Simulation of the Denitrification Process of Waste Water with a Biochemical Systems Model: A Non-Conventional Approach

2014 ◽  
Vol 12 (2) ◽  
pp. 683-693
Author(s):  
Nouceiba Adouani ◽  
Lionel Limousy ◽  
Thomas Lendormi ◽  
Eberhard O. Voit ◽  
Olivier Sire
Keyword(s):  
Waste Water ◽  
Nitrate Reduction ◽  
International Association ◽  
Mass Action ◽  
Experimental Conditions ◽  
Systems Model ◽  
Theoretical Approaches ◽  
Biochemical Systems ◽  
Nitrate And Nitrite ◽  
Denitrification Process

Abstract Matching experimental and theoretical approaches have often been fruitful in the investigation of complex biological processes. Here we develop a novel non-conventional model for the denitrification of waste water. Earlier models of the denitrification process were compiled by the International Association on Water Quality group. The Activated Sludge Models 1–3, which are the most frequently used all over the world, are presently not adapted towards the integration of both nitrous and nitric oxide emissions during the denitrification process. In the present work, a Generalized Mass Action model, based on Biochemical Systems Theory, was designed to simulate the nitrate reduction observed in specific experimental conditions. The model was implemented and analysed with the software package PLAS. Data from a representative experiment were chosen (T=10°C, pH=7, C/N=3, with acetate as carbon source) to simulate greenhouse NO and N2O gas emissions, in order to test hypotheses about the corresponding bacterial metabolic pathways. The results show that the reduction of nitrate and nitrite is kinetically limiting and that nitrate reduction is limited by diffusion and support that distinct microbial subpopulations are involved in the denitrification pathway, which has consequences for NO emissions.

scholarly journals Supported Biofilms on Carbon–Oxide Composites for Nitrate Reduction in Agricultural Waste Water

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2987
Author(s):  
M. Isidora Bautista-Toledo ◽  
Francisco J. Maldonado-Hódar ◽  
Sergio Morales-Torres ◽  
Luisa M. Pastrana-Martínez
Keyword(s):  
Waste Water ◽  
Escherichia Coli ◽  
Physicochemical Properties ◽  
Carbon Material ◽  
Nitrate Reduction ◽  
Agricultural Waste ◽  
Carbon Oxide ◽  
Gaseous Products ◽  
Oxide Composites ◽  
Denitrification Process

Escherichia coli colonies were grown on different supports for the removal of nitrates from water. A carbon material and different commercial metal oxides, such as SiO2, TiO2 and Al2O3, and their corresponding carbon–metal oxide composites were studied. The physicochemical properties were analyzed by different techniques and the results were correlated with their performance in the denitrification process. Developed biofilms effectively adhere to the supports and always reach the complete reduction of nitrates to gaseous products. Nevertheless, faster processes occur when the biofilm is supported on mesoporous and non-acid materials (carbon and silica).

Pre-Precipitation Facilitates Nitrogen Removal without Tank Expansion

1990 ◽  
Vol 22 (7-8) ◽  
pp. 85-92 ◽  
Author(s):  
Ingemar Karlsson ◽  
Gunnar Smith
Keyword(s):  
Waste Water ◽  
Organic Matter ◽  
Water Treatment ◽  
Carbon Source ◽  
Nitrogen Removal ◽  
Waste Water Treatment ◽  
Chemical Precipitation ◽  
Sewage Water ◽  
Laboratory Studies ◽  
Denitrification Process

Chemically coagulated sewage water gives an effluent low in both suspended matter and organics. To use chemical precipitation as the first step in waste water treatment improves nitrification in the following biological stage. The precipitated sludge contains 75% of the organic matter in the sewage and can by hydrolysis be converted to readily degradable organic matter, which presents a valuable carbon source for the denitrification process. This paper will review experiences from full-scale applications as well as pilot-plant and laboratory studies.

scholarly journals Training an asymmetric signal perceptron through reinforcement in an artificial chemistry

2014 ◽  
Vol 11 (93) ◽  
pp. 20131100 ◽  
Author(s):  
Peter Banda ◽  
Christof Teuscher ◽  
Darko Stefanovic
Keyword(s):  
State Of The Art ◽  
Chemical Species ◽  
Mass Action ◽  
Mass Action Kinetics ◽  
Dna Strand Displacement ◽  
Autonomous Adaptation ◽  
Biochemical Systems ◽  
Dna Strand ◽  
Logic Functions ◽  
Application Specific

State-of-the-art biochemical systems for medical applications and chemical computing are application-specific and cannot be reprogrammed or trained once fabricated. The implementation of adaptive biochemical systems that would offer flexibility through programmability and autonomous adaptation faces major challenges because of the large number of required chemical species as well as the timing-sensitive feedback loops required for learning. In this paper, we begin addressing these challenges with a novel chemical perceptron that can solve all 14 linearly separable logic functions. The system performs asymmetric chemical arithmetic, learns through reinforcement and supports both Michaelis–Menten as well as mass-action kinetics. To enable cascading of the chemical perceptrons, we introduce thresholds that amplify the outputs. The simplicity of our model makes an actual wet implementation, in particular by DNA-strand displacement, possible.

Nitrification and denitrification using a single biofilter packed with granular sulfur

2003 ◽  
Vol 47 (11) ◽  
pp. 153-156 ◽  
Author(s):  
J.-S. Kim ◽  
Y.-W. Hwang ◽  
C.-G. Kim ◽  
J.-H. Bae
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Domestic Wastewater ◽  
Organic Load ◽  
Low Carbon ◽  
Municipal Wastewater Treatment ◽  
Treatment Facility ◽  
Experimental Conditions ◽  
Nitrification And Denitrification ◽  
Denitrification Process

This study was performed to develop a granular sulfur packed nitrification/denitrification process employing a uniquely designed single biofilter, which treated a relatively low carbon loaded domestic wastewater taken from a primary clarifier at a municipal wastewater treatment facility. The system was tested on varying experimental conditions, e.g. inflow flow, organic load and nitrogen load. Regardless of flow rate being increased, SS and COD was unvaryingly removed up to 90 and 80%, respectively. Moreover, TKN was also decomposed up to 90%. Increase in COD load gradually led to escalating level of non-biodegradable compounds observed in effluent. Nitrification was accomplished as high as 92%, whereas denitrification was achieved up to approximately 87%. For a while, nitrification and denitrification were observed at 0.65 and 0.55 kg/m3áday, respectively. Eventually, T-N was decomposed as high as 46%. It was concluded that granular sulfur can be used for not only electron donor, but also for a media to properly treat low carbon loaded wastewater and to filter SS efficiently.

scholarly journals Impact of Temperature on Biological Denitrification Process

1970 ◽  
Vol 7 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Iswar Man Amatya ◽  
Bhagwan Ratna Kansakar ◽  
Vinod Tare ◽  
Liv Fiksdal
Keyword(s):  
Filtration Rate ◽  
Nitrate Nitrogen ◽  
Nitrate Removal ◽  
Biological Method ◽  
Biological Denitrification ◽  
Nitrite Nitrogen ◽  
Nitrogen Concentrations ◽  
In Series ◽  
Nitrate And Nitrite ◽  
Denitrification Process

Nitrate removal in groundwater was carried out by biological method of denitrification process. The denitrification and without denitrification were performed in two different sets of reactors. Each reactor consists of two columns connected in series packed with over burnt bricks as media. The filtration rate varied from 5.3 to 52.6 m/day for denitrification process. The ammonia, nitrate and nitrite nitrogen concentrations were measured at inlet, intermediate ports and outlet. The temperature varied from 10 to 30°C at 2°C intervals. The results demonstrated that high amount of nitrate nitrogen removed in groundwater at denitrification process. The nitrate nitrogen removed by denitrification varied from 3.50 to 39.08 gm/m3/h at influent concentration from 6.32 to 111.04 gm/m3/h. Denitrification was found more significant above 16°C.Key words: Over burnt brick, Denitrification, Filtration rate and TemperatureJournal of the Institute of Engineering, Vol. 7, No. 1, July, 2009 pp. 121-126doi: 10.3126/jie.v7i1.2070 

Separation of Free and Protein-Bound Ligand Molecules by Means of Protein-Coated Charcoal

1974 ◽  
Vol 20 (9) ◽  
pp. 1146-1149 ◽  
Author(s):  
Esper Mortensen
Keyword(s):  
Separation Method ◽  
Mass Action ◽  
Careful Evaluation ◽  
Experimental Conditions ◽  
Model Experiments

Abstract Separation of free and protein-bound ligand molecules by means of protein-coated charcoal has been studied in model experiments. The results can be described by applying the simple laws of mass action and dilution, and indicate the need for a careful evaluation of the charcoal that is being used and a testing against an ideal separation method whenever experimental conditions are determined or changed.

scholarly journals Implications of Limited Thermophilicity of Nitrite Reduction for Control of Sulfide Production in Oil Reservoirs

2016 ◽  
Vol 82 (14) ◽  
pp. 4190-4199 ◽  
Author(s):  
Tekle Tafese Fida ◽  
Chuan Chen ◽  
Gloria Okpala ◽  
Gerrit Voordouw
Keyword(s):  
Nitrate Reduction ◽  
Nitrite Reduction ◽  
Oil Fields ◽  
Microbial Consortia ◽  
Subsequent Reduction ◽  
Content Type ◽  
Reduction Activity ◽  
Pure Cultures ◽  
Nitrate And Nitrite ◽  
Reducing Bacteria

ABSTRACTNitrate reduction to nitrite in oil fields appears to be more thermophilic than the subsequent reduction of nitrite. Concentrated microbial consortia from oil fields reduced both nitrate and nitrite at 40 and 45°C but only nitrate at and above 50°C. The abundance of thenirSgene correlated with mesophilic nitrite reduction activity.ThaueraandPseudomonaswere the dominant mesophilic nitrate-reducing bacteria (mNRB), whereasPetrobacterandGeobacilluswere the dominant thermophilic NRB (tNRB) in these consortia. The mNRBThauerasp. strain TK001, isolated in this study, reduced nitrate and nitrite at 40 and 45°C but not at 50°C, whereas the tNRBPetrobactersp. strain TK002 andGeobacillussp. strain TK003 reduced nitrate to nitrite but did not reduce nitrite further from 50 to 70°C. Testing of 12 deposited pure cultures of tNRB with 4 electron donors indicated reduction of nitrate in 40 of 48 and reduction of nitrite in only 9 of 48 incubations. Nitrate is injected into high-temperature oil fields to prevent sulfide formation (souring) by sulfate-reducing bacteria (SRB), which are strongly inhibited by nitrite. Injection of cold seawater to produce oil creates mesothermic zones. Our results suggest that preventing the temperature of these zones from dropping below 50°C will limit the reduction of nitrite, allowing more effective souring control.IMPORTANCENitrite can accumulate at temperatures of 50 to 70°C, because nitrate reduction extends to higher temperatures than the subsequent reduction of nitrite. This is important for understanding the fundamentals of thermophilicity and for the control of souring in oil fields catalyzed by SRB, which are strongly inhibited by nitrite.

Evaluation of nitrate and perchlorate reduction using sulfur-based autotrophic and mixotrophic denitrifying processes

2015 ◽  
Vol 16 (1) ◽  
pp. 208-218 ◽  
Author(s):  
Deniz Uçar ◽  
Emine Ubay Çokgör ◽  
Erkan Şahinkaya
Keyword(s):  
Nitrate Reduction ◽  
Elemental Sulfur ◽  
Reduction Rate ◽  
Sulfate Concentration ◽  
Biological Reduction ◽  
Perchlorate Reduction ◽  
Guideline Value ◽  
Reduction Efficiency ◽  
Drinking Water Guideline ◽  
Denitrification Process

The biological reduction of nitrate and perchlorate was comparatively evaluated in autotrophic and mixotrophic bioreactors using elemental sulfur and/or methanol as the energy source. The mixotrophic reactor was supplemented with methanol at CH3OH/NO3−-N ratio of 1 or 1.4. The mixotrophic reactor completely reduced perchlorate in the feed up to 1,000 μg l−1. The autotrophic reactor also showed high perchlorate reduction performance and decreased perchlorate from 1,000 μg l−1 to around 33 μg l−1. Complete reduction of 25 mg NO3−-N l−1 was achieved in both reactors, corresponding to a maximum nitrate reduction rate of 300 mg NO3−-N l−1d−1 and 400 mg NO3−-N l−1d−1 in the autotrophic and mixotrophic processes, respectively. Autotrophic denitrification caused an increase of effluent sulfate concentration, which may exceed the drinking water guideline value of 250 mg l−1. In the mixotrophic denitrification process, the effluent sulfate concentration was controlled by adjusting the C/N ratio in the influent. Mixotrophic denitrification was stimulated by 25 mg l−1 methanol addition and 53% of influent nitrate was reduced by the heterotrophic process, which decreased the effluent sulfate concentration to half of the autotrophic counterpart. Therefore, the mixotrophic process may be preferred over the autotrophic process when effluent sulfate concentration is of concern and a higher perchlorate reduction efficiency is desired.

Sign in / Sign up

Export Citation Format

Share Document