 catalyst was investigated. The powerfunction model was established;The isobutane dehydrogenation reaction tests were carried out between 833-863K and reaction pressure to atmospheric pressure by changing the contact time(w/F=0.464-0.532gh/mol) ,through the experimental data the kinetics of model parameters were analyzed.The results show that the power-function kinetic model is reasonable,the apparent activation energy is 177.7492KJ/mol.

Ozone disinfection of primary effluent using a stirred tank reactor

1986 ◽  
Vol 13 (5) ◽  
pp. 510-516 ◽  
Author(s):  
D. L. Caverson ◽  
G. R. Finch ◽  
D. W. Smith
Keyword(s):  
Fecal Coliform ◽  
Pilot Scale ◽  
Stirred Tank ◽  
Linear Least Squares ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Before And After ◽  
Reliable Design ◽  
Ozone Disinfection ◽  
Kinetics Of

A pilot-scale stirred tank reactor was used to evaluate the efficiency of ozone for disinfecting primary effluent. Total and fecal coliform numbers before and after disinfection were evaluated concomitant with several common wastewater characteristics. A disinfection model was built using the method of linear least squares. The model enables the designer to choose the transferred ozone dose to achieve a given number of indicator bacteria in the effluent when the BOD5 is known. The model was found to be useful for the primary effluent studied but should not be used in other applications without pilot plant investigations. Examination of similar models reported in the literature suggests that weak wastewaters (COD < 25 mg/L) may be described by a regression model using COD and transferred ozone as variables but extrapolation to moderate and strong wastewaters, as was done in this study, introduced gross errors. Further research into the fundamental kinetics of ozone disinfection of wastewater is necessary before a reliable design model is available. Key words: ozone, disinfection, primary eflluent, model, coliforms.

scholarly journals Seasonal Applicability of Three Plant Constructed Wetlands for Nutrient Removal in Pilot Scale

2016 ◽  
Author(s):  
Farham Aminsharei ◽  
Seyed Mehdi Borghei ◽  
Reza Arjomandi ◽  
Jafar Nouri ◽  
Alireza Pendashteh
Keyword(s):  
Phragmites Australis ◽  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Seasonal Changes ◽  
Removal Rate ◽  
Pilot Scale ◽  
Seasonal Growth ◽  
Sensitive Species ◽  
Long Time ◽  
The Difference

The main objective of this study was to compare the removal efficiency of nutrients using Lactuca sativa, Medicago sativa and Phragmites australis in subsurface flow constructed wetlands with horizontal flow. In order to test water quality, fabricated reactors designed and the plants cultivated in the soil while their root were inside the wastewater. A long time study carried out from spring till end of autumn (9 months) in order to evaluate the difference in removal rate based on the seasonal changes. The highest removal rate was during summer which followed by spring and autumn. Thus, the effect of plants on the removal efficiency of organic matter (COD, BOD), TSS and nutrient (P and TN) appeared to be dependent on the seasonal growth. Phragmites australis the most sensitive species in order the removal of nutrient from wastewater.

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