Activated sludge foaming: can phage therapy provide a control strategy?

2018 ◽  
Vol 39 (3) ◽  
pp. 162 ◽  
Author(s):  
Steve Petrovski ◽  
Robert Seviour
Keyword(s):  
Activated Sludge ◽  
Control Strategy ◽  
Phage Therapy ◽  
Filamentous Bacteria ◽  
Global Problem ◽  
Double Stranded Dna ◽  
Reliable Methods ◽  
Activated Sludge Systems

Foaming in activated sludge systems is a global problem leading to environmental, cosmetic and operational problems. Proliferation of filamentous hydrophobic bacteria (including the Mycolata) are responsible for the stabilisation of foams. Currently no reliable methods exist to control these. Reducing the levels of the filamentous bacteria with bacteriophages below the threshold supporting foaming is an attractive approach to control their impact. We have isolated 88 bacteriophages that target members of the foaming Mycolata. These double stranded DNA phages have been characterised and are currently being assessed for their performance as antifoam agents.

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.

scholarly journals Characterization of the Genome of the Polyvalent Lytic Bacteriophage GTE2, Which Has Potential for Biocontrol of Gordonia-, Rhodococcus-, and Nocardia-Stabilized Foams in Activated Sludge Plants

2011 ◽  
Vol 77 (12) ◽  
pp. 3923-3929 ◽  
Author(s):  
Steve Petrovski ◽  
Robert J. Seviour ◽  
Daniel Tillett
Keyword(s):  
Activated Sludge ◽  
Rhodococcus Erythropolis ◽  
Lytic Bacteriophage ◽  
Content Type ◽  
Double Stranded Dna ◽  
The Family ◽  
Nocardia Otitidiscaviarum ◽  
Foam Production ◽  
Activated Sludge Systems

ABSTRACTHydrophobicActinobacteriaare commonly associated with the stabilization of foams in activated sludge systems. One possible attractive approach to control these foam-stabilizing organisms is the use of specific bacteriophages. We describe the genome characterization of a novel polyvalent DNA phage, GTE2, isolated from activated sludge. This phage is lytic forGordonia terrae,Rhodococcus globerulus,Rhodococcus erythropolis,Rhodococcus erythropolis,Nocardia otitidiscaviarum, andNocardia brasiliensis. Phage GTE2 belongs to the familySiphoviridae, possessing a characteristic icosahedral head encapsulating a double-stranded DNA linear genome (45,530 bp) having 10-bp 3′-protruding cohesive ends. The genome sequence is 98% unique at the DNA level and contains 57 putative genes. The genome can be divided into two components, where the first is modular and encodes phage structural proteins and lysis genes. The second is not modular, and the genes harbored there are involved in DNA replication, repair, and metabolism. Some have no known function. GTE2 shows promising results in controlling stable foam production by its host bacteria under laboratory conditions, suggesting that it may prove useful in the field as a biocontrol agent.

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.

Occurrence and significance of filamentous bacteria in pulp and paper activated sludge systems

2004 ◽  
Vol 50 (3) ◽  
pp. 39-48 ◽  
Author(s):  
J. Bergeron ◽  
C. Pelletier
Keyword(s):  
Activated Sludge ◽  
Pulp And Paper ◽  
Batch Reactors ◽  
Nutrient Deficiencies ◽  
Filamentous Bacteria ◽  
Growth Type ◽  
Conventional Activated Sludge ◽  
Mode Of Operation ◽  
Activated Sludge Systems ◽  
P Sources

A microbial survey of 27 activated sludge (AS) systems included 16 conventional activated sludge (CAS) systems, five sequential batch reactors (SBR) and six oxygen-activated sludge (OAS) systems, all treating pulp and paper effluents. The most prevalent filaments observed were Thiothrix (26%) and Type 021N (22%). The designs of the activated sludge systems seemed to have an effect on the filament types. We found Thiothrix to be the most common filament associated with bulking. For CAS systems, a completely mixed mode of operation promoted Thiothrix and Type 021N growth. Type 021N was favoured in CAS systems with food to microorganism (F/M) ratios higher than 0.2, and with dissolved oxygen (DO) residuals higher than 2 ppm, while Thiothrix generally proliferated at lower F/M ratio and DO residuals. Nutrient deficiencies as well as nutrient dosage variations were suspected in most of the systems having Thiothrix and Type 021N as the most prevalent filaments. Thiothrix appeared to prefer polyphosphate and/or ammonia rather than urea/phosphoric acid as N and P sources. Systems with aerobic selectors showed the lowest filament counts, while systems with no selectors showed the highest filament counts.

Potential Use of Step Feed Control Using the Biomass in the Settler

1993 ◽  
Vol 28 (11-12) ◽  
pp. 239-248 ◽  
Author(s):  
M. T. Sorour ◽  
G. Olsson ◽  
L. Somlyody
Keyword(s):  
Activated Sludge ◽  
Control Strategy ◽  
Pilot Scale ◽  
Control Potential ◽  
Feed Control ◽  
Biomass Activity ◽  
Widespread Availability ◽  
Potential Use ◽  
Activated Sludge Systems

In spite of the widespread availability of step feed configurations in activated sludge systems, little use has been made of their control potential. The main aim of this study is to provide a better understanding of applying step feed control considering the role of biomass activity in the settler. The control strategy was evaluated by simulating the dynamics of an activated sludge system. The model contains both biomass activity in the settler and step feed capabilities. The model and the strategy then have been evaluated against pilot scale and full scale experimental data.

scholarly journals Study of 16 Portuguese activated sludge systems based on filamentous bacteria populations and their relationships with environmental parameters

2015 ◽  
Vol 99 (12) ◽  
pp. 5307-5316 ◽  
Author(s):  
Liliana Araújo dos Santos ◽  
Vânia Ferreira ◽  
Marta Martins Neto ◽  
Maria Alcina Pereira ◽  
Manuel Mota ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Environmental Parameters ◽  
Filamentous Bacteria ◽  
Activated Sludge Systems

The Effect of Metallic and Ionic Species on the Performance of a Biological Effluent Treatment System

1977 ◽  
Vol 12 (1) ◽  
pp. 191-212
Author(s):  
B. Volesky ◽  
Q. Samak ◽  
P. Waller
Keyword(s):  
Activated Sludge ◽  
Inorganic Ions ◽  
Industrial Effluents ◽  
Original Data ◽  
Ionic Species ◽  
Threshold Concentration ◽  
Effluent Treatment ◽  
Organic Load ◽  
Metallic Ions ◽  
Activated Sludge Systems

Abstract Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays. From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel. Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.

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