Relationships between Population Dynamics and Operating Parameters in an Activated Sludge-Plant by Statistical Analysis

1992 ◽  
Vol 25 (4-5) ◽  
pp. 399-400 ◽  
Author(s):  
L. Cingolani ◽  
M. Cossignani ◽  
R. Miliani

Statistical analyses were applied to data from a series of 38 samples collected in an aerobic treatment plant from November 1989 to December 1990. Relationships between microfauna structure and plant operating conditions were found. Amount and quality of microfauna groups and species found in activated sludge proved useful to suggest the possible causes of disfunctions.

2019 ◽  
Author(s):  
María Victoria Pérez ◽  
Leandro D. Guerrero ◽  
Esteban Orellana ◽  
Eva L. Figuerola ◽  
Leonardo Erijman

ABSTRACTUnderstanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of three years, including a period of nine month of disturbance, characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons and thein situgrowth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the ribosomal RNA (rrn) operon. Despite only moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, as the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions.IMPORTANCEIn this work we investigated the response of microbial communities to disturbances in a full-scale activated sludge wastewater treatment plant over a time-scale that included periods of stability and disturbance. We performed a genome-wide analysis, which allowed us the direct estimation of specific cellular traits, including the rRNA operon copy number and the in situ growth rate of bacteria. This work builds upon recent efforts to incorporate growth efficiency for the understanding of the physiological and ecological processes shaping microbial communities in nature. We found evidence that would suggest that activated sludge could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. This paper provides relevant insights into wastewater treatment process, and may also reveal a key role for growth traits in the adaptive response of bacteria to unsteady environmental conditions.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2657
Author(s):  
Elwira Nowobilska-Majewska ◽  
Piotr Bugajski

The aim of this study was to determine the condition of activated sludge in the biologic reactor located in the collective wastewater treatment plant in Nowy Targ (Poland) based on OUR tests in the aspect of the impact of sludge’s concentration in the biologic reactor and dependence of BOD5/TN and BOD5/TP in wastewater flowing into the biologic reactor. The analysis was conducted based on test results from 61 samples of activated sludge taken from the biologic reactor and 61 samples of wastewater flowing into the biologic reactor. The analysis included the concentration of sludge in the biologic reactor. The following indicators were analyzed in wastewater flowing into the reactor: biochemical oxygen demand (BOD5), total nitrogen (TN) and total phosphorus (TP). The statistical analysis concerning the impact of the analyzed factors on oxygen uptake rate (OUR) tests was developed based on the Pearson’s correlation coefficient and partial correlation of many variables. Based on the results of the partial correlation analysis, nomograms were developed to determine the condition of activated sludge microorganisms (OUR) based on the BOD5/TN and BOD5/TP connection and knowledge of the sludge concentration in the bioreactor of the treatment plant. The presented nomograms can be formulated for each bioreactor based on activated sludge technology related the load of organic and biogenic pollutants in the wastewater flowing into the bioreactor and the concentration of the sludge in the bioreactor.


Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1941 ◽  
Author(s):  
Bartosz Szeląg ◽  
Jakub Drewnowski ◽  
Grzegorz Łagód ◽  
Dariusz Majerek ◽  
Ewa Dacewicz ◽  
...  

The paper presented the methodology for the construction of a soft sensor used for activated sludge bulking identification. Devising such solutions fits within the current trends and development of a smart system and infrastructure within smart cities. In order to optimize the selection of the data-mining method depending on the data collected within a wastewater treatment plant (WWTP), a number of methods were considered, including: artificial neural networks, support vector machines, random forests, boosted trees, and logistic regression. The analysis conducted sought the combinations of independent variables for which the devised soft sensor is characterized with high accuracy and at a relatively low cost of determination. With the measurement results pertaining to the quantity and quality of wastewater as well as the temperature in the activated sludge chambers, a good fit can be achieved with the boosted trees method. In order to simplify the selection of an optimal method for the identification of activated sludge bulking depending on the model requirements and the data collected within the WWTP, an original system of weight estimation was proposed, enabling a reduction in the number of independent variables in a model—quantity and quality of wastewater, operational parameters, and the cost of conducting measurements.


2012 ◽  
Vol 178-181 ◽  
pp. 633-636 ◽  
Author(s):  
Feng Chen ◽  
Xiu Lian Zhu ◽  
Wei Yu

Municipalsludge is refers to the product of sewage treatment plant, facing the huge number of municipalsludge, the disposal of the municipalsludge has aroused wide attention of all countries. Many studies consider that urban land use of the municipalsludge is the most effective method, However heavy metal accumulats in the sludge and the environment of the risk with agricultural appears day after day.The purpose of this study is: analysis the transfermation of heavy metals in the activated sludge system of various structures. put forward the solution of reducing heavy metal exceeded in the activated sludge treatment process.It appears that the coagulation can make colloid stabilized and sedimentation, can control the input of the heavy metal effectively; Adsorption of activated sludge to heavy metal is very fast, in 30 min basic reached adsorption balance, probably 80% or more;The change from oxygen to aerobic have great influence on Heavy metal biological adsorption;An aerobic digestion processes can reduce the volume and quality of sludge, but there is no enrichment role to heavy metal in sludge.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 265-271 ◽  
Author(s):  
M. S. Switzenbaum ◽  
T. R. Plante ◽  
B. K. Woodworth

A handbook has been written for control of activated sludge bulking for wastewater treatment plant operators in Massachusetts. In order to demonstrate the principles described in the handbook for filamentous organism identification and subsequent selective control, six Massachusetts activated sludge plants experiencing bulking problems were investigated. In addition, a survey was conducted to determine the extent of the filamentous bulking problem in Massachusetts. Dominant filamentous organisms in the aeration tank mixed liquor were identified to determine the probable cause of bulking problems. Plant data and operating conditions were also studied to verify the organism-cause relationship. Based on the sample and data analysis, selective control strategies were suggested to the plant operator to control or eliminate the bulking problem.


1996 ◽  
Vol 33 (6) ◽  
pp. 279-287 ◽  
Author(s):  
Jørgen Mikkelsen ◽  
Niels Nyholm ◽  
Bo Neergaard Jacobsen ◽  
Fei Chen Fredenslund

The SimpleTreat model of Struijs et al. (1991a,b) for chemical fate in a generic activated sludge type wastewater treatment plant (WWTP) has been examined together with an improved model version (vers. 2.1jm) which gives more flexibility in the specification of the WWTP design and operating conditions and which includes a more accurate description of the process of volatilization. Model predictions for 15 different organic chemicals have tentatively been compared with observed removals in three specific Danish WWTP's, all low loaded plants with nitrogen removal. Biodegradation rate constants were either default values for readily or inherently degradable chemicals proposed in the EU Technical Guidance Document on Environmental Risk Assessment of New and Existing Substances (EUTG), or were judged from literature data. The model predictions were generally in fair agreement with the observed removals although exceptions were noted. For 10 chemicals the data allowed estimations of “full scale” biodegradation rate constants by model calibration. Rate constants (extrapolated to 20°C reference temperature) ranged from 0.07 L/(g SS ·d) for pentachlorophenol to 12 L/(g SS ·d) for the every readily degradable compound, p-cresol. Finally, example calculations with parameter values representing a generic Danish WWTP have been compared with example results stated in the EUTG. The predicted emissions in the generic EU WWTP were up to 3-4 times less to water and air and the emission with excess sludge up to 10 times higher than the corresponding figures for an average Danish WWTP.


2000 ◽  
Vol 41 (9) ◽  
pp. 217-225 ◽  
Author(s):  
J. Wanner ◽  
I. Ruzickova ◽  
O. Krhutkova ◽  
M. Pribyl

The development and tasks of IAWQ specialist group on Activated Sludge Population Dynamics have been briefly described. The paper is aimed at three main topics of population dynamics, i.e., competition of nitrifying and organotrophic bacteria, population dynamics of enhanced biological phosphate removal, and activated sludge bulking and foaming. The population dynamics problems are illustrated on examples of Czech activated sludge plants. The examples were selected from a large national survey of activated sludge plants accomplished in 1995–1999. Nitrification proved to be the most difficult process to design and control in nutrient removal activated sludge systems. The survey of enhanced biological phosphate removal processes has shown that the arrangements used in the Czech Republic support well this process. The competition of PAOs with “G” bacteria in full-scale plants is less common than could be expected from previous laboratory studies. The phenomenon of anoxic phosphate uptake was also observed in full-scale plants. Traditional activated sludge separation problem of bulking was observed with much less frequency than expected. On the other hand, foaming caused by M. parvicella, N. limicola and by GALOs has become the most serious operation problem. The survey has also shown that physical rather than biological methods of foaming control are successfully applied in Czech activated sludge plants. The extent of foaming problems underlines the importance of a proper design and construction of final clarifiers.


mSystems ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
María Victoria Pérez ◽  
Leandro D. Guerrero ◽  
Esteban Orellana ◽  
Eva L. Figuerola ◽  
Leonardo Erijman

ABSTRACT Understanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of 3 years, including a 9-month period of disturbance characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons, and the in situ growth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the rRNA (rrn) operon. Despite moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, is the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. IMPORTANCE Disturbance is a key determinant of community assembly and dynamics in natural and engineered ecosystems. Microbiome response to disturbance is thought to be influenced by bacterial growth traits and life history strategies. In this time series observational study, the response to disturbance of microbial communities in a full-scale activated sludge wastewater treatment plant was assessed by computing specific cellular traits of genomes retrieved from metagenomes. It was found that the genomes observed in disturbed periods have more copies of the rRNA operon than genomes observed in stable periods, whereas the in situ mean relative growth rates of bacteria present during stable and disturbed periods were indistinguishable. From these intriguing observations, we infer that the length of the lag phase might be a growth trait that affects the microbial response to disturbance. Further exploration of this hypothesis could contribute to better understanding of the adaptive response of microbiomes to unsteady environmental conditions.


1996 ◽  
Vol 33 (12) ◽  
pp. 255-258 ◽  
Author(s):  
Olga Burica ◽  
Marjeta Strazar ◽  
Ivan Mahne

The recirculation activated sludge process with preanoxic treatment was applied for biological reduction of the nitrogen content in municipal wastewater at pilot plant level. The pilot plant of total volume 3 300 1 with an initial anoxic to aerobic volume ratio of 40 : 60 was fed with wastewater from the first heavily loaded aerobic stage of a local wastewater treatment plant. Experiments were run over the summer and winter periods, the influent wastewater temperature being approx 24°C and approx 10°C, respectively. Special attention was paid to the hydraulic retention time, the total as well as mineral nitrogen loading, the aerobic to anaerobic volume ratio, and to the energy demand for denitrification of oxidised mineral nitrogen forms. Under optimal operating conditions the effluent quality that could be achieved was about 10 mg/l of total nitrogen (74% removal) and less than 2 mg N/l mineral nitrogen (87% removal), while simultaneously 205 mg BOD5/l in the influent was reduced to less than 7mg O2/l in the effluent. It was found feasible from the pilot plant experiments to upgrade an existing two stage aerobic-anaerobic wastewater treatment plant to reduce nitrogen from the liquid fraction of municipal wastewater so as to meet effluent quality standards without much additional volume and without amending the energy source for bioconversion of oxidised mineral nitrogen to gaseous forms.


Sign in / Sign up

Export Citation Format

Share Document