In situ bioaugmentation of nitrification in the regeneration zone: practical application and experiences at full-scale plants

2006 ◽  
Vol 53 (12) ◽  
pp. 39-46 ◽  
Author(s):  
O. Krhutková ◽  
L. Novák ◽  
L. Pachmanová ◽  
A. Benáková ◽  
J. Wanner ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Low Temperatures ◽  
Wastewater Treatment Plants ◽  
Winter Season ◽  
Practical Application ◽  
The Common ◽  
Low Performance ◽  
Negative Factors ◽  
Rate Limiting

Nitrification is the rate-limiting process in the design of activated sludge process. It is especially unstable during the winter season (when the temperature of activated sludge mixed liquor drops below 13 °C). It is therefore difficult to meet the ammonia effluent standards in winter. The common way to compensate for low nitrification rates at low temperatures is to increase sludge retention time (SRT). However, the increase of SRT is accompanied by negative factors such as elevated sludge concentration, higher sludge loading of secondary clarifiers, formation of unsettleable microflocs, etc. The low performance of nitrification at low temperatures can also be compensated for by enhancing the nitrification population in activated sludge. This paper describes such a method called bioaugmentation of nitrification in situ. This procedure takes place in a so-called regeneration tank, which is situated in the return activated sludge stream. The results of the operation of two wastewater treatment plants with regeneration zones are described in this paper, together with some economic evaluation of the bioaugmentation method.

Substrate uptake by Gordonia amarae in activated sludge foams by FISH-MAR

2006 ◽  
Vol 54 (1) ◽  
pp. 39-45 ◽  
Author(s):  
E.L. Carr ◽  
K.L. Eales ◽  
R.J. Seviour
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Mycolic Acid ◽  
Substrate Uptake ◽  
Wastewater Treatment Process ◽  
Pure Cultures ◽  
Gordonia Amarae

Gordonia amarae is a right-angled branching filament belonging to the mycolic acid-containing Actinobacteria which is commonly found in many foaming activated sludge wastewater treatment plants. Although studies on different substrates as sole carbon sources by pure cultures of G. amarae have been carried out, none have examined substrate uptake by this organism in situ. Uptake of several hydrophilic and hydrophobic substrates by G. amarae was evaluated in situ using a combination of fluorescence in situ hybridization and microautoradiography. G. amarae could assimilate a range of both hydrophilic and hydrophobic substrates. From the data, G. amarae appears to be physiologically active under aerobic, anaerobic and anoxic condition (NO2 and NO3) for some substrates. This might explain why attempts to control foaming caused by G. amarae using anoxic and anaerobic selectors have been unsuccessful. This study emphasizes that bacteria can behave differently in situ to pure cultures and that it is important to evaluate the in situ physiology of these bacteria if we are to better understand their role in the wastewater treatment process.

Rheed Intensity Observation of AlAs and GaAs by in situ Etching Using Arsenic Tribromide

1995 ◽  
Vol 405 ◽  
Author(s):  
T. Kaneko ◽  
T. Säger ◽  
K. Eberl
Keyword(s):  
Low Temperatures ◽  
Reaction Rate ◽  
Etching Rate ◽  
Layer By Layer ◽  
Supply Rate ◽  
Limited Region ◽  
Continuous Increase ◽  
Higher Temperature ◽  
Rate Limiting

AbstractThe first in situ layer-by-layer etching of AlAs(100) surfaces has been observed by using RHEED intensity oscillations technique and is contrasted with the results obtained for the etching of GaAs(100). The experiments were conducted by introducing the etchant, arsenic tribromide, directly into a conventional MBE chamber without the use of any carrier gas. RHEED intensity oscillations during the etching of AlAs are observed between 350 and 760°C indicating a continuous increase in the etching rate with temperatures, with no supply rate limiting conditions being reached. Conversely, oscillations from GaAs reveal a reaction rate limited region at low temperatures (≤500°C) and a supply rate limited region at higher temperature(>500°C). The maximum selectivity in the etching rates between GaAs and AlAs is obtained at 450°C (40:1). The selectivity, and the ability to monitor the layer-by-layer process by RHEED intensity oscillations is foreseen to be of great importance for more controlled fabrications of AlAs and GaAs heterointerfaces.

Phylogenetic analysis and in situ identification of “Nostocoida limicola”-like filamentous bacteria in activated sludge from industrial wastewater treatment plants

2002 ◽  
Vol 46 (1-2) ◽  
pp. 99-104 ◽  
Author(s):  
J. Snaidr ◽  
C. Beimfohr ◽  
C. Levantesi ◽  
S. Rossetti ◽  
J. van der Waarde ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Industrial Wastewater ◽  
Wastewater Treatment Plants ◽  
Molecular Probes ◽  
Special Focus ◽  
Filamentous Bacteria ◽  
Industrial Wastewater Treatment ◽  
Biological Methods

The diversity of filamentous bacteria present in industrial wastewater treatment plants was analysed by a combination of classical and molecular-biological approaches. Many unknown filamentous bacteria were observed in about 80 screened activated sludge samples from different industries with sometimes severe bulking sludge problems. A special focus was paid to filaments which resembled “Nostocoida limicola”, a filamentous bacterium which was found to be present in many WWTPs. These filamentous bacteria are hardly cultivable and only one strain was obtained and maintained in co-culture with a yeast. The 16S rRNA sequences of several other “Nostocoida limicola”-like filamentous bacteria from different sludge samples were obtained by micromanipulation and different molecular-biological methods. The sequences were phylogenetically analyzed and specific molecular probes were developed and applied. The results clearly demonstrate that “Nostocoida limicola”-like filaments from industrial WWTPs are different from all other “Nostocoida limicola” types investigated so far. Our strains are affiliated to the alpha-subclass of Proteobacteria.

scholarly journals The ecology of the Chloroflexi in full-scale activated sludge wastewater treatment plants

2018 ◽  
Author(s):  
Marta Nierychlo ◽  
Aleksandra Miłobędzka ◽  
Francesca Petriglieri ◽  
Bianca McIlroy ◽  
Per Halkjær Nielsen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Spatial Arrangement ◽  
Full Scale ◽  
Substantial Contribution ◽  
Sludge Flocs ◽  
Hybridization Probes ◽  
Operational Problem

AbstractFilamentous bacteria belonging to the phylum Chloroflexi have received considerable attention in wastewater treatment systems for their suggested role in operational problem of impaired sludge settleability known as bulking. Their consistently high abundance in full-scale systems, even in the absence of bulking, indicates that they make a substantial contribution to the nutrient transformations during wastewater treatment. In this study, extensive 16S rRNA amplicon surveys of full-scale Danish WWTPs were screened to identify the most numerically important Chloroflexi genera. Fluorescencein situhybridization probes were designed for theirin situcharacterization. All abundant phylotypes of the phylum were identified as facultative anaerobic chemoorganotrophs involved in fermentation of sugars. These groups were all filamentous but differed in their morphology and spatial arrangement.‘CandidatusVilligracilis’ was predominantly located within the activated sludge flocs, where they possibly have structural importance, and their abundance was relatively stable. Conversely, the abundance of‘CandidatusAmarolinea’ was highly dynamic, relative to other genera, sometimes reaching abundances in excess of 30% of the biovolume, suggesting their likely role in bulking episodes. This study gives an important insight into the role of Chloroflexi in WWTPs, thus contributing to the broader goal of understanding the ecology of these biotechnologically important systems.

Identity, abundance and physiology of Aquaspirillum-related filamentous bacteria in activated sludge

2006 ◽  
Vol 54 (1) ◽  
pp. 237-245 ◽  
Author(s):  
T.R. Thomsen ◽  
C. Kragelund ◽  
P.H. Nielsen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Oligonucleotide Probe ◽  
Filamentous Bacteria ◽  
Type B ◽  
Anaerobic Conditions ◽  
Almost All

Microcolony-forming bacteria closely related to the genus Aquaspirillum in the Betaproteobacteria were recently observed to be abundant in many nutrient removal wastewater treatment plants. The developed oligonucleotide probe, Aqs997, however, occasionally also targeted some filamentous bacteria in activated sludge samples when fluorescence in situ hybridization was performed. In this study, the identity, abundance, and ecophysiology of these Aqs997-positive filamentous bacteria were studied in detail. Most of the Aqs997-positive filamentous bacteria could morphologically be identified as either Eikelboom Type 1701, Type 0041/0675 or possibly Type 1851, all characterized by epiphytic growth. They were found in almost all 21 wastewater treatment plants investigated. Two morphotypes were found. Type A filaments, which seemed to be the same genotype as the microcolony-forming bacteria targeted by probe Aqs997.Type B filaments also hybridized with probe GNS941, specific for the Chloroflexi phylum, so the true identity remains unclear. Aqs997-positive filaments usually stained Gram-negative, but Gram-positive filaments were also found, stressing the difficulties in identifying bacteria from morphology and simple staining results. Studies on the ecophysiology by microautoradiography showed that Aqs997-positive filamentous bacteria did not consume acetate and glucose, while some took up butyrate, mannose, and certain amino acids. Most likely, some Aqs997-positive filamentous bacteria were able to perform full denitrification such as the Aqs997-positive microcolony-forming bacteria, and some were able to store polyhydroxyalkanoates under anaerobic conditions, potentially being glycogen accumulating organisms.

Selector Volume in Pulp and Paper Activated Sludge Wastewater Treatment Plants – Bench Scale and Pilot Plant Studies

1994 ◽  
Vol 29 (5-6) ◽  
pp. 303-311
Author(s):  
J. Wessberg ◽  
T. Welander ◽  
M. Jönsson
Keyword(s):  
Activated Sludge ◽  
Pilot Plant ◽  
Wastewater Treatment Plants ◽  
Pulp And Paper ◽  
Volume Index ◽  
Sludge Volume Index ◽  
Bench Scale ◽  
Reference Process ◽  
Kraft Mill

Laboratory activated sludge reactors were operated on effluent wastewater from a kraft mill. Two of the three reactors were initially preceded with a “normal” size aerated selector, 2% of the total aerated volume, with unsatisfactory sludge volume index development. When the selectors were replaced by larger ones, 13% of the aerated volume, the sludge volume index could be kept below 50 ml/g for the selector processes while continuing to be higher and more unstable in the reference process. A pilot plant, operated in situ on the same wastewater, showed a comparable improvement in sludge volume index when its selector, 7% of the total volume, was replaced by one that constituted 13% of the total volume, corresponding to a selector load of 3 g BOD / g VSS * d. According to studies of the COD balance around one bench scale selector, the COD removal mechanism in the selector was respiration/assimilation rather than uptake/storage.

In situ microscopy as a tool for the monitoring of filamentous bacteria: a case study in an industrial activated sludge system dominated by M. parvicella

2015 ◽  
Vol 73 (6) ◽  
pp. 1333-1340
Author(s):  
Thiemo Dunkel ◽  
Philipe Ambrozio Dias ◽  
Erika Lizette de León Gallegos ◽  
Viola Tacke ◽  
Andreas Schielke ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Real Time ◽  
Wastewater Treatment Plants ◽  
Bulk Material ◽  
Volume Index ◽  
Filamentous Bacteria ◽  
Image Processing Algorithm ◽  
Polymerase Chain

The present study demonstrates the application of in situ microscopy for monitoring the growth of filamentous bacteria which can induce disturbances in an industrial activated sludge process. An in situ microscope (ISM) is immersed directly into samples of activated sludge with Microthrix parvicella as dominating species. Without needing further preparatory steps, the automatic evaluation of the ISM-images generates two signals: the number of individual filaments per image (ISM–filament counting) and the total extended filament length (TEFL) per image (ISM–online TEFL). In this first version of the image-processing algorithm, closely spaced crossing filament-segments or filaments within bulk material are not detected. The signals show highly linear correlation both with the standard filament index and the TEFL. Correlations were further substantiated by comparison with real-time polymerase chain reaction (real-time PCR) measurements of M. parvicella and of the diluted sludge volume index. In this case study, in situ microscopy proved to be a suitable tool for straightforward online-monitoring of filamentous bacteria in activated sludge systems. With future adaptation of the system to different filament morphologies, including cross-linking filaments, bundles, and attached growth, the system will be applicable to other wastewater treatment plants.

One-year operation of single household membrane bioreactor plant

2010 ◽  
Vol 61 (1) ◽  
pp. 217-226 ◽  
Author(s):  
Z. Matulova ◽  
P. Hlavinek ◽  
M. Drtil
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Membrane Bioreactor ◽  
Wastewater Treatment Plants ◽  
Winter Season ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Small Scale ◽  
One Year ◽  
Flexible Operation

This paper evaluates the results from a 12-month study of a single-household wastewater treatment plant with submerged membrane module (household MBR plant) that was monitored from winter to winter season. The samples were collected at least twice a week (an intensive research study at real conditions). The household MBR (membrane bioreactor) plant was linked to a family house with 4 residents. In this study the treatment plant was fed by real domestic wastewater. In contrast to most other experiments with small-scale WWTPs (wastewater treatment plants) carried out in laboratories and facilities of large municipal WWTPs (polygons) which guarantee stable and flexible operation but the characteristics of wastewater and activated sludge in these studies usually differ from those that occur in real small-scale/single-household WWTPs. One of the main goals of this research was to test the response of membrane and activated sludge to different conditions during real operation of the household MBR plant, such as a long period of zero influent/load, or vice versa the presence of a large amount of concentrated wastewater (e.g. during the weekend), very low winter temperatures (water temperature below 5–6°C), high pH values, and the presence of domestic detergents.

scholarly journals The proteome of Tetrasphaera elongata is adapted to changing conditions in wastewater treatment plants

2019 ◽  
Author(s):  
Florian-Alexander Herbst ◽  
Morten S. Dueholm ◽  
Reinhard Wimmer ◽  
Per Halkjær Nielsen
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Process Models ◽  
Energy Harvest ◽  
Biological Phosphorus Removal ◽  
Continuous Growth ◽  
Anoxic Conditions ◽  
E Coli

AbstractThe activated sludge in wastewater treatment plants (WWTP) designed for enhanced biological phosphorus removal (EBPR) experiences periodically changing nutrient and oxygen availability. Tetrasphaera is the most abundant genus in Danish WWTP and represent up to 20-30% of the activated sludge community based on 16S rRNA amplicon sequencing and quantitative fluorescence in situ hybridization analyses, although it is in low abundance in the influent wastewater. Here we investigate how Tetrasphaera can successfully out-compete most other microorganisms in such highly dynamic ecosystems. To achive this, we analyze the physiological adaptations of the WWTP isolate T. elongata str. LP2 during an aerobic to anoxic shift by label-free quantitative proteomics and NMR-metabolomics. Escherichia coli was used as reference organism as it shares several metabolic capabilities and is regularly introduced to wastewater treatment plants, but without succeeding there. When compared to E. coli, only minor changes in the proteome of T. elongata were observed after the switch to anoxic conditions. This indicates that metabolic pathways for anaerobic energy harvest were already expressed during the aerobic growth. This allows continuous growth of Tetrasphaera immediately after the switch to anoxic conditions. Metabolomics furthermore revealed that the substrates provided were exploited far more efficiently by Tetrasphaera than by E. coli. These results suggest that T. elongata prosper in the dynamic WWTP environment due to adaptation to the changing environmental conditions.Significance of the studyMembers of the genus Tetrasphaera are widely distributed and highly abundant in most well-operating WWTPs with EBPR configuration. However, despite their high abundance in situ, little is known about their physiology and ecological role. Although the importance of Tetrasphaera in engineered wastewater treatment systems is slowly being recognized, additional information is needed to understand the full extent of functions the microorganisms have in many of the essential biological processes in the WWTP. Such information may improve available process models and ultimately lead to better wastewater treatment as well as resource recovery. This study supplies proteomic and metabolomic data on the aerobic/anoxic adaptation of Tetrasphaera and provides a hypothesis on how Tetrasphaera might compete in dynamic engineered systems.

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