Microscopic and enzymatic investigations on biofilms of wastewater treatment systems

1997 ◽  
Vol 36 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Tanja Gschlößl ◽  
Ingrid Michel ◽  
Marion Heiter ◽  
Christian Nerger ◽  
Verena Rehbein
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biological Properties ◽  
Organic Substances ◽  
Operational Conditions ◽  
Sludge Flocs ◽  
And Performance ◽  
The Stability

In biological wastewater treatment inorganic and organic substances are fixed and metabolized by mixed populations of microorganisms forming either activated sludge flocs or biofilms. Not only the type of wastewater but also the operational conditions promote the development of an adapted biocenosis of microorganisms with specialized enzymatic functions. Understanding the biological properties of the microorganisms, it is possible to assess the prevailing conditions in their natural environment. Regular microscopic and enzymatic investigations of activated sludge and biofilms thus improve the assessment of the stability of the processes and support troubleshooting in wastewater treatment plants. While the role of bacteria is often discussed, the importance of ciliated protozoes and metazoes for the maintenance of the stability of biofilm systems is rarely mentioned. In this paper we intend to show some new results of direct microscopic observations in different sorts of biofilm systems focussing upon ciliated protozoes and metazoes. Practical results will demonstrate the relation between enzymatic analysis, microscopic investigations and performance of biofilm systems.

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.

Control of Activated Sludge Bulking: From the Lab to the Plant

1989 ◽  
Vol 21 (6-7) ◽  
pp. 717-726 ◽  
Author(s):  
R. Pujol ◽  
P. Boutin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Common Type ◽  
Test Method ◽  
Mixing Zone ◽  
Operational Conditions ◽  
Sludge Bulking ◽  
Technical Aid

Activated sludge bulking often occurs in French wastewater treatment plants. Precise identification of filaments and better knowledge of their ecophysiology helped to clarify their re1ations with the operational conditions of plants. Effective techniques were therefore developed for control. The “mixing zone” is suitable for many cases of bulking ocurring in extended aeration plants (the most common type in France). A test method was developed to provide the elements for dimensioning the system. Unreserved cooperation between the owner of the plant, the manager, the SATESE (Service of technical aid to wastewater treatment plant managers) and specialized laboratories is required to implement such measures. Some cases, about which CEMAGREF was consulted, were examined; three of them are detailed and reasons for success or fai1ure are analysed. Seeking funds for the works too often leads to excessive delays.

Early warning-system for operation-failures in biological stages of WWTPs by on-line image analysis

2002 ◽  
Vol 46 (4-5) ◽  
pp. 117-124 ◽  
Author(s):  
W. Heine ◽  
I. Sekoulov ◽  
H. Burkhardt ◽  
L. Bergen ◽  
J. Behrendt
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biological Parameter ◽  
Chemical Parameters ◽  
Floc Size ◽  
Sludge Flocs ◽  
Operation Conditions ◽  
Physico Chemical ◽  
Microscopic Picture

By the observation and evaluation of the microscopic picture of activated sludge samples it is possible to introduce another biological parameter additional to conventional physico-chemical parameters for the control of biological stages of waste water treatment plants. Considering the fact that parameters like floc size and floc size distribution, structure of the flocs (compact/open), shape of the flocs (round/irregular) allow perceptions of the adjusted operation conditions of the biological stages, evidence for changing operation conditions or threatening operation disturbances can be recognised. This recognition takes place at a very early phase, because the morphology of activated sludge flocs reacts very fast to changing conditions. An automatic image analysis of activated sludge floc pictures would enable the introduction of a new sum parameter to enhance operation control of aeration tanks. By a statistical evaluation of the processed sludge images several parameters can be used to describe the alteration of activated sludge flocs characteristics. With these biological parameters it is possible to detect altered operation conditions or threatening or existing operation problems at an early phase. Thus it is possible to plan suitable countermeasures. Furthermore, the microscopic picture is the only parameter, that gives important information about the structure of the activated sludge flocs and the biozenosis. In comparison with the mainly used physico-chemical parameters, that just give information about the inlet and outlet of the wastewater treatment plants, the microscopic picture is the only parameter that gives information about the biology of the wastewater treatment process. By means of this biological parameter an improved control and regulation of the biological stages of wastewater treatment plants can be obtained.

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.

Variations of morphology of activated sludge flocs studied at full-scale wastewater treatment plants

2014 ◽  
Vol 36 (9) ◽  
pp. 1123-1131 ◽  
Author(s):  
Ewa Liwarska-Bizukojc ◽  
Anna Klepacz-Smółka ◽  
Olga Andrzejczak
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Full Scale ◽  
Sludge Flocs

scholarly journals Seasonality and Community Separation of Fungi in a Municipal Wastewater Treatment Plant

2020 ◽  
Vol 86 (18) ◽  
Author(s):  
Shaoqing Zhang ◽  
Fuqiang Fan ◽  
Fangang Meng
Keyword(s):  
Population Dynamics ◽  
Wastewater Treatment ◽  
Community Structure ◽  
Activated Sludge ◽  
Fungal Community ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Rare Taxa ◽  
Sludge Flocs

ABSTRACT Fungi are known to play important roles in pollutant transformation in activated sludge-based wastewater treatment plants (WWTPs). However, the seasonality and distributions of fungal populations in different-sized flocs have still remained largely unknown. In this study, seasonal population dynamics and community separation of fungi in a municipal WWTP across a 1-year period were investigated. We classified all taxa into six categories based on abundances to assess their roles and contributions to the whole community. The results showed that the rare taxa (<0.01%) contributed greatly to species richness (95.27%). Conversely, although low in species diversity, abundant taxa (≥1%) accounted for the majority (89.45%) of the total relative abundance, which suggested that a few core abundant fungi existed in the activated sludge ecosystem. The abundant, conditionally rare, and rare taxa contributed 30.14%, 31.11%, and 38.75%, respectively, to temporal shifts in community structure, and their abundances responded differently to environmental variables, suggesting that these three subcommunities exhibited a large difference in environmental sensitivity. Importantly, the results revealed seasonal dynamics of the whole fungal community and the subcommunities of all the microbial taxon categories, resulting in significant differences in community structures between warm and cold seasons. Furthermore, fungal diversity and the compositions of the whole community and subcommunities differed significantly among flocs of different sizes, which underlined the size-based fungal community separation in activated sludge of WWTPs. The findings of this work improved our understanding of fungal population dynamics and community separation in WWTPs. IMPORTANCE Fungi are important contributors to the various functions of activated sludge in wastewater treatment plants (WWTPs). Unlike previous studies, this work demonstrated the seasonality of the fungal community over a longer time span while it also systematically assessed the contributions of abundant, conditionally rare, and rare taxa to the whole community. Importantly, in the present study, we considered sludge flocs of a certain size range rather than the whole sludge flocs as a community. Our results revealed significant differences in fungal community structure among different-sized flocs, which supported the idea that size-based fungal community segregation is occurring in activated sludge ecosystems. The findings provide new insights into the dynamic changes or distribution of fungi in the bioaggregates of sludge flocs in WWTPs.

Influence of wastewater treatment plants' operational conditions on activated sludge microbiological and morphological characteristics

2015 ◽  
Vol 37 (2) ◽  
pp. 265-278 ◽  
Author(s):  
Elisavet Amanatidou ◽  
Georgios Samiotis ◽  
Eleni Trikoilidou ◽  
Dimitrios Tzelios ◽  
Avraam Michailidis
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Morphological Characteristics ◽  
Operational Conditions

scholarly journals Criticality Analysis Based on Reliability and Failure Propagation Effect for a Complex Wastewater Treatment Plant

2021 ◽  
Vol 11 (22) ◽  
pp. 10836
Author(s):  
Fredy Kristjanpoller ◽  
Nicolás Cárdenas-Pantoja ◽  
Pablo Viveros ◽  
Rodrigo Mena
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Real Data ◽  
Operational Effectiveness ◽  
Operational Conditions ◽  
Failure Propagation ◽  
And Performance ◽  
The Individual ◽  
Criticality Analysis

Wastewater treatment is a critical and necessary task every human settlement is obligated to address. If not, the consequences might be catastrophic, not just for humans but for the ecosystems as well, pushing research into finding new ways to improve wastewater treatment processes to make them safer and more efficient. Hence, there is a need to address matters, such as reliability and maintainability of Wastewater Treatment Plants (WWTP), when analyzing the availability and operational conditions. These should be addressed by analyzing the plant operational effectiveness impact (P-OEI), and in this article specifically, a WWTP study case to identify design flaws or improvement opportunities. A vital aspect of a complex system is to determine the contribution to resilience, reliability, and availability of every element embedded in the system. This is performed by adapting and applying the P-OEI methodology and real data of a WWTP located in Chile. This methodology breaks down the system into several levels of disaggregation similar to RBD methodology, analyzing the upstream for availability and the downstream for the P-OEI analysis from the system itself to the individual elements within subsystems. The potential impact on the overall system’s lack of efficiency is also quantified by an Expected Operational Impact (EOI) index, which is also calculated by the methodology. The P-OEI and EOI analyses performed in this study are powerful tools to assess the design and performance of complex systems and WWTP in particular.

PHA (polyhydroxyalkanoate) production potential of activated sludge treating wastewater

2002 ◽  
Vol 45 (12) ◽  
pp. 119-126 ◽  
Author(s):  
H. Takabatake ◽  
H. Satoh ◽  
T. Mino ◽  
T. Matsuo
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Organic Pollutants ◽  
Wastewater Treatment Plants ◽  
Recovery Process ◽  
Biodegradable Plastics ◽  
Operational Conditions ◽  
Conventional Activated Sludge ◽  
Dry Cell Weight ◽  
Dry Cell

The main purposes of wastewater treatment systems are to remove organic pollutants, but it would be very attractive if there were a way to recover the organic pollutants as valuable organic materials. One of the possible ways to recover organic pollutants in wastewater is to convert them into polyhydroxyalkanoates (PHAs), which are biodegradable plastics. In this study, 18 activated sludge samples in 4 wastewater treatment plants (WWTPs) in Tokyo, Japan, were evaluated for their potential to produce PHAs by aerobic batch experiments with excess supply of acetate as the sole carbon source. The activated sludge samples tested had the capability to accumulate PHA up to 18.8% of dry cell weight on average, with the range of 6.0% to 29.5%. The results showed that the maximum PHA content was dependent on the influent more than on the operational conditions of the activated sludge, and that conventional activated sludge produced PHA as much as anaerobic-aerobic activated sludge did. The PHA content achieved in this study is still low, and further improvement is needed to put into practice the recovery process of organic pollutants as biodegradable plastics by activated sludge.

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