A study of the relationship between the mixed liquor fauna and plant performance for a variety of activated sludge sewage treatment works

1984 ◽  
Vol 18 (3) ◽  
pp. 281-287 ◽  
Author(s):  
J.E.P. Poole
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Plant Performance ◽  
Mixed Liquor ◽  
The Relationship

Solids routing in an activated sludge process during hydraulic overloads

1996 ◽  
Vol 34 (3-4) ◽  
pp. 9-16 ◽  
Author(s):  
Youngchul Kim ◽  
Wesley O. Pipes
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Quantitative Description ◽  
Settling Tank ◽  
Plant Performance ◽  
Activated Sludge Process ◽  
Mixed Liquor ◽  
Solids Concentration ◽  
Storm Flow ◽  
The Individual

In order to provide a quantitative description of solids wash-out from the settling tanks of an activated sludge process, a method for “routing” of the suspended solids through the settling tanks was developed. The objective was to develop a method which can be used to predict the mixed liquor suspended solids concentration (X) and the sludge blanket depth (SBD) in the clarifiers during transient hydraulic overloads. There were 27 individual hydraulic overloading events encountered during 31 months of study. The solids routing and the SBD prediction were performed for the individual storm flow events by using settling tank operating data. The results of solids routing analysis were found to be satisfactory. The mixed liquor solids concentration can be predicted within ± 10%. The application of a solids storage relationship developed for the settling tanks was found to be useful for describing the dynamic behavior of the SBD during transient hydraulic overloads. The solids wash-out predictions for rainstorm periods corresponded with the plant performance. Operational procedures for avoiding solids wash-out are also discussed.

Effects of mixed liquor ozonation in an activated sludge system for sewage treatment

2017 ◽  
Vol 70 ◽  
pp. 150-156
Author(s):  
S. Pesante ◽  
G. Morales ◽  
C. Baeza ◽  
G. Gómez ◽  
G. Vidal
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Mixed Liquor ◽  
Activated Sludge System

A study on filamentous bacteria in activated sludge process of sewage treatment plant in Dubai, United Arab Emirates

2009 ◽  
Vol 4 (2) ◽  
Author(s):  
S. M. Faheem ◽  
M. A. Khan
Keyword(s):  
Activated Sludge ◽  
United Arab Emirates ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Differential Staining ◽  
Type I ◽  
Activated Sludge Process ◽  
Filamentous Bacteria ◽  
Mixed Liquor

A study was conducted on filamentous bacteria implicated in bulking and foaming problems in activated sludge process of sewage treatment plant in Dubai, United Arab Emirates over a period of six months. To determine morphological characteristics of diverse filaments, foam and mixed liquor samples were collected and studied using various simple and differential staining techniques. Fluorescent in situ hybridization analysis was carried out in mixed liquor samples with nocardioform group specific probes using VIT kit (Vermicon Identification Technology, Vermicon, Munich). The dominant filamentous bacteria identified from mixed liquor and foam samples included: A long branched form of Gram varibale nocardioform actinomycetes species, Thiothrix, Eikelboom Type 021N, Sphaerotilus natans, Beggiatoa and Nostocoida limicola type I. Occasionally attached growth forms of Eikelboom type 0041/0675 like filaments were observed in mixed liquor and foam samples especially during warm weather. All filamentous bacteria identified were found in both the samples throughout the study period. FISH analysis successfully identified filamentous and non-filamentous morphotypes of nocardioform group members. It is concluded that specific filamentous bacterial population in mixed liquor and foaming activated sludge was constant and not dependent on variable wastewater characteristics.

scholarly journals The Shock Effect of Inorganic Suspended Solids in Surface Runoff on Wastewater Treatment Plant Performance

2019 ◽  
Vol 16 (3) ◽  
pp. 453 ◽  
Author(s):  
Li He ◽  
Tao Tan ◽  
Zhixi Gao ◽  
Leilei Fan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Surface Runoff ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Suspended Solid ◽  
Plant Performance ◽  
Normal Operation ◽  
Mixed Liquor

Previous studies on the water quality of surface runoff often focused on the chemical oxygen demand (COD), nitrogen, phosphorus, and total suspended solid (TSS), but little is known in terms of the inorganic suspended solids (ISS). This research investigated the effects of ISS carried by surface runoff on the treatment efficiency of the pretreatment facilities and the ratio of mixed liquor volatile suspended solid to mixed liquor suspended solid (MLVSS/MLSS) of the activated sludge in a wastewater treatment plant (WWTP) with the anaerobic-anoxic-oxic (AAO) process in Chongqing city, China. The results showed that the surface runoff had a long-lasting impact on the grit removal capacity of the grit chamber, affecting the normal operation after the rainfall. In contrast, the primary sedimentation tank showed strong impact resistance with higher removal rates of COD, TSS, and ISS. Nonetheless, the primary settling tank aggravates the removal of organic carbon in sewage during rainfall, having a negative impact on subsequent biological treatment. The ISS in the surface runoff could increase the sludge concentration and decrease the MLVSS/MLSS ratio. After repeated surface runoff impact, the MLVSS/MLSS ratio in the activated sludge would drop below even 0.3, interrupting the normal operation of WWTP.

Particle Size Distribution to the Final Effluent Quality - Based on Turbidity

2013 ◽  
Vol 838-841 ◽  
pp. 1651-1654
Author(s):  
Meng Meng Yin ◽  
He Li Wang ◽  
Chao Yang
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Activated Sludge ◽  
Size Distribution ◽  
Activated Sludge Process ◽  
Effluent Quality ◽  
Mixed Liquor ◽  
Relationship Of ◽  
The Relationship ◽  
Final Effluent

This paper studies the particle size distribution (PSD) and final effluent quality in the activated sludge process. The PSD of final effluent and mixed liquor were determined, and it was found that the settlement in the process can remove particles between 100μm and 200μm easily, while difficult to remove the particles between 13.5μm to 65μm, which was in the supracolloidal (1-100μm) range and could cause problem at higher flows. The final effluent quality was measured by turbidity. The relationship of PSD-10 with turbidity, was analysed and the formed links were paired. Therefore, the PSD can be linked with final effluent quality and can be expected to use as an index to evaluate the final effluent quality future.

Pyridine Degradation by Suspensions and Biofilms of Achromobacter pulmonis PNOS and Burkholderia dolosa BOS Strains Isolated from Activated Sludge of Sewage Treatment Plants

2020 ◽  
Vol 36 (2) ◽  
pp. 86-98
Author(s):  
A.A. Sergeeva ◽  
G.V. Ovechkina ◽  
A.Yu. Maksimov
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Local Treatment ◽  
Carbon Sources ◽  
Mining Institute ◽  
Bacterial Strains ◽  
Federal Research ◽  
Registration Number ◽  
Treatment Facilities ◽  
Pyridine Degradation

Bacterial strains capable of degradation of 0.8-15.8 g/1 pyridine hydrochloride have been isolated from activated sludge of municipal biological treatment plants in Perm (BOS) and local treatment facilities of the LUKOIL-Permnefteorgsintez enterprise (PNOS). The strains were identified as Achromobacter pulmonis and Burkholderia dolosa. The optimal pyridine concentration for the growth of the isolated strains was 4.0 g/1. The pyridine degradation during the A. pulmonis PNOS and B. dolosa BOS cultivation on a medium with ammonium chloride and glucose and without additional nitrogen or carbon sources was studied. It was shown that the strains are able to accumulate biomass in a medium with pyridine as the sole carbon and nitrogen source; the addition of glucose to the medium (1 g/L) accelerated the pyridine degradation by A. pulmonis PNOS, but inhibited the process carried out by B. dolosa BOS. B. dolosa BOS and A. pulmonis PNOS biofilms efficiently utilized pyridine during growth on basalt and carbon fibers; the highest rate of pyridine utilization (1.8 g /(L day)) was observed in A. pulmonis PNOS biofilms on basalt fibers. pyridine, biodegradation, activated sludge, biofilms, Achromobacter pulmonis, Burkholderia dolosa The authors grateful to Dr. I.I. Tchaikovsky, Head of the Laboratory of Geology of Mineral Deposits of the Mining Institute, a branch of the Perm Federal Research Center, for help with electron microscopy of the samples. This work was carried out as part of a state assignment on the topic « Study of the Functional and Species Diversity of Microorganisms Useful for Ecocenoses and Human Practical Activity», registration number R&D AAAA-A19-119112290008-4.

Activated Sludge Exocellular Material Extraction Methods and Problems

1974 ◽  
Vol 9 (1) ◽  
pp. 250-261
Author(s):  
D.F. Carr ◽  
J. Ganczarczyk
Keyword(s):  
Activated Sludge ◽  
High Speed ◽  
Sewage Treatment ◽  
Dry Weight ◽  
Extraction Methods ◽  
Volatile Material ◽  
Bacterial Cultures ◽  
Volatile Solids ◽  
Pure Bacterial Cultures ◽  
Material Extraction

Abstract Activated sludge samples from two Toronto sewage treatment plants were subjected to the extraction of exocellular material by means of 9 different methods suggested for this purpose. Some of those methods, originally developed for pure bacterial cultures, were modified for the application to activated sludge. The amount of exocellular material obtained varied for Lakeview sludges from 0.4 to 3.2% of their dry volatile solids, and for Humber sludges from 0.3 to 5.3%. It has been found that extractions by the use of sulphuric acid, high-speed centrifugation and sodium hydroxide, were not suitable for the studied material. Especially surprising was the ineffectiveness of high-speed centrifugation to yield any measurable amounts of extract. The boiling water extraction is recommended for further studies on activated sludge exocellular material. The material extracted from activated sludge is very complex in nature. Generally more polysaccharide than protein was extracted, but the remaining volatile material may form up to 70% of the dry weight.

Control of Bulking in an Extended Aeration Sewage Treatment Plant

1972 ◽  
Vol 7 (1) ◽  
pp. 13-20
Author(s):  
D.D.P. Cane ◽  
G.J. Farguhar
Keyword(s):  
Dissolved Oxygen ◽  
Control Measure ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Effective Control ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Mixed Liquor ◽  
Air Supply

Abstract A case of filamentous activated sludge bulking was investigated at an extended aeration plant treating wastes from a highway service centre. The purpose of the study was to find an effective control measure for the bulking and, if possible, to determine the cause of the bulking condition. Experiments were conducted to determine the effects upon bulking of: (a) a controlled copper dosage to the mixed liquor, (b) variations in the organic loading rate, and (c) maintenance of high and low dissolved oxygen concentrations in the mixed liquor. The microorganism responsible for the bulking condition was tentatively identified as Sphaerotilus natans. Extensive growths of these bacteria occurred in the sludge when the mixed liquor dissolved oxygen concentration dropped below 0.5 mg/1. Such dissolved oxygen levels had frequently occurred at this plant due to the use of timed aeration cycles and the use of insufficient air supply during peak loading periods. Variations in organic loading rates were found to have no adverse effect on sludge settleability. When bulking was slight, the condition could be improved by increasing the dissolved oxygen level to 1.5 mg/1, or more. The rate at which the filamentous growths could be eliminated from a highly filamentous sludge by increased aeration was very slow, but could be greatly increased by the simultaneous feeding of copper to the mixed liquor at a dosage rate of 1.0 mg/1, based on the raw sewage flows.

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