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.

scholarly journals The present situation and trends of wastewater treatment in small settlements and rural areas of Lithuania

2019 ◽  
pp. 243-250
Author(s):  
Regimantas Dauknys
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Surface Waters ◽  
Rural Areas ◽  
Biological Treatment ◽  
Wastewater Treatment Plants ◽  
Present Situation ◽  
Treatment Facilities ◽  
Biological Filters ◽  
Activated Sludge Systems

This article presents the wastewater treatment in small settlements and rural areas ofLithuania, including descriptions of capacity and loading of wastewater treatment plants(WWTPs), types of treatment facilities, and development trends of biological treatmentfacilities. In 2000 Lithuania had 597 WWTPs with capacity up to 1000 m3/d, 95% of them arethe biological treatment plants. Today the most of these WWTPs are unloaded due to thetendency to centralise wastewater treatment in rural areas of Lithuania that were in the eightand ninth decades.In small settlements and rural areas of Lithuania the aeration facilities are predominant. In theeight and ninth decades practically only the activated sludge systems were built. The situationbegan to change in the last decade of the last century: the biological filters and soil filtrationfacilities with discharge into surface waters were applied more frequently, so the building ofaeration facilities started to decrease.

Efficiency of the Activated Sludge Model no. 3 for German wastewater on six different WWTPs

2003 ◽  
Vol 47 (11) ◽  
pp. 211-218 ◽  
Author(s):  
M. Wichern ◽  
M. Lübken ◽  
R. Blömer ◽  
K.-H. Rosenwinkel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Biological Parameters ◽  
Biological Phosphorus Removal ◽  
Activated Sludge Model ◽  
Biological Phosphorus ◽  
Activated Sludge Systems

In 1999, the Activated Sludge Model No. 3 by the IWA Task Group on Mathematical Modelling for the Design and Operation of Biological Wastewater Treatment was presented. The model is used for the simulation of nitrogen removal. The simulations in this paper were done on the basis of a new calibration of the ASM 3 by Koch et al., with the easily degradable COD measured by respiration. For modelling of EBPR the BioP-Module of Rieger et al., was used. Six German wastewater treatment plants were simulated during this research to test the existing set of parameters of the models on various large scale plants. It was shown that changes for nitrification and enhanced biological phosphorus removal in the set of biological parameters were necessary. Sensible parameters and recommended values are presented in this article. Apart from the values of the changed biological parameters, we will in our examination discuss the modelling of the different activated sludge systems and the influent fractioning of the COD. Two plants with simultaneous denitrification in the recirculation ditch (EBPR) are simulated, one with preliminary dentrification, one with intermittent denitrification (EBPR), one with cascade denitrification (EBPR), and one pilot plant according to the Johannesburg-process (EBPR) which was simulated over a period of three months.

scholarly journals Organic matter parameters in WWTP – a critical review and recommendations for application in activated sludge modelling

2021 ◽  
Author(s):  
Markus Ahnert ◽  
Thomas Schalk ◽  
Heike Brückner ◽  
Johannes Effenberger ◽  
Volker Kuehn ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Literature Review ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Data Sets ◽  
Composition Data ◽  
Comprehensive Literature Review ◽  
The Individual ◽  
Activated Sludge Models

Abstract This paper includes a comprehensive literature review of sludge composition data from wastewater treatment plants. 722 data sets from 249 sources were used to establish typical ratios between COD and solids-based parameters and to verify rule-of-thumb values, respectively. Confirmation of these typical ratios can also be accomplished by using biochemical composition data. It is shown that a correlation between data from proteins, lipids and carbohydrates analysis can be related to COD/VSS ratios. Finally, using the findings from the literature review, the organic and inorganic conversion factors of COD fractions in activated sludge models are adjusted to solids-based parameters. It was shown that with the adjustments of the factors and a partition of the particulate inert fraction into a fraction assigned to the influent and a fraction assigned to the endogenous products, a better agreement with the ratios of COD/VSS in the individual sludge streams can be established.

scholarly journals The capacity of wastewater treatment plants drives bacterial community structure and its assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Community Assembly ◽  
Bacterial Communities ◽  
Wastewater Treatment Plants ◽  
High Capacity ◽  
Operating Conditions ◽  
Rrna Gene

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.

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.

Controlling the Settling of Activated Sludge in Pulp and Paper Wastewater Treatment Plants

1999 ◽  
Vol 40 (11-12) ◽  
pp. 223-229 ◽  
Author(s):  
Frédéric Clauss ◽  
Christel Balavoine ◽  
Delphine Hélaine ◽  
Gaëtan Martin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Pulp And Paper ◽  
Organic Load ◽  
Forest Industry ◽  
Filamentous Bulking ◽  
Mineral Particles ◽  
Mineral Powder

Forest industry wastewaters are difficult to clean: hydraulic and organic load variations, filamentous bulking or pin-point flocs negatively impact depollution processes. The addition of a fine, mineral, talc-based powder, Aquatal, into the aeration tanks of wastewater treatment plants connected to pulp and paper factories has been successfully tested since end of '97. The first case-study presents full results obtained over a period of 18 months in a 20,000 p.e. plant connected to a paper factory. The mineral powder was regularly added to control sludge volume index, thereby ensuring low suspended solids concentration in the outfluent. Plant operators could easily adapt biomass concentration to match organic load variation, thereby maintaining pollution micro-organisms ratio constant. In a second case study, a trouble-shooting strategy was implemented to counteract filamentous bulking. A one-off, large dosage enabled the plant operator to deal effectively with poor settleability sludge and rapidly control sludge blanket expansion. In both cases, the main common characteristics observed were an increase in floc aggregation and the production of heavier and well-structured flocs. The sludge settling velocity increased and an efficient solid/liquid separation was obtained. After a few days, the mineral particles of Aquatal were progressively integrated into the sludge floc structure. When the mineral powder was added to the activated sludge in the aeration basin, chemical interactions frequently encountered with other wastewater treatment additives did not pose a problem. Moreover, with this mineral additive, the biological excess sludge displayed good thickening properties and dewatering was improved. Despite the addition of the insoluble mineral particles, the amount of wet sludge expelled did not increase. Aquatal offers a rapid solution to floc settleability problems which so frequently arise when physical or biological disorders appear in forest industry wastewater treatment plants.

PARAMETERS FOR DYNAMIC SIMULATION OF W ASTEW ATER TREATMENT PLANTS WITH HIGH-RATE AND LOW-RATE ACTIVATED SLUDGE TANKS

1994 ◽  
Vol 30 (4) ◽  
pp. 211-214 ◽  
Author(s):  
E. Brands ◽  
M. Liebeskind ◽  
M. Dohmann
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Dynamic Simulation ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
High Rate ◽  
Yield Coefficient ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
Low Rate

This study shows a comparison of important parameters for dynamic simulation concerning the highrate and low-rate activated sludge tanks of several municipal wastewater treatment plants. The parameters for the dynamic simulation of the single-stage process are quite well known, but parameters for the high-ratellow-rate activated sludge process are still missi ng, although a considerable number of wastewater treatment plants are designed and operated that way. At present any attempt to simulate their operation is restricted to the second stage due to missing data concerning growth rate, decay rate, yield coefficient and others.

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