Impact of seeding with nitrifying bacteria on nitrification process efficiency

2001 ◽  
Vol 43 (1) ◽  
pp. 155-164 ◽  
Author(s):  
E. Plaza ◽  
J. Trela ◽  
B. Hultman
Keyword(s):  
Simple Model ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Process Efficiency ◽  
Nitrifying Bacteria ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Nitrification Process ◽  
High Fraction

Seeding of nitrifying bacteria into the activated sludge process was studied both theoretically and experimentally. A simple model was developed for prediction of the effects of seeding of nitrifying bacteria from a separate stage into the activated sludge process. The purpose of seeding is to improve the treatment results and the process stability as well as to decrease the volume requirements of the process. Pilot plant studies were carried out at the Uppsala municipal wastewater treatment plant in order to evaluate the effects of seeding. One line was supplied with supernatant from dewatering of digested sludge and the nitrification process gave an activated sludge with a high fraction of nitrifying bacteria, suitable for seeding. The other line was supplied with pre-precipitated wastewater and with the excess sludge from the line treating the supernatant. The experimental results showed that nitrification could be obtained at sludge ages that would otherwise preclude nitrification. Performance relationships for the system developed, based on laboratory and on-line measurements were studied and are presented. The studies show that seeding may decrease the necessary volume needs for a stable nitrification process and that the effects could be predicted by use of a simple model.

Application of Inertial Effect in Activated Sludge Process

2014 ◽  
Vol 955-959 ◽  
pp. 2080-2082
Author(s):  
Hong Mei Liu ◽  
Gang Zhu ◽  
Ke Zhao ◽  
Zhuang Liu
Keyword(s):  
Water Quality ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Hydraulic Retention Time ◽  
Treatment Plant ◽  
First Grade ◽  
Inertial Effect ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Cold Winter

The inertial effect applied to activated sludge process, the practice shows that in energy efficiency and reduce the hydraulic retention time it is obvious than not using the inertial effect. In cold winter areas to ensure water quality can meet the first grade A standard of "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant" (GB18918-2002)

ANFIS Based Effluent pH Quality Prediction Model for an Activated Sludge Process

2013 ◽  
Vol 845 ◽  
pp. 538-542 ◽  
Author(s):  
Muhammad Sani Gaya ◽  
Norhaliza Abdul Wahab ◽  
Yahya M. Sam ◽  
Sharatul Izah Samsuddin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Ph Value ◽  
Treatment Plant ◽  
Quality Prediction ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Anfis Model ◽  
Inference System

Activated sludge process is the most efficient technique used for municipal wastewater treatment plants. However, a pH value outside the limit of 6-9 could inhibit the activities of microorganisms responsible for treating the wastewater, and low pH value may cause damage to the treatment system. Therefore, prediction of pH value is essential for smooth and trouble-free operation of the process. This paper presents an adaptive neuro-fuzzy inference system (ANFIS) model for effluent pH quality prediction in the process. For comparison, artificial neural network is used. The model validation is achieved through use of full-scale data from the domestic wastewater treatment plant in Kuala Lumpur, Malaysia. Simulation results indicate that the ANFIS model predictions were highly accurate having the root mean square error (RMSE) of 0.18250, mean absolute percentage deviation (MAPD) of 9.482% and the correlation coefficient (R) of 0.72706. The proposed model is efficient and valuable tool for the activated sludge wastewater treatment process.

Experiences in wastewater characterization and model calibration for the activated sludge process

1996 ◽  
Vol 33 (12) ◽  
pp. 89-98 ◽  
Author(s):  
Xu Shulan ◽  
Bengt Hultman
Keyword(s):  
Activated Sludge ◽  
Model Calibration ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Simulation Models ◽  
Activated Sludge Process ◽  
Model Simplification ◽  
Municipal Wastewater Treatment ◽  
Oxygen Utilization ◽  
Parameter Values

Simulation models of the activated sludge process are believed to be a useful tool for process optimization and trouble-shooting at today's treatment plant. However, the application of the models is limited at most treatment plants due to lack of advanced input of parameter values required by the model. Simplification of the procedures of wastewater characterization was investigated. Characterization work was reduced to two oxygen utilization measurements and two COD analyses. Model calibration is demonstrated with experimental data from Kungsängen municipal wastewater treatment plant in Uppsala, Sweden.

Operation and Performance of a New Activated Sludge Process: The Contact Stabilization Extended Aeration Hybrid

1982 ◽  
Vol 14 (1-2) ◽  
pp. 367-380
Author(s):  
B H Paepcke ◽  
P H Jones
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Lower Cost ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Process Stability ◽  
Aeration Process ◽  
And Performance

In this study the operation and performance of a contact stabilization process operating under the extended aeration mode is examined. Data was obtained during a detailed plant study carried out at a full scale municipal wastewater treatment plant. This new hybrid activated sludge process has good process stability like the conventional extended aeration process, but achieves this with a significantly smaller aeration tank volume and therefore lower cost.

Performance analysis of anoxic selector in upgrading activated sludge process in tropical climate

2005 ◽  
Vol 52 (4) ◽  
pp. 27-37 ◽  
Author(s):  
Y.S. Cao ◽  
K.H. Teo ◽  
W.A. Yuen ◽  
W.Y. Long ◽  
B. Seah
Keyword(s):  
Activated Sludge ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Stable State ◽  
Tropical Climate ◽  
Reaction Rates ◽  
Volume Index ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Sludge Settleability

The paper describes and analyses the performance of anoxic selectors in upgrading activated sludge process in a municipal wastewater treatment plant under tropical climate, where poor sludge settleability is a problem due to elevated temperature. Site monitoring and laboratory experiment were conducted to study the denitrification, sludge settleability, kinetics, mass balance, pH and alkalinity variation in the system. The sludge settleability measured in Sludge Volume Index (SVI) was observed to improve with the increasing degree of denitrification in the anoxic selector. Under well-developed stable state, an average SVI value of 136 ml/g was achieved, which was significantly lower than the value of 250 ml/g before the application of anoxic selector. The specific reaction rates for denitrification and nitrification at 30°C were 0.06 mg NO3-N/mg MLSS day and 0.08 mg NH4-N/mg MLSS day, respectively. The overall efficiencies of nitrification and denitrification were 86 percent and 55.4 percent, respectively, with an alkalinity recovery ratio of 15.4 percent. 32 percent of total COD removed was used up as electron donor in the denitrification process. However, due to absence of the internal Mixed Liquor Recirculation (MLR), a higher degree of denitrification occurred in the secondary sedimentation tank than in the anoxic zone. Issues for further studies are also discussed.

Design and operation of a wastewater treatment plant treating low concentration of municipal wastewater

1998 ◽  
Vol 38 (3) ◽  
pp. 167-172
Author(s):  
Jin Duanyao ◽  
Wang Baozhen ◽  
Wang Lin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Primary Treatment ◽  
Ammonia Nitrogen ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Foshan City

The Zhen'an Wastewater Treatment Plant in Foshan City, Guangdong Province, China is a newly built large municipal wastewater treatment plant in south China, situated in the southeast of the famous ancient Foshan City, has a treatment capacity of 100,000 m3/d, serves an area of 32 km2 and 220,000 P. E., occupies 7 ha area with a total investment of 220 million RMB (about 26.5 million U.S dollar), which was put into operation in December 1995. As it is difficult to design and operate the wastewater treatment plant because of the low organic concentration of its influent, the simplified A/O activated sludge process without primary treatment for simultaneous removal of phosphorus and ammonia nitrogen was employed to design the plant, by which, the wastewater is treated very well, with higher effluent quality than the traditional activated sludge process, while the capital and O/M costs are lower than the latter.

Biosensor-based control of nitrification inhibitor in municipal wastewater treatment plants

2006 ◽  
Vol 53 (4-5) ◽  
pp. 357-366 ◽  
Author(s):  
Y. Okayasu ◽  
H. Tanaka ◽  
T. Inui ◽  
Y. Tanaka
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Nitrification Inhibitor ◽  
Nitrifying Bacteria ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants ◽  
The Impact

The effect of potassium cyanide (KCN) on nitrification processes in municipal wastewater treatment plants was studied by batch nitrification tests, which indicated that nitrification processes tend to be inhibited at a lower KCN concentration than the present discharge standard to sewerage. The experiment of the biosensor using nitrifying bacteria was also conducted for continuous monitoring of nitrification inhibitor in influent wastewater, and demonstrated that the biosensor can detect KCN at as low as EC10 of the abovementioned batch nitrification test. Moreover, to determine the effectiveness of application of the biosensor to avoid the impact of KCN due to an accidental spillage in a sewerage system, KCN was intentionally injected into the experimental models of activated sludge process equipped both with and without the biosensor. The model with the biosensor that could detect KCN could divert the wastewater including KCN to a refuge tank, which resulted in the avoidance of upset of the activated sludge process. On the other hand, the model without the biosensor was upset in the nitrification process due to KCN. Such differences demonstrate the effectiveness of the biosensor applied to countermeasures of an accidental spillage of toxic chemicals to avoid upset of nitrification in municipal wastewater treatment plants.

scholarly journals Erythromycin Resistance-Conferring Plasmid pRSB105, Isolated from a Sewage Treatment Plant, Harbors a New Macrolide Resistance Determinant, an Integron-Containing Tn402-Like Element, and a Large Region of Unknown Function

2007 ◽  
Vol 73 (6) ◽  
pp. 1952-1960 ◽  
Author(s):  
A. Schlüter ◽  
R. Szczepanowski ◽  
N. Kurz ◽  
S. Schneiker ◽  
I. Krahn ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Unknown Function ◽  
Municipal Wastewater ◽  
Ralstonia Eutropha ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Macrolide Resistance ◽  
Municipal Wastewater Treatment ◽  
Erythromycin Resistance ◽  
Modification System

ABSTRACT The erythromycin resistance plasmid pRSB105 was previously isolated from an activated sludge bacterial community of a municipal wastewater treatment plant. Compilation of the complete pRSB105 nucleotide sequence revealed that the plasmid is 57,137 bp in size and has a mean G+C content of 56.66 mol%. The pRSB105 backbone is composed of two different replication and/or partitioning modules and a functional mobilization region encoding the mobilization genes mobCDE and mobBA. The first replicon (Rep1) is nearly identical to the corresponding replication module of the multiresistance plasmid pRSB101 isolated from an unknown activated sludge bacterium. Accordingly, pRSB101 and pRSB105 are sister plasmids belonging to a new plasmid family. The second replicon (Rep2) of pRSB105 was classified as a member of the IncP-6 group. While Rep1 confers replication ability only in γ-proteobacteria, Rep2 extents the host range of the plasmid since it is also functional in the β-proteobacterium Ralstonia eutropha. Plasmid pRSB105 harbors the macrolide resistance genes mel and mph, encoding, respectively, a predicted ABC-type efflux permease and a macrolide-2′-phosphotransferase. Erythromycin resistance is mainly attributed to mel, whereas mph contributes to erythromycin resistance to a lesser extent. The second resistance region, represented by an integron-containing Tn402-like element, includes a β-lactam (oxa10) and a trimethoprim (dfrB2) resistance gene cassette. In addition to antibiotic resistance modules, pRSB105 encodes a functional restriction/modification system and two nonresistance regions of unknown function. The presence of different mobile genetic elements that flank resistance and nonresistance modules on pRSB105 indicates that these elements were involved in acquisition of accessory plasmid modules. Comparative genomics of pRSB105 and related plasmids elucidated that pRSB105 evolved by integration of distinct modules from different plasmid sources, including Pseudomonas aeruginosa plasmids, and thus represents a mosaic plasmid.

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