Modelling seasonal dynamics of Microthrix parvicella

2006 ◽  
Vol 54 (1) ◽  
pp. 189-198 ◽  
Author(s):  
T. Hug ◽  
W. Gujer ◽  
H. Siegrist
Keyword(s):  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Future Research ◽  
Model Structure ◽  
Filamentous Bacteria ◽  
Selection Mechanism ◽  
Research Activities ◽  
Microthrix Parvicella ◽  
Selection Mechanisms ◽  
Activated Sludge Systems

The filamentous bacteria “Microthrix parvicella” can cause serious bulking and scumming in wastewater treatment plants (WWTPs) all over the world. Decades of research have identified Microthrixas a specialized lipid consumer but could not clarify the processes that allow this organism to successfully compete in activated sludge systems. In this study we developed a model, based on ASM3, that describes the pronounced seasonal variations of Microthrix abundance observed in a full-scale WWTP. We hypothesize that low temperatures reduce the solubility of lipids and inhibit their uptake by non-specialized bacteria. The presented model structure and parameters successfully fit the measured data; however they do not necessarily reflect the only and true selection mechanism for Microthrix. This model is not yet to be used for prediction; it is rather a valuable research tool to coordinate the discussion and plan future research activities in order to identify the relevant selection mechanisms favoring Microthrix in activated sludge systems.

The use of rotifers for limiting filamentous bacteria Type 021N, a bacteria causing activated sludge bulking

2013 ◽  
Vol 67 (7) ◽  
pp. 1557-1563 ◽  
Author(s):  
Wioleta Kocerba-Soroka ◽  
Edyta Fiałkowska ◽  
Agnieszka Pajdak-Stós ◽  
Beata Klimek ◽  
Ewa Kowalska ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Filamentous Bacteria ◽  
Sludge Bulking ◽  
Microthrix Parvicella ◽  
Lecane Inermis

The excessive growth of filamentous bacteria and the resultant bulking of activated sludge constitute a serious problem in numerous wastewater treatment plants. Lecane inermis rotifers were previously shown to be capable of reducing the abundance of Microthrix parvicella and Nostocoida limicola in activated sludge. In the present study, the effectiveness of four Lecane clones in reducing the abundance of Type 021N filamentous bacteria was investigated. Three independent experiments were carried out on activated sludge from three different treatment plants. We found that Lecane rotifers are efficient consumers of Type 021N filaments.

The influence of PAX-14 on activated sludge systems and in particular on Microthrix parvicella

2002 ◽  
Vol 46 (1-2) ◽  
pp. 487-490 ◽  
Author(s):  
T. Roels ◽  
F. Dauwe ◽  
S. Van Damme ◽  
K. De Wilde ◽  
F. Roelandt
Keyword(s):  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Morphological Properties ◽  
Eu Directive ◽  
Solids Separation ◽  
Microthrix Parvicella ◽  
Separation Problems ◽  
Activated Sludge Systems

The amount of wastewater treatment plants (WWTP) dealing with solid separation problems has significantly increased since the new requirements of the EU Directive 271/91 on nutrient removal. In Flanders a number of the nutrient removal WWTP are affected by solid separation problems mostly attributed to Microthrix parvicella being the most common dominant species. The effect of dosing polyaluminium chloride (PAX-14) on activated sludge is illustrated for WWTP solids separation problems, in particular because of Microthrix parvicella. The effects of the addition of PAX-14 on the microbiology and the morphology of Microthrix parvicella were studied in 9 full-scale WWTPs. PAX-14 succeeded in reducing high SVI-values and controlled foaming problems whenever caused by Microthrix parvicella. Laboratory trials have shown that the dosage of PAX-14 should be less than 150 μL/L or 7 g Al3+/kg MLSS. At a dosage higher than 250 μL/L, an increase of free bacteria and a decrease of the protozoa activity are observed. In full-scale, PAX-14 is dosed at a concentration of 1.5 to 4.5 g Al3+/kg MLSS. Before addition, the mixed liquor scum layer – if present – should be removed. In our experience, the dosing should last for at least 3 weeks. During the first week, no drastic changes occur. At the end of the first week, an increase of SS and SVI is possible. The SVI and scum start to decrease after 10 to 15 days. The amount of filaments is reduced after 3 to 3½ weeks. The morphological properties of Microthrix parvicella change, while other filaments such as Nostocoida limicola and Nocardia spp. are not affected. This study proves that PAX-14 is effective in controlling bulking and foaming problems at WWTPs when they are due to Microthrix parvicella. Prediction of when the SVI will decrease and when addition should be stopped is possible.

Analysis and design of suitable model structures for activated sludge tanks with circulating flow

1999 ◽  
Vol 39 (4) ◽  
pp. 55-60 ◽  
Author(s):  
J. Alex ◽  
R. Tschepetzki ◽  
U. Jumar ◽  
F. Obenaus ◽  
K.-H. Rosenwinkel
Keyword(s):  
Activated Sludge ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
High Sensitivity ◽  
Suitable Model ◽  
Model Structure ◽  
Analysis And Design ◽  
Hydraulic Behaviour ◽  
Model Structures

Activated sludge models are widely used for planning and optimisation of wastewater treatment plants and on line applications are under development to support the operation of complex treatment plants. A proper model is crucial for all of these applications. The task of parameter calibration is focused in several papers and applications. An essential precondition for this task is an appropriately defined model structure, which is often given much less attention. Different model structures for a large scale treatment plant with circulation flow are discussed in this paper. A more systematic method to derive a suitable model structure is applied to this case. Results of a numerical hydraulic model are used for this purpose. The importance of these efforts are proven by a high sensitivity of the simulation results with respect to the selection of the model structure and the hydraulic conditions. Finally it is shown, that model calibration was possible only by adjusting to the hydraulic behaviour and without any changes of biological parameters.

scholarly journals Deep learning-based morphology classification of activated sludge flocs in wastewater treatment plants

2021 ◽  
Author(s):  
Hisashi Satoh ◽  
Yukari Kashimoto ◽  
Naoki Takahashi ◽  
Takashi Tsujimura
Keyword(s):  
Wastewater Treatment ◽  
Deep Learning ◽  
Activated Sludge ◽  
Morphological Change ◽  
Wastewater Treatment Plants ◽  
Filamentous Bacteria ◽  
Sludge Flocs

A deep learning-based two-label classifier 1 recognized a 20% morphological change in the activated flocs. Classifier-2 quantitatively recognized an abundance of filamentous bacteria in activated flocs.

Validation of a new image analysis procedure for quantifying filamentous bacteria in activated sludge

2014 ◽  
Vol 70 (6) ◽  
pp. 955-963 ◽  
Author(s):  
Ewa Liwarska-Bizukojc ◽  
Marcin Bizukojc ◽  
Olga Andrzejczak
Keyword(s):  
Image Processing ◽  
Image Analysis ◽  
Activated Sludge ◽  
Analysis Procedure ◽  
Automated Image Analysis ◽  
Filamentous Bacteria ◽  
Image Processing And Analysis ◽  
Manual Counting ◽  
Analysis Application ◽  
Activated Sludge Systems

Quantification of filamentous bacteria in activated sludge systems can be made by manual counting under a microscope or by the application of various automated image analysis procedures. The latter has been significantly developed in the last two decades. In this work a new method based upon automated image analysis techniques was elaborated and presented. It consisted of three stages: (a) Neisser staining, (b) grabbing of microscopic images, and (c) digital image processing and analysis. This automated image analysis procedure possessed the features of novelty. It simultaneously delivered data about aggregates and filaments in an individual calculation routine, which is seldom met in the procedures described in the literature so far. What is more important, the macroprogram performing image processing and calculation of morphological parameters was written in the same software which was used for grabbing of images. Previously published procedures required using two different types of software, one for image grabbing and another one for image processing and analysis. Application of this new procedure for the quantification of filamentous bacteria in the full-scale as well as laboratory activated sludge systems proved that it was simple, fast and delivered reliable results.

scholarly journals Conditions Favoring Proliferation of Glycogen Accumulating Organisms for Excess Biological Carbon Removal in Treating Nutrient Deficient Wastewater

2017 ◽  
Vol 61 (3) ◽  
pp. 149 ◽  
Author(s):  
Andrea Jobbágy ◽  
Bernadett Kiss ◽  
Vince Bakos
Keyword(s):  
Activated Sludge ◽  
Continuous Flow ◽  
The Other ◽  
N Availability ◽  
Filamentous Bacteria ◽  
Severe Deficiency ◽  
And Performance ◽  
Experimental Stage ◽  
Activated Sludge Systems ◽  
P Sources

Impact of marginal availability and severe deficiency of nitrogen on the growth of glycogen accumulating organisms (GAOs) and performance of anaerobic/aerobic activated sludge systems treating nutrient deficient wastewater was investigated at marginal availability and severe deficiency of phosphorus. Two continuous-flow lab-scale systems were operated simultaneously fed by model winery wastewater, one with marginal availability and the other one at severe deficiency of nitrogen. In the second experimental stage, marginal availability of P was converted into severe deficiency by interrupting external dosing.Common practice of dosing N- and P-sources to marginal availability caused enhanced proliferation of filamentous bacteria leading to poor biomass settling and instable operation. At marginal N-availability accumulation of GAOs started when conditions became deficient for phosphorus. In severe lack of nitrogen GAOs overgrew filaments, and outcompeted phosphorous accumulating organisms (PAOs) initially present in the seed. Stable and good performance could be maintained even after withdrawal of phosphorous dosing.

Performances of three R-AN-D-N wastewater treatment plants in the Czech Republic

2004 ◽  
Vol 50 (7) ◽  
pp. 249-255 ◽  
Author(s):  
Z. Bejvl ◽  
P. Matuška ◽  
J. Stara ◽  
P. Chudoba
Keyword(s):  
Wastewater Treatment ◽  
Czech Republic ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Industrial Effluents ◽  
Filamentous Bacteria ◽  
The Czech Republic ◽  
Treated Sewage ◽  
Nutrient Removal Efficiency

The evolution of Czech standards requires higher efficiency of nutrient removal from municipal wastewaters. At the beginning of the last decade of 20th century, a new activated sludge configuration called R-AN-D-N process has been described, successfully tested and now largely used at several wastewater treatment plants (WWTP) in the Czech republic. The main feature of the R-AN-D-N process is the introduction of a regeneration zone in sludge recycle, which enables to increase sludge age in the system without any substantial increase in WWTP volume. Performances of three Czech large WWTP with R-AN-D-N configuration have been monitored and compared within a period of one and a half years. The results confirmed excellent nutrient removal efficiency for wastewaters with different proportion between sewage and industrial effluents. Two of three monitored WWTP received wastewaters from breweries (Budweiser and Pilsner Urquell). The settleability of activated sludge from all three WWTP was correct, with SVI values usually ranging from 50 to 150 ml/g. Monitoring of sludge composition indicated proliferation of several filamentous bacteria, particularly types 0581, 0092 and M. parvicella. No severe bulking events were observed. Finally, the operational costs expressed in CZK (Czech crown: 1CZK = €0.0322) per cubic metre of treated sewage or per capita amounts respectively from 2.24 to 6.52, and from 285 to 342.

scholarly journals Identification and Ecophysiological Characterization of Epiphytic Protein-Hydrolyzing Saprospiraceae (“Candidatus Epiflobacter” spp.) in Activated Sludge

2008 ◽  
Vol 74 (7) ◽  
pp. 2229-2238 ◽  
Author(s):  
Yun Xia ◽  
Yunhong Kong ◽  
Trine Rolighed Thomsen ◽  
Per Halkjær Nielsen
Keyword(s):  
Activated Sludge ◽  
Industrial Wastewater ◽  
Wastewater Treatment Plants ◽  
Carbon Sources ◽  
Histochemical Staining ◽  
Filamentous Bacteria ◽  
Biological Phosphorus Removal ◽  
The Family ◽  
Biological Phosphorus

ABSTRACT The identity and ecophysiology of a group of uncultured protein-hydrolyzing epiphytic rods attached to filamentous bacteria in activated sludge from nutrient removal plants were investigated by using the full-cycle rRNA approach combined with microautoradiography and histochemical staining. The epiphytic group consists of three closely related clusters, each containing 11 to 16 clones. The closest related cultured isolate is the type strain Haliscomenobacter hydrossis (ATCC 27775) (<87% similarity) in the family Saprospiraceae of the phylum Bacteroidetes. Oligonucleotide probes at different hierarchical levels were designed for each cluster and used for ecophysiological studies. All three clusters behaved similarly in their physiology and were specialized in protein hydrolysis and used amino acids as energy and carbon sources. They were not involved in denitrification. No storage of polyphosphate and polyhydroxyalkanoates was found. They all colonized probe-defined filamentous bacteria belonging to the phyla Chloroflexi, Proteobacteria, and candidate phylum TM7, with the exception of cluster 1, which did not colonize TM7 filaments. The three epiphytic clusters were all widespread in domestic and industrial wastewater treatment plants with or without biological phosphorus removal, constituting, in total, up to 9% of the bacterial biovolume. A new genus, “Candidatus Epiflobacter,” is proposed for this epiphytic group in activated-sludge treatment plants, where it presumably plays an important role in protein degradation.

scholarly journals Activated Sludge Systems as Diferential Equations: A Fresh View on the Classical Models for Wastewater Treatment Plants

2014 ◽  
Vol 6 (2) ◽  
pp. 49-53
Author(s):  
Horea Olosutean ◽  
Letiţia Oprean
Keyword(s):  
Wastewater Treatment ◽  
Differential Equations ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Early Stage ◽  
Theory And Practice ◽  
Supplementary Data ◽  
Classical Models ◽  
Activated Sludge Models ◽  
Activated Sludge Systems

Abstract Present in the theory and practice of wastewater treatment for over 50 years in consistent numbers, activated sludge models are widely used by plant operators. The early stage models, based on differential equations were synthetized and reinterpreted, presenting new insides that can help to a better understanding of the processes involved in the wastewater treatment. A consistent symbology is presented, for a much homogenous perspective, and the obvious similarities between several equations from the models are pointed out. The incomplete information from the models is emphasized, showing their amount of providing supplementary data for plant operators and researchers in the field, as well as the causes leading to their drawbacks and the effects derived from these drawbacks.

Sign in / Sign up

Export Citation Format

Share Document