Activated sludge population dynamics and wastewater treatment plant design and operation

2000 ◽  
Vol 41 (9) ◽  
pp. 217-225 ◽  
Author(s):  
J. Wanner ◽  
I. Ruzickova ◽  
O. Krhutkova ◽  
M. Pribyl
Keyword(s):  
Population Dynamics ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Full Scale ◽  
Phosphate Removal ◽  
Plant Design ◽  
Organotrophic Bacteria ◽  
Biological Methods ◽  
Dynamics Problems ◽  
And Control

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.

Biological phosphorus removal at an experimental full-scale plant in France

1987 ◽  
Vol 14 (2) ◽  
pp. 278-283 ◽  
Author(s):  
M. Florentz ◽  
M. C. Hascoet ◽  
F. Bourdon
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Activated Sludge ◽  
Phosphorus Removal ◽  
Flow Reactor ◽  
Treatment Plant ◽  
Full Scale ◽  
Phosphate Removal ◽  
Anaerobic Sludge ◽  
Nuclear Magnetic

In France, all phosphorus removal treatment has been based on precipitation by means of chemical reagents. With a view to reducing costs, a series of laboratory experiments was initiated and subsequently followed up by full-scale studies in early 1984 at the Saint-Mars-la-Jaille treatment plant. This is the first biological P-removal plant to be put on line in France.The plant operates at low loading levels with extended aeration. Nitrification–denitrification is achieved in controlled aerobic and nonaerobic zones through a multi-mini-step process in a plug–flow reactor. Complete nitrate removal results in a release of phosphorus during the anaerobic phase and, hence in a high level of phosphorus accumulation in the aerobic sludge.Phosphorus removal was optimized by replacing the thickener with a new flotation thickener to minimize P-release in the anaerobic sludge blanket. The phosphorus removal levels obtained varied from 35% at the outset of the study to 89% upon stabilization. This paper outlines the basic technical alterations made to ensure efficient phosphorus removal with this type of sewage plant as well as the analytical procedures used, and identifies the polyphosphates accumulated in activated sludge, on the basis of 31-phosphorus nuclear magnetic resonance (31P nmr).Results concerning phosphorus removal at low temperatures are also provided. Key words: activated sludge, wastewater treatment, biological phosphate removal, anaerobic conditions, restricted oxygen, nuclear magnetic resonance, flotation, temperature.

PILOT -SCALE, HIGH-STRENGTH INDUSTRIAL WASTEWATER TREATMENT EVALUATION BY MATHEMATICAL MODELLING

1994 ◽  
Vol 30 (3) ◽  
pp. 119-128
Author(s):  
Elemér Dobolyi ◽  
Imre Takács
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Full Scale ◽  
Phosphate Removal ◽  
Experimental Results ◽  
Plant Performance ◽  
Design Parameters ◽  
Plant Design ◽  
Effluent Standards

An existing rendering plant wastewater treatment facility has to be upgraded to meet the newly set British and more stringent EC effluent standards. After detailed analysis it turned out, that the existing treatment plant cannot be upgraded, a new plant has to be built. The rendering plant processes slaughterhouse wastes. The wastewater contains easily biodegradable organic substances, mainly organic acids, organic bonded nitrogen and ammonia. According to the new effluent standards the main task, besides the organic removal was the complete removal of nitrogen. The aim of this study was to find out the best available technology and the basic wastewater design data. For this purpose, on site pilot scale experiments were carried out. In several test runs the influent BOD and T K N have varied of between 1400-5500 and 460-1120 mg/l, respectively. Based on the experimental results, single-sludge nitrification-denitrification technology was selected for the full scale treatment plant. The plant was extended by chemical phosphate removal applying the post-precipitation method. In addition to the experimental schedule, a mathematical model of the plant was developed for two purposes.– to verify the applicability of the general activated sludge model under high concentration influent conditions, and– to generalize experimental results and provide a tool to predict plant performance under full scale conditions. On the basis of successful pilot plant experiments and model calibration, full scale plant design parameters were determined and presented. The full scale plant is under construction.

Molecular biological methods (DGGE) as a tool to investigate nitrification inhibition in wastewater treatment

2003 ◽  
Vol 47 (11) ◽  
pp. 165-172 ◽  
Author(s):  
N. Kreuzinger ◽  
A. Farnleitner ◽  
G. Wandl ◽  
R. Hornek ◽  
R. Mach
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Full Scale ◽  
Two Stage ◽  
Plant Laboratory ◽  
Biological Methods

Incomplete nitrification at an activated sludge plant for biological pre-treatment of rendering plant effluents led to a detailed investigation on the origin and solution of this problem. Preliminary studies revealed that an inhibition of ammonia oxidising microorganisms (AOM) by process waters of the rendering plant was responsible for the situation. We were able to show a correlation between the existence of specific AOM and nitrification capacity expressed as oxygen uptake rate for maximal nitrification (OURNmax). Only Nitrosospira sp. was found in the activated sludge of the rendering plant and another industrial wastewater treatment plant with problems in nitrification, while reference plants without nitrification problems showed Nitrosomonas spp. as the predominant ammonia oxidising bacteria. By accompanying engineering investigations and experiments (cross-feeding experiments, operation of a two-stage laboratory plant) with molecular biological methods (DGGE - Denaturing Gradient Gel Electrophoresis) we were able to elaborate an applicable solution for the rendering plant. Laboratory experiments with a two-stage process layout finally provided complete nitrification overcoming the inhibiting nature of process waters from the rendering plant. DGGE analysis of the second stage activated sludge from the laboratory plant showed a shift in population structure from Nitrosospira sp. towards Nitrosomonas spp. simultaneous to the increase of nitrification capacity. Nitrification capacities comparable to full-scale municipal wastewater treatment plants could be maintained for more than two months. As the design of wastewater treatment plants for nitrification is linked to the growth characteristics of Nitrosomonas spp., established criteria can be applied for the redesign of the full-scale plant.

System Identification and Control of the Activated Sludge Process by Use of a Statistical Model

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1161-1172 ◽  
Author(s):  
M. Hiraoka ◽  
K. Tsumura
Keyword(s):  
Control System ◽  
System Identification ◽  
Statistical Model ◽  
Activated Sludge ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Ar Model ◽  
Diurnal Changes ◽  
Activated Sludge Process ◽  
And Control

The authors have been developing a hierarchical control system for the activated sludge process which consists of an upper level system controlling long-term seasonal variations, a control system of intermediate level aiming at optimization of the process and a control system of lower level controlling diurnal changes or hourly fluctuations. The control system using the multi-variable statistical model is one of the most appropriate control systems based on the modern control theory, for applying the lower level control of the activated sludge process. This paper introduces our efforts for developing the reliable data acquisition system, the control experiments applying the AR-model, one of the statistical models which were conducted at a pilot plant and present studies on the system identification and control at a field sewage treatment plant.

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
Keyword(s):  
Population Dynamics ◽  
Statistical Analysis ◽  
Activated Sludge ◽  
Treatment Plant ◽  
Operating Conditions ◽  
Statistical Analyses ◽  
Operating Parameters ◽  
Aerobic Treatment

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.

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Operational Parameter ◽  
Mixed Liquor ◽  
Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

Biosolids odor reduction by solids inventory management in the secondary activated sludge treatment system

2009 ◽  
Vol 59 (2) ◽  
pp. 241-247 ◽  
Author(s):  
K. Sekyiamah ◽  
H. Kim
Keyword(s):  
Activated Sludge ◽  
Inventory Management ◽  
Process Parameters ◽  
Treatment Plant ◽  
Treatment System ◽  
Sludge Treatment ◽  
System A ◽  
Treatment Processes ◽  
Dominant Process ◽  
And Control

A wastewater treatment plant consists of unit processes designed to achieve specific waste reduction goals. Offensive odors associated with these treatment processes are a constant source of public complaints. The purpose of this study was to statistically determine the process parameters that influence the formation of volatile sulfur compounds (VSCs) in the secondary treatment system. A statistical model was developed to relate the process parameters to the formation of VSCs in this system. The model established that F/M ratio, sludge blanket depth and SSV60 were the dominant process parameters that influenced the formation of VSCs in the secondary sedimentation basin. This model provides a useful tool for plant engineers to predict and control the VSC formation in a secondary activated sludge treatment system.

scholarly journals Niche Differentiation among Three Closely RelatedCompetibacteraceaeClades at a Full-Scale Activated Sludge Wastewater Treatment Plant and Putative Linkages to Process Performance

2018 ◽  
Vol 85 (5) ◽  
Author(s):  
Veronica R. Brand ◽  
Laurel D. Crosby ◽  
Craig S. Criddle
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Niche Differentiation ◽  
Full Scale ◽  
Pure Oxygen ◽  
Operational Parameters ◽  
Metabolic Potential ◽  
Operational Conditions

ABSTRACTMultiple clades within a microbial taxon often coexist within natural and engineered environments. Because closely related clades have similar metabolic potential, it is unclear how diversity is sustained and what factors drive niche differentiation. In this study, we retrieved three near-complete Competibacter lineage genomes from activated sludge metagenomes at a full-scale pure oxygen activated sludge wastewater treatment plant. The three genomes represent unique taxa within theCompetibacteraceae. A comparison of the genomes revealed differences in capacity for exopolysaccharide (EPS) biosynthesis, glucose fermentation to lactate, and motility. Using quantitative PCR (qPCR), we monitored these clades over a 2-year period. The clade possessing genes for motility and lacking genes for EPS biosynthesis (CPB_P15) was dominant during periods of suspended solids in the effluent. Further analysis of operational parameters indicate that the dominance of the CPB_P15 clade is associated with low-return activated sludge recycle rates and low wasting rates, conditions that maintain relatively high levels of biomass within the system.IMPORTANCEMembers of the Competibacter lineage are relevant in biotechnology as glycogen-accumulating organisms (GAOs). Here, we document the presence of threeCompetibacteraceaeclades in a full-scale activated sludge wastewater treatment plant and their linkage to specific operational conditions. We find evidence for niche differentiation among the three clades with temporal variability in clade dominance that correlates with operational changes at the treatment plant. Specifically, we observe episodic dominance of a likely motile clade during periods of elevated effluent turbidity, as well as episodic dominance of closely related nonmotile clades that likely enhance floc formation during periods of low effluent turbidity.

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