Biological phosphorus removal at an experimental full-scale plant in France

1987 ◽  
Vol 14 (2) ◽  
pp. 278-283 ◽  
Author(s):  
M. Florentz ◽  
M. C. Hascoet ◽  
F. Bourdon
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Flow Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Phosphate Removal ◽  
Anaerobic Sludge ◽  
Nuclear Magnetic

In France, all phosphorus removal treatment has been based on precipitation by means of chemical reagents. With a view to reducing costs, a series of laboratory experiments was initiated and subsequently followed up by full-scale studies in early 1984 at the Saint-Mars-la-Jaille treatment plant. This is the first biological P-removal plant to be put on line in France.The plant operates at low loading levels with extended aeration. Nitrification–denitrification is achieved in controlled aerobic and nonaerobic zones through a multi-mini-step process in a plug–flow reactor. Complete nitrate removal results in a release of phosphorus during the anaerobic phase and, hence in a high level of phosphorus accumulation in the aerobic sludge.Phosphorus removal was optimized by replacing the thickener with a new flotation thickener to minimize P-release in the anaerobic sludge blanket. The phosphorus removal levels obtained varied from 35% at the outset of the study to 89% upon stabilization. This paper outlines the basic technical alterations made to ensure efficient phosphorus removal with this type of sewage plant as well as the analytical procedures used, and identifies the polyphosphates accumulated in activated sludge, on the basis of 31-phosphorus nuclear magnetic resonance (31P nmr).Results concerning phosphorus removal at low temperatures are also provided. Key words: activated sludge, wastewater treatment, biological phosphate removal, anaerobic conditions, restricted oxygen, nuclear magnetic resonance, flotation, temperature.

Activated sludge population dynamics and wastewater treatment plant design and operation

2000 ◽  
Vol 41 (9) ◽  
pp. 217-225 ◽  
Author(s):  
J. Wanner ◽  
I. Ruzickova ◽  
O. Krhutkova ◽  
M. Pribyl
Keyword(s):  
Population Dynamics ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Full Scale ◽  
Phosphate Removal ◽  
Plant Design ◽  
Organotrophic Bacteria ◽  
Biological Methods ◽  
Dynamics Problems ◽  
And Control

The development and tasks of IAWQ specialist group on Activated Sludge Population Dynamics have been briefly described. The paper is aimed at three main topics of population dynamics, i.e., competition of nitrifying and organotrophic bacteria, population dynamics of enhanced biological phosphate removal, and activated sludge bulking and foaming. The population dynamics problems are illustrated on examples of Czech activated sludge plants. The examples were selected from a large national survey of activated sludge plants accomplished in 1995–1999. Nitrification proved to be the most difficult process to design and control in nutrient removal activated sludge systems. The survey of enhanced biological phosphate removal processes has shown that the arrangements used in the Czech Republic support well this process. The competition of PAOs with “G” bacteria in full-scale plants is less common than could be expected from previous laboratory studies. The phenomenon of anoxic phosphate uptake was also observed in full-scale plants. Traditional activated sludge separation problem of bulking was observed with much less frequency than expected. On the other hand, foaming caused by M. parvicella, N. limicola and by GALOs has become the most serious operation problem. The survey has also shown that physical rather than biological methods of foaming control are successfully applied in Czech activated sludge plants. The extent of foaming problems underlines the importance of a proper design and construction of final clarifiers.

Biological dephosphatation by activated sludge under denitrifying conditions: pH influence and occurrence of denitrifying dephosphatation in a full-scale waste water treatment plant

1997 ◽  
Vol 36 (12) ◽  
pp. 75-82 ◽  
Author(s):  
T. Kuba ◽  
M. C. M. van Loosdrecht ◽  
J. J. Heijnen
Keyword(s):  
Activated Sludge ◽  
Phosphorus Removal ◽  
Ph Effect ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Phosphorus Release ◽  
Full Scale ◽  
Waste Water Treatment Plant ◽  
Batch Tests

The effect of pH on phosphorus release under anaerobic conditions was examined for denitrifying phosphorus removing bacteria (DPB) cultivated in an anaerobic-anoxic sequencing batch reactor. Also batch tests were conducted with activated sludge from a full-scale waste water treatment plant (WWTP) in order to investigate occurrence and contribution of DPB in phosphorus removal processes. In the experiments for the pH effect, enriched DPB sludge was maintained under anaerobic conditions with acetic acid (HAc) present at 5 different pH conditions (6.0∼8.0), and released phosphorus and consumed HAc concentrations were measured. When the biomass concentration was around 2.7 g-VSS/l, the observed P/C (released-P/consumed-HAc) ratios were 0.7, 1.1 and 1.2 g-P/g-C at pH=6, 7 and 8. At 4.2 g-VSS/l, the observed P/C ratios were 0.9, 1.3 and 1.2 g-P/g-C, respectively. The difference between the two experiments resulted from the endogenous phosphorus release. The same pH effect as observed for conventional anaerobic-aerobic SBR sludge, was obtained for the DPB sludge in the range of pH=6.0∼7.5. However due to precipitates formation at pH=8.0, the apparent P/C ratio was approximately 20% less than the ratio calculated from the biological released phosphorus concentration by DPB. From the results of the batch tests with activated sludge and observations on the full-scale WWTP, it was also shown that clearly denitrifying dephosphatation occurs and approximately 50% of the phosphorus removal occurs via denitrifying activities in the WWTP.

scholarly journals Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (<sup>1</sup>H-NMR) analysis and HPLC HULIS determination

2017 ◽  
Vol 17 (17) ◽  
pp. 10405-10421 ◽  
Author(s):  
Nicola Zanca ◽  
Andrew T. Lambe ◽  
Paola Massoli ◽  
Marco Paglione ◽  
David R. Croasdale ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
1H Nmr ◽  
Flow Reactor ◽  
Analytical Techniques ◽  
Water Soluble ◽  
Proton Nuclear Magnetic Resonance ◽  
Aerosol Mass ◽  
Polycarboxylic Acids ◽  
Nuclear Magnetic

Abstract. The study of secondary organic aerosol (SOA) in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a potential aerosol mass (PAM) oxidation flow reactor using α-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically relevant photochemical ageing timescales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization – proton nuclear magnetic resonance (1H-NMR) spectroscopy and HPLC determination of humic-like substances (HULIS). Results were compared with previous Aerodyne aerosol mass spectrometer (AMS) measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquires spectroscopic features comparable to those of ambient OA when exposed to at least 1  ×  1012 molec OH cm−3  ×  s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent OH exposure, the formation of HULIS is observed in both α-pinene SOA and in naphthalene SOA (maximum yields: 16 and 30 %, respectively, of total analyzed water-soluble organic carbon, WSOC), providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

scholarly journals Metabolic Pathway for Propionate Utilization by Phosphorus-Accumulating Organisms in Activated Sludge: 13C Labeling and In Vivo Nuclear Magnetic Resonance

2003 ◽  
Vol 69 (1) ◽  
pp. 241-251 ◽  
Author(s):  
Paulo C. Lemos ◽  
Luísa S. Serafim ◽  
Margarida M. Santos ◽  
Maria A. M. Reis ◽  
Helena Santos
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Activated Sludge ◽  
Tricarboxylic Acid Cycle ◽  
Glycogen Metabolism ◽  
Biological Phosphorus Removal ◽  
Monomer Composition ◽  
Production Of Hydrogen ◽  
Nuclear Magnetic

ABSTRACT In vivo 13C and 31P nuclear magnetic resonance techniques were used to study propionate metabolism by activated sludge in enhanced biological phosphorus removal systems. The fate of label supplied in [3-13C]propionate was monitored in living cells subjected to anaerobic/aerobic cycles. During the anaerobic phase, propionate was converted to polyhydroxyalkanoates (PHA) with the following monomer composition: hydroxyvalerate, 74.2%; hydroxymethylvalerate, 16.9%; hydroxymethylbutyrate, 8.6%; and hydroxybutyrate, 0.3%. The isotopic enrichment in the different carbon atoms of hydroxyvalerate (HV) produced during the first anaerobic stage was determined: HV5, 59%; HV4, 5.0%; HV3, 1.1%; HV2, 3.5%; and HV1, 2.8%. A large proportion of the supplied label ended up on carbon C-5 of HV, directly derived from the pool of propionyl-coenzyme A (CoA), which is primarily labeled on C-3; useful information on the nature of operating metabolic pathways was provided by the extent of labeling on C-1, C-2, and C-4. The labeling pattern on C-1 and C-2 was explained by the conversion of propionyl-CoA to acetyl-CoA via succinyl-CoA and the left branch of the tricarboxylic acid cycle, which involves scrambling of label between the inner carbons of succinate. This constitutes solid evidence for the operation of succinate dehydrogenase under anaerobic conditions. The labeling in HV4 is explained by backflux from succinate to propionyl-CoA. The involvement of glycogen in the metabolism of propionate was also demonstrated; moreover, it was shown that the acetyl moiety to the synthesis of PHA was derived preferentially from glycogen. According to the proposed metabolic scheme, the decarboxylation of pyruvate is coupled to the production of hydrogen, and the missing reducing equivalents should be derived from a source other than glycogen metabolism.

scholarly journals Characterizing source fingerprints and ageing processes in laboratory-generated secondary organic aerosols using proton-nuclear magnetic resonance (<sup>1</sup>H-NMR) analysis and HPLC HULIS determination

2017 ◽  
Author(s):  
Nicola Zanca ◽  
Andrew T. Lambe ◽  
Paola Massoli ◽  
Marco Paglione ◽  
David R. Croasdale ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
1H Nmr ◽  
Flow Reactor ◽  
Maximum Yield ◽  
Analytical Techniques ◽  
Proton Nuclear Magnetic Resonance ◽  
Aerosol Mass ◽  
Polycarboxylic Acids ◽  
Nuclear Magnetic

Abstract. The study of secondary organic aerosol (SOA) in laboratory settings has greatly increased our knowledge of the diverse chemical processes and environmental conditions responsible for the formation of particulate matter starting from biogenic and anthropogenic volatile compounds. However, characteristics of the different experimental setups and the way they impact the composition and the timescale of formation of SOA are still subject to debate. In this study, SOA samples were generated using a Potential Aerosol Mass (PAM) oxidation flow reactor using alpha-pinene, naphthalene and isoprene as precursors. The PAM reactor facilitated exploration of SOA composition over atmospherically-relevant photochemical aging time scales that are unattainable in environmental chambers. The SOA samples were analyzed using two state-of-the-art analytical techniques for SOA characterization – proton nuclear magnetic resonance (1H-NMR) spectroscopy and HPLC determination of humic-like substances (HULIS). Results were compared with previous Aerodyne aerosol mass spectrometer (AMS) measurements. The combined 1H-NMR, HPLC, and AMS datasets show that the composition of the studied SOA systems tend to converge to highly oxidized organic compounds upon prolonged OH exposures. Further, our 1H-NMR findings show that only α-pinene SOA acquire spectroscopic features comparable to those of ambient OA when exposed to at least 1*1012 molec OH /cm3*s OH exposure, or multiple days of equivalent atmospheric OH oxidation. Over multiple days of equivalent atmospheric OH exposure, the formation of HULIS is observed in both α-pinene SOA (maximum yield = 16 %) and in naphthalene SOA (maximum yield = 30 %), providing evidence of the formation of humic-like polycarboxylic acids in unseeded SOA.

An emerging technology: Nuclear magnetic resonance microscopy

1988 ◽  
Vol 46 ◽  
pp. 1000-1001
Author(s):  
M.J. Hennessy ◽  
E. Kwok
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Relaxation Times ◽  
Basic Research ◽  
Local Environment ◽  
Magnetic Resonance Images ◽  
Nmr Microscopy ◽  
Mri Scans ◽  
Temperature Relaxation ◽  
Nuclear Magnetic

Much progress in nuclear magnetic resonance microscope has been made in the last few years as a result of improved instrumentation and techniques being made available through basic research in magnetic resonance imaging (MRI) technologies for medicine. Nuclear magnetic resonance (NMR) was first observed in the hydrogen nucleus in water by Bloch, Purcell and Pound over 40 years ago. Today, in medicine, virtually all commercial MRI scans are made of water bound in tissue. This is also true for NMR microscopy, which has focussed mainly on biological applications. The reason water is the favored molecule for NMR is because water is,the most abundant molecule in biology. It is also the most NMR sensitive having the largest nuclear magnetic moment and having reasonable room temperature relaxation times (from 10 ms to 3 sec). The contrast seen in magnetic resonance images is due mostly to distribution of water relaxation times in sample which are extremely sensitive to the local environment.

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

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