Evaluation of filamentous microorganism growth factors in an industrial wastewater activated sludge system

1998 ◽  
Vol 37 (4-5) ◽  
pp. 263-270 ◽  
Author(s):  
Caroline E. Scruggs ◽  
Clifford W. Randall
Keyword(s):  
Activated Sludge ◽  
Industrial Wastewater ◽  
Filamentous Growth ◽  
Necessary Condition ◽  
Key Factors ◽  
Filamentous Microorganism ◽  
Factors Affecting ◽  
Activated Sludge System ◽  
Filamentous Microorganisms ◽  
Do Concentration

An investigation comprising four studies was undertaken to determine possible factors affecting the growth of several different types of filamentous microorganisms present in a bulking industrial wastewater activated sludge. Results from laboratory-scale continuous-flow and full-scale studies suggested that DO concentration and F:M ratio were the likely key factors affecting filamentous growth in the activated sludge. From the results of two laboratory studies isolating the effects of DO concentration and F:M ratio on filamentous growth, favorable growth ranges of DO concentration or F:M ratio were estimated for the following filaments: Microthrix parvicella, Nocardia spp., Nostocoida limicola II, and Types 0041, 1851, and 1863. Most of the bacteria causing filamentous bulking of the activated sludge were found to be filaments typically associated with low F:M, and increasing the F:M ratio appeared to cause N. limicola II to lose its competitive advantage in the activated sludge system. Type 1863, on the other hand, was found to be a low DO filament, as DO concentrations of 0.1 mg O2/l or less appeared to be a necessary condition for its filamentous growth. Though Nocardia was found to be a low F:M filament, its growth also seemed to be affected by DO concentration, as its growth was stimulated by concentrations of 1.0 mg O2/l or greater, with a near linear relationship up to at least 5 mg O2/l.

The Implementation of Bulking Control in the Design of Activated Sludge Systems

1994 ◽  
Vol 29 (7) ◽  
pp. 193-202 ◽  
Author(s):  
Jiri Wanner
Keyword(s):  
Activated Sludge ◽  
Design Procedure ◽  
Process Models ◽  
Activated Sludge Process ◽  
Operational Parameters ◽  
Technological Parameters ◽  
Factors Affecting ◽  
Filamentous Microorganisms ◽  
Biomass Retention ◽  
Selection Mechanisms

The factors affecting the growth of most common filamentous microorganisms are discussed. In a design procedure the following factors should be considered: wastewater composition (readily and slowly biodegradable substrates, inoculation), biomass retention time, actual substrate concentration in reactor, operational parameters in reactor (DO and nutrients concentration, pH, temperature) and cultivation conditions. The configurations of activated sludge process supporting the growth of floc-formers are described. As general design methods and criteria for the design of bulking control systems are not available due to the complexity of selection mechanisms, the technological parameters from successful bulking control case histories are summarized. The possibilities of mathematical activated sludge process models for design purposes are evaluated.

Non-filamentous sludge bulking caused by a deficiency of nitrogen in industrial wastewater treatment

2003 ◽  
Vol 47 (11) ◽  
pp. 289-295 ◽  
Author(s):  
Y. Peng ◽  
C. Gao ◽  
S. Wang ◽  
M. Ozaki ◽  
A. Takigawa
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Industrial Wastewater ◽  
Removal Rate ◽  
Nitrogen Deficiency ◽  
Utilization Rate ◽  
Industrial Wastewater Treatment ◽  
N Value ◽  
Sludge Bulking ◽  
Filamentous Microorganisms

Deficiency in the nutrient supply such as nitrogen usually results in activated sludge bulking and this phenomenon often takes place in the industrial wastewater treatment plants with activated sludge process. The effects of nitrogen deficiency on activated sludge bulking were studied specially in some experiments carried out in a sequencing batch reactor fed with brewing process wastewater in this paper. The experimental results showed that the sludge settled properly at an influent BOD/N value of 100/4. When the value of BOD/N was 100/3, filaments had an excessive growth at one time during the reaction process. Afterwards, the number of filamentous bacteria began to reduce and simultaneously an excessive growth of viscous Zoogloea with high percentage of moisture was observed and non-filamentous activated sludge bulking occurred. When the influent BOD/N value was 100/2, the excessive growth of filamentous microorganisms could not be observed at all times and the sludge characterization was similar to the case in which BOD/N value was 100/3. When the value of influent BOD/N was 100/0.94, more serious non-filamentous bulking occurred. Furthermore, the effects of nitrogen deficiency on the nitrogen sources and phosphorus sources utilization rate and the COD removal rate were investigated in the experiments.

scholarly journals Potential Inhibition of Filamentous Microorganisms in Sludge Bulking by Static Magnetic Field

2018 ◽  
Vol 7 (3.9) ◽  
pp. 15
Author(s):  
Nur Syamimi Zaidi ◽  
Khalida Muda ◽  
Norelyza Hussein ◽  
Mika Sillanpää
Keyword(s):  
Magnetic Field ◽  
Activated Sludge ◽  
Static Magnetic Field ◽  
Potential Approach ◽  
Biological Communities ◽  
Activated Sludge System ◽  
Sludge Bulking ◽  
Filamentous Microorganisms

In activated sludge system, the performance of the process largely depends on the balance between filamentous and floc-forming microorganisms. When the normal balance of these biological communities is disturbed, filamentous microorganisms tend to proliferate, causing various problems to the treatment performances such as sludge bulking. Various approaches have been used to control the proliferation of filamentous microorganisms. However, the approaches led to various drawbacks that eventually worsen the performances of treatment systems. Therefore, this study is aimed to investigate the potential approach using static magnetic field in inhibiting filamentous microorganisms that presence in the sludge bulking. Magnetic field of intensity 88 mT was used. Its exposure on the filamentous microorganisms was investigated in terms of filaments' characteristics such as branching, shape and filaments' location. The analysis indicated that the magnetically exposed activated sludge showed less possibility presence of the filamentous microorganisms compared to unexposed activated sludge.  

Cost-Effective Pre-Treatment of Food-Processing Industrial Wastewater

1999 ◽  
Vol 40 (7) ◽  
pp. 17-24 ◽  
Author(s):  
F. A. El-Gohary ◽  
F. A. Nasr ◽  
H. I. Aly
Keyword(s):  
Activated Sludge ◽  
Food Processing ◽  
Industrial Wastewater ◽  
Cost Effective ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Activated Sludge System ◽  
Engineering Designs ◽  
Pre Treatment ◽  
Food Processing Wastewater

Performance of laboratory-scale aerobic and anaerobic systems treating food-processing wastewater was investigated. The results obtained showed that BOD and COD of wastewater discharged from a potato-chips factory can be reduced by 86% and 82% using UASB reactor at an organic loading rate (OLR) of 2.9 kg BOD/m3·d and a hydraulic retention time (HRT) of 18 hr. Corresponding results for an activated sludge system, operated at an OLR of 8.9 kg BOD/m3·d with a HRT of 6hr were 86% and 84%, respectively. Treatment of confectionery wastewater using UASB at a HRT of 12hr and an OLR of 4.4 kg BOD/m3.d gave satisfactory results. COD and BOD removals were 92.4% and 91.5%, respectively. The use of completely activated sludge system at a HRT of 6 hr and ORL of 8.4 kg BOD/m3.d gave lower results as compared to UASB reactor. However, characteristics of the effluents produced using the two systems were in agreement with the standards regulating discharge of industrial wastewater into the sewerage system. Based on the technical and economic evaluation of the results, engineering designs were made for the selected systems.

scholarly journals Mechanism of 1,4-dioxane microbial degradation revealed by 16S rRNA and metatranscriptomic analyses

2017 ◽  
Vol 77 (1) ◽  
pp. 123-133 ◽  
Author(s):  
Xiangyu Guan ◽  
Fei Liu ◽  
Jing Wang ◽  
Caoxiang Li ◽  
Xiaoxuan Zheng
Keyword(s):  
16S Rrna ◽  
Activated Sludge ◽  
Metabolic Pathway ◽  
Industrial Wastewater ◽  
Degradation Rate ◽  
Domestic Sewage ◽  
Functional Genes ◽  
Future Studies ◽  
Human Carcinogen ◽  
Activated Sludge System

Abstract 1,4-Dioxane (dioxane), a probable human carcinogen, often exists in industrial wastewater and domestic sewage. In this study, we applied 16S rRNA and metatranscriptomic methods to analyze the dioxane biodegradation mechanism by activated sludge. Tetrahydrofuran (THF) was added as an essential co-metabolite to promote the degradation of dioxane. We found the dioxane removal ratio increased with increasing THF concentrations. When the THF concentration increased from 60.0 to 200.0 mg/L, the dioxane degradation rate was stable. Three additions of ∼60.0 mg/L THF resulted in better dioxane degradation than one addition of 200 mg/L THF. Ammonia-oxidizing and denitrifying bacteria with methane monooxygenases (MOs) and ammonia MOs played the most important roles during the degradation of dioxane. Kyoto Encyclopedia of Genes and Genomes metabolic pathway and functional genes analyses showed that the activated sludge system was complex and stable when dioxane was added. In future studies, primers should be designed to identify specific bacteria and functional MO genes, which would help reveal the function of various bacteria and their MOs during dioxane degradation.

Oxidation Ditch

2018 ◽  
Author(s):  
Gede H Cahyana
Keyword(s):  
Activated Sludge ◽  
Special Form ◽  
Oxidation Ditch ◽  
End Point ◽  
Activated Sludge System

As a part of activated sludge system, oxidation ditch has a special form like a canal without end point. Rotor is used to diffuse oxygen from air to the water.

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