How partial nitrification could improve reclaimed wastewater transport in long pipes

2001 ◽  
Vol 43 (10) ◽  
pp. 133-138 ◽  
Author(s):  
S. Delgado ◽  
M. Álvarez ◽  
L. E. Rodríguez-Gômez ◽  
S. Elmaleh ◽  
E. Aguiar
Keyword(s):  
Nitrification Rate ◽  
Nitrogen Compounds ◽  
Reclaimed Wastewater ◽  
First Order ◽  
Wastewater Disinfection ◽  
Nitrification Process ◽  
Wastewater Quality ◽  
Reuse System ◽  
Water Saturated ◽  
Denitrification Process

Reclaimed wastewater transport is studied in a concrete-lined cast iron pipe, where a nitrification-denitrification process occurs. The pipe is part of the Reuse System of Reclaimed Wastewater of South Tenerife (Spain), 0.6 m in diameter and 61 km long. In order to improve wastewater quality, at 10 km from the inlet there is injection of fresh water saturated in dissolved oxygen (DO), after which a fast nitrification process usually appears (less than two hours of space time). The amount of oxidized nitrogen compounds produced varies between 0.8 and 4.4 mg/l NOX--N. When DO has disappeared, a denitrification process begins. The removal of nitrite is complete at the end of the pipe, whereas the nitrate does not disappear completely, leaving a concentration of about 0.4-0.5 mg/l. For a COD/NOX--N ratio higher than 5, a first order nitrification rate in NOX--N has resulted, with the constant k20 = 0.079 h-1, for a NOX--N concentration range of 0.8-4.4 mg/l. Finally the following temperature dependency for the first order denitrification rate constant has been found : k = k20.1×15T-20. Although nitrogen could be used as nutrient in the agricultural reuse, its removal from reclaimed wastewater could be useful in order to diminish the chlorine needs for reclaimed wastewater disinfection.

Designing Experiments for Model Identification of the Nitrification Process

1991 ◽  
Vol 24 (6) ◽  
pp. 9-16 ◽  
Author(s):  
P. J. Ossenbruggen ◽  
H. Spanjers ◽  
H. Aspegren ◽  
A. Klapwijk
Keyword(s):  
Mechanistic Model ◽  
Nonlinear Differential Equations ◽  
Model Identification ◽  
Reaction Rates ◽  
Variable Coefficients ◽  
Model Specification ◽  
First Order ◽  
Interactive Behavior ◽  
Batch Tests ◽  
Nitrification Process

A series of batch tests were performed to study the competition for oxygen by Nitrosomonas and Nitrobacter in the nitrification of ammonia in activated sludge. Oxygen uptake rate (OUR) and dynamic (compartment) models describing the process are proposed and tested. The OUR model is described by a Monod relationship and the biogradation process by a set of first order nonlinear differential equations with variable coefficients. The results show a mechanistic model and ten reaction rates are sufficient to capture the interactive behavior of the nitrification process. Methods for model specification, calibrating, and testing the model and the design of additional experiments are described.

CHARACTERISATION OF THE NITRIFICATION PROCESS FOR DESIGN PURPOSES

1994 ◽  
Vol 30 (4) ◽  
pp. 47-56 ◽  
Author(s):  
O. Sinkjær ◽  
L. Yndgaard ◽  
P. Harremoës ◽  
J. L. Hansen
Keyword(s):  
Kinetic Theory ◽  
Nitrification Rate ◽  
Experimental Basis ◽  
Batch Tests ◽  
Mode Of Operation ◽  
Nitrification Process ◽  
Aerobic Reactor ◽  
The City ◽  
Specific Evaluation ◽  
Aerobic Sludge

Pilot plant experiments have been performed over a period of four years in order to establish an experimental basis for the upgrading of the treatment plants of the city of Copenhagen to nitrogen removal. The design chosen is based on the alternating mode of operation. Nitrification rates have been determined in batch tests on activated sludge extracted from the pilot plants and through the measuring of transient concentrations during the alternating mode of operation in the aerobic reactor. The data have been nonnalised to standard conditions by correcting them according to the kinetic theory. By monitoring the normalised nitrification rate it could be established that the nitrification process was occasionally inhibited. The aerobic sludge age required to maintain nitrification has been estimated. A specific evaluation has been made of the sensitivity of the required sludge age to the oxygen concentration and temperature.

MODELLING NITROGEN PROCESSES IN SOIL: MATHEMATICAL DEVELOPMENT AND RELATIONSHIPS

1976 ◽  
Vol 56 (2) ◽  
pp. 71-78 ◽  
Author(s):  
D. R. CAMERON ◽  
C. G. KOWALENKO
Keyword(s):  
Time Dependent ◽  
Rate Coefficients ◽  
Nitrification Rate ◽  
Order Kinetic ◽  
Nitrogen Flow ◽  
First Order ◽  
Interaction Term ◽  
Flow Pathways ◽  
Adsorption Desorption ◽  
Temperature Water

A small subsystem model was developed to simulate the major nitrogen flow pathways in an unsaturated soil treated with ammonium sulphate. A nonlinear Freundlich equilibrium model and a Langmuir kinetic model were used to describe mathematically the adsorption–desorption of soluble NH4+ to the exchangeable and clay-fixed phases, respectively. Time dependent, microbial mediated first-order kinetic models were used to quantify the ammonification and nitrification processes. The subsystem model was then used as a research tool to derive ammonification and nitrification rate coefficients for a preceding incubation experiment conducted using different soil moisture contents and temperatures. The model yields reasonably good fits to the observed data. A subsequent regression analysis relating the coefficients to temperature and moisture pointed out the importance of the temperature–water content interaction term in quantifying microbial mediated processes.

OPTIMISATION OF W ASTEW A TER TREATMENT PLANTS BY MEANS OF COMPUTER MODELS

1994 ◽  
Vol 30 (4) ◽  
pp. 181-190 ◽  
Author(s):  
René Dupont ◽  
Ole Sinkjær
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Operational Strategies ◽  
Nitrification Process ◽  
Computer Based ◽  
Calibration Tool ◽  
Denitrification Process

The objective of the work presented is to demonstrate how computer based models can be used to improve the effluent quality from wastewater treatment plants by optimisation of the operation. The investigation was carried out in connection with pilot plant investigations at Damhusllen Wastewater Treatment Plant in order to establish the design basis for upgrading the treatment plants in the city of Copenhagen. Calibration of the model was done with thorough characterisation of the wastewater and the activated sludge as the primary calibration tool. Special attention was paid to the nitrification process, which by previous investigations was shown to be occasionally inhibited. Model constants for the nitrification process were detennined from experiments. Default constants were used for nearly all other constants. The pilot plant was optimized with the calibrated model. Different operational strategies for improvement of the denitrification process were tested. The denitrification process was operated relatively poorly at the time for the optimisation. The calibration showed that it was possible to calibrate the model using the characterization of the wastewater and the activated sludge as the primary calibration tool. Further it was shown that the calihrated model could be used as a tool for optimising the operation of the pilot plant. The suggested operation correlated well with the practical realisable operation.

A note on the availability of organic nitrogen compounds in pot experiments

1925 ◽  
Vol 15 (3) ◽  
pp. 300-302 ◽  
Author(s):  
Edward M. Crowther
Keyword(s):  
Organic Nitrogen ◽  
Early Stage ◽  
Laboratory Work ◽  
Nitrogen Compounds ◽  
Pot Experiments ◽  
Nitrification Process ◽  
Set Up

In the course of an investigation on the nitrification process in soils a series of pot experiments was set up to compare the manurial actions of some typical organic nitrogen compounds. The laboratory work was interrupted at an early stage; the results of the pot experiments are briefly described in this note.

scholarly journals Effect of temperatures and alternating anoxic/oxic sequencing batch reactor (SBR) operating modes on extracellular polymeric substances in activated sludge

2020 ◽  
Author(s):  
Hongwei Sun ◽  
Chenjian Cai ◽  
Jixue Chen ◽  
Chunyu Liu ◽  
Guangjie Wang ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Extracellular Polymeric Substances ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
Batch Reactors ◽  
Sequencing Batch Reactors ◽  
Operating Modes ◽  
Nitrification Process ◽  
Main Component ◽  
Denitrification Process

Abstract In order to investigate the effect of temperatures and operating modes on extracellular polymeric substances (EPS) contents, three sequencing batch reactors (SBRs) were operated at temperatures of 15, 25, and 35 °C (R15 °C, R25 °C, and R35 °C, respectively), with two SBRs operated under alternating anoxic/oxic conditions (RA/O and RO/A, respectively). Results showed that higher contents of tightly bound EPS (TB-EPS) and total EPS appeared in R15 °C, while loosely bound EPS (LB-EPS) dominated in R35 °C. In all three kinds of EPS (LB-EPS, TB-EPS and total EPS) assessed, protein was the main component in R15 °C and R25 °C, while polysaccharides dominated in R35 °C. Moreover, compared with RO/A, RA/O was favorable for the production of the three kinds of EPS. Furthermore, three kinds of EPS and their components were augmented during the nitrification process, while they declined during the denitrification process under all conditions except for R35 °C.

Dissolved organic nitrogen (DON) during batch denitrification of low concentrations of nitrate using suspended and attached biomass

2015 ◽  
Vol 72 (11) ◽  
pp. 1896-1902
Author(s):  
D. N. Brandão ◽  
H. Spanjers ◽  
J. B. van Lier
Keyword(s):  
Surface Waters ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Treated Wastewater ◽  
Low Concentrations ◽  
Wastewater Disinfection ◽  
Attached Biomass ◽  
Final Effluent ◽  
By Products ◽  
Denitrification Process

The occurrence and removal of dissolved organic nitrogen (DON) is an issue of increasing importance for the reclamation of treated wastewater. Effluent DON may act as a precursor of disinfection by-products during wastewater disinfection and may contribute to eutrophication of receiving surface waters. The aim of this study was to understand the effect of the post-denitrification process on final effluent DON (organic nitrogen filtered by 0.45 μm pore size) concentration to further gain knowledge on how to optimize denitrifying filtration, in order to reach the required discharge standards. To evaluate DON variation, denitrification batch experiments were carried out with suspended and attached biomass under different shear conditions. For both conditions, with suspended and attached biomass, DON concentration did not increase or decrease during the denitrification process with addition of an external carbon source. Moreover, the increase of shear rate did not affect the DON concentration. Apparently, there is no direct link between DON evolution and the denitrification process itself.

scholarly journals Nitrification and its oxygen consumption along the turbid Chang Jiang River plume

2014 ◽  
Vol 11 (7) ◽  
pp. 2083-2098 ◽  
Author(s):  
S. S.-Y. Hsiao ◽  
T.-C. Hsu ◽  
J.-w. Liu ◽  
X. Xie ◽  
Y. Zhang ◽  
...  
Keyword(s):  
Ammonia Oxidation ◽  
River Mouth ◽  
Amoa Gene ◽  
Free Water ◽  
River Plume ◽  
Community Respiration ◽  
Ammonium Concentration ◽  
Nitrification Rate ◽  
Nitrification Process ◽  
Iron And Manganese

Abstract. Nitrification is a series of processes that oxidizes ammonia to nitrate, which contributes to hypoxia development in coastal oceans, especially in eutrophicated regions. The nitrification rate of bulk water (NRb) and particle free water (NRpf, particle > 3 μm eliminated) were determined along the Chang Jiang River plume in August 2011 by nitrogen isotope tracer technique. Measurements of dissolved oxygen (DO), community respiration rate (CR), nutrients, dissolved organic nitrogen (DON), total suspended matter (TSM), particulate organic carbon/nitrogen (POC / PON), acid-leachable iron and manganese on suspended particles and both archaeal and β-proteobacterial ammonia monooxygenase subunit A gene (amoA) abundance on size-fractioned particles (> 3 μm and 0.22–3 μm) were conducted. The NRb ranged from undetectable up to 4.6 μmol L−1 day−1, peaking at a salinity of ~ 29. NRb values were positively correlated with ammonium concentration, suggesting the importance of substrate in nitrification. In the river mouth and the inner plume, NRb was much higher than NRpf, indicating that the nitrifying microorganism is mainly particle associated, which was supported by its significant correlation with amoA gene abundance and TSM concentration. The estimated oxygen demands of nitrification accounted for 0.32 to 318% of CR, in which 50% samples demanded more oxygen than that predicted by by the Redfield model (23%), indicating that oxygen might not be the sole oxidant though DO was sufficient (> 58 μmol kg−1) throughout the observation period. The excess nitrification-associated oxygen demand (NOD) showed a tendency to occur at lower DO samples accompanied by higher acid-leachable Fe / Mn, which implied reactive Fe3+ / Mn4+ may play a role as oxidant in the nitrification process. Stoichiometric calculation suggested that reactive Fe on particles was 10 times the oxidant demand required to complete ammonia oxidation in the entire plume. The potential involvement of reactive iron and manganese in the nitrification process in oxygenated water further complicated nitrogen cycling in the turbid river plume.

Photochemical combustion of organic matter in sea water, for nitrogen, phosphorus and carbon determination

1968 ◽  
Vol 48 (1) ◽  
pp. 143-152 ◽  
Author(s):  
F. A. J. Armstrong ◽  
Susan Tibbitts
Keyword(s):  
Organic Matter ◽  
Sea Water ◽  
Phosphorus Compounds ◽  
Nitrogen Compounds ◽  
English Channel ◽  
First Order ◽  
First Order Kinetics ◽  
Channel Water ◽  
Carbon Determination ◽  
Nitrogen Phosphorus

A photochemical reactor, using a medium power mercury arc lamp for oxidation of organic matter in sea water, is described. The decomposition of some known compounds in distilled water and in sea water, using a 380 W lamp, was followed. First order kinetics with rate constants in the range 0·2–4·0 h−1 were observed. All the nitrogen compounds tested, including urea and some of its derivatives, were oxidized quantitatively. Breakdown of phosphorus compounds was rapid, but polyphosphate esters yielded polyphosphate ion which was only slowly hydrolysed to reactive orthophosphate. If polyphosphate is to be determined, hydrolysis by heating with acid should follow the irradiation. Some samples of English Channel water contained 0·02-0–05 fig-axom P/1. as organic polyphosphate.

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