scholarly journals Validation of activated sludge plant performance for virus and protozoan reduction

2013 ◽  
Vol 3 (2) ◽  
pp. 140-147 ◽  
Author(s):  
A. R. Keegan ◽  
B. Robinson ◽  
P. Monis ◽  
M. Biebrick ◽  
C. Liston
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Plant Performance ◽  
Log10 Reduction ◽  
Validation Process ◽  
Indicator Microorganisms ◽  
Department Of Health ◽  
Combined Data ◽  
Plant Basis

Validation studies were undertaken at Adelaide metropolitan wastewater treatment plants to establish the actual log10 reduction values (LRVs) of pathogens (viruses and Cryptosporidium) across activated sludge plants (ASPs) as an alternative to accepting the default values attributed by the Department of Health and Ageing (DHA). Grab samples were collected across a 6-week period and assessed for pathogens (adenovirus and Cryptosporidium) and indicator microorganisms (sulphite-reducing clostridia and F-RNA bacteriophage). Through applying the validation process, the DHA has revised the default value for reduction of viruses with an increase from 0.5 log10 to 1 log10 while the value for protozoa remains at 0.5 log10 based on the combined data for a well-operated and maintained ASP. This provides the basis for considering further work at individual plants which may allow higher log credits to be obtained on a plant by plant basis.

Model-based evaluation of nitrogen removal in a tannery wastewater treatment plant

2004 ◽  
Vol 50 (6) ◽  
pp. 251-260 ◽  
Author(s):  
M.S. Moussa ◽  
A.R. Rojas ◽  
C.M. Hooijmans ◽  
H.J. Gijzen ◽  
M.C.M. van Loosdrecht
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Computer Modelling ◽  
Treatment Plant ◽  
Domestic Wastewater ◽  
Plant Performance ◽  
Accurate Estimation ◽  
Model Parameters ◽  
Biological Tests

Computer modelling has been used in the last 15 years as a powerful tool for understanding the behaviour of activated sludge wastewater treatment systems. However, computer models are mainly applied for domestic wastewater treatment plants (WWTPs). Application of these types of models to industrial wastewater treatment plants requires a different model structure and an accurate estimation of the kinetics and stoichiometry of the model parameters, which may be different from the ones used for domestic wastewater. Most of these parameters are strongly dependent on the wastewater composition. In this study a modified version of the activated sludge model No. 1 (ASM 1) was used to describe a tannery WWTP. Several biological tests and complementary physical-chemical analyses were performed to characterise the wastewater and sludge composition in the context of activated sludge modelling. The proposed model was calibrated under steady-state conditions and validated under dynamic flow conditions. The model was successfully used to obtain insight into the existing plant performance, possible extension and options for process optimisation. The model illustrated the potential capacity of the plant to achieve full denitrification and to handle a higher hydraulic load. Moreover, the use of a mathematical model as an effective tool in decision making was demonstrated.

Basis for the development of sustainable optimisation indicators for activated sludge wastewater treatment plants in the Republic of Ireland

2014 ◽  
Vol 71 (1) ◽  
pp. 131-138 ◽  
Author(s):  
G. T. Gordon ◽  
B. P. McCann
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Performance Improvement ◽  
Best Practice ◽  
Wastewater Treatment Plants ◽  
Plant Performance ◽  
Water Utility ◽  
Republic Of Ireland ◽  
Stakeholder Consultation ◽  
The Republic

This paper describes the basis of a stakeholder-based sustainable optimisation indicator (SOI) system to be developed for small-to-medium sized activated sludge (AS) wastewater treatment plants (WwTPs) in the Republic of Ireland (ROI). Key technical publications relating to best practice plant operation, performance audits and optimisation, and indicator and benchmarking systems for wastewater services are identified. Optimisation studies were developed at a number of Irish AS WwTPs and key findings are presented. A national AS WwTP manager/operator survey was carried out to verify the applied operational findings and identify the key operator stakeholder requirements for this proposed SOI system. It was found that most plants require more consistent operational data-based decision-making, monitoring and communication structures to facilitate optimised, sustainable and continuous performance improvement. The applied optimisation and stakeholder consultation phases form the basis of the proposed stakeholder-based SOI system. This system will allow for continuous monitoring and rating of plant performance, facilitate optimised operation and encourage the prioritisation of performance improvement through tracking key operational metrics. Plant optimisation has become a major focus due to the transfer of all ROI water services to a national water utility from individual local authorities and the implementation of the EU Water Framework Directive.

Benefits and drawbacks of thermal pre-hydrolysis for operational performance of wastewater treatment plants

2008 ◽  
Vol 58 (8) ◽  
pp. 1547-1553 ◽  
Author(s):  
P. Phothilangka ◽  
M. A. Schoen ◽  
B. Wett
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Treatment Plant ◽  
Full Scale ◽  
Plant Performance ◽  
Ammonia Release ◽  
Hydrolysis Process ◽  
Solids Content

This paper presents benefits and potential drawbacks of thermal pre-hydrolysis of sewage sludge from an operator's prospective. The innovative continuous Thermo-Pressure-Hydrolysis Process (TDH) has been tested in full-scale at Zirl wastewater treatment plant (WWTP), Austria, and its influence on sludge digestion and dewatering has been evaluated. A mathematical plant-wide model with application of the IWA Activated Sludge Model No.1 (ASM1) and the Anaerobic Digestion Model No.1 (ADM1) has been used for a systematic comparison of both scenarios—operational plant performance with and without thermal pre-hydrolysis. The impacts of TDH pre-hydrolysis on biogas potential, dewatering performance and return load in terms of ammonia and inert organic compounds (Si) have been simulated by the calibrated model and are displayed by Sankey mass flow figures. Implementation of full scale TDH process provided higher anaerobic degradation efficiency with subsequent increased biogas production (+75–80%) from waste activated sludge (WAS). Both effects—enhanced degradation of organic matter and improved cake's solids content from 25.2 to 32.7% TSS—promise a reduction in sludge disposal costs of about 25%. However, increased ammonia release and generation of soluble inerts Si was observed when TDH process was introduced.

scholarly journals Process schemes for future energy-positive water resource recovery facilities

2019 ◽  
Vol 79 (9) ◽  
pp. 1808-1820 ◽  
Author(s):  
Kimberly Solon ◽  
Mingsheng Jia ◽  
Eveline I. P. Volcke
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Water Resource ◽  
Municipal Wastewater ◽  
Energy Savings ◽  
Wastewater Treatment Plants ◽  
Resource Recovery ◽  
High Rate ◽  
Plant Performance ◽  
Municipal Wastewater Treatment

Abstract There are numerous successful studies on optimizing the performance of conventional activated sludge (CAS)-based wastewater treatment plants. However, recent studies have shown that a more significant improvement of the plant performance is achievable through integration of established technologies in novel process schemes. High-rate activated sludge system, chemically enhanced primary treatment, partial nitritation-anammox, partial nitrification-denitrification over nitrite and anaerobic digestion are integrated in two process schemes to determine to which extent energy savings and energy production can be achieved with these new process layouts compared to a CAS-based process scheme. The results presented in this paper show that there is potential for achieving future energy-positive water resource recovery facilities through novel integration of mature technologies for municipal wastewater treatment.

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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