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.

The Operating Characteristics of Orbal Oxidation Ditch Process under Low Dissolved Oxygen

2013 ◽  
Vol 328 ◽  
pp. 297-303
Author(s):  
Si Mei Zhang ◽  
Lu Liu ◽  
Shu Heng Hu
Keyword(s):  
Dissolved Oxygen ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxidation Ditch ◽  
Operating Characteristics ◽  
Low Dissolved Oxygen ◽  
N Removal ◽  
Orbal Oxidation Ditch

Orbal oxidation ditch is widely used in urban sewage treatment system ,Oxygen consumption level is an important index to measure process operating characteristic, discuss the operation mode of Oxidation ditch under low dissolved oxygen concentration condition is the main link of Sewage plants energy saving operation. Through the adjustment of chongqing TongLiang sewage treatment plant Orbal oxidation ditch aerations equipment operation parameters, the operating power reduced 7.5 kW, the removal rate of TN increased from 19% to more than 50%,and COD, BOD5, TP, NH3 - N removal rate was not affected, the Water meet the design requirements.

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.

A Research on the Activated Sludge Acclimation

2012 ◽  
Vol 610-613 ◽  
pp. 1509-1512
Author(s):  
Xiao Nan Zhang ◽  
Shi Qiang Ding ◽  
Ji Run Xu
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Influence Factors ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Acclimated Activated Sludge

By a circular operation of anaerobic mixing - aerobic aeration – sediment drain, a sludge with low activation obtained from a common sewage treatment plant is acclimated in laboratory. The acclimation is performed with simulated sewage and composed of three periods. In the every period, the sewage concentration is successively increased, the removal percentage of COD, NH4+-N and TP are measured, when the removal is stable, the period is transformed to next one. The outside and construction characteristics of the activated sludge are observed and the protozoon is examined. Meanwhile, some influence factors such as temperature, dissolved oxygen and pH are analyzed. The experiments show that the acclimated activated sludge is able to remove the COD, NH4+-N and TP effectively under a suitable but easy-to-be obtained conditions.

Automation and Optimisation of Centrifuge Sludge Dewatering

1989 ◽  
Vol 21 (10-11) ◽  
pp. 1319-1324 ◽  
Author(s):  
Gunter Schrank ◽  
Clive Murren
Keyword(s):  
Continuous Measurement ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Effective Control ◽  
Excess Sludge ◽  
Chemical Additives ◽  
Sludge Dewatering ◽  
Sludge Thickening ◽  
Very High

The dehydration of sewage treatment plant sludges has become one of the major problems in the treatment of waste Water. Very high costs, especially those of flocculation additives, increasingly call for optimisation of this phase of the process. Taking the dewatering of sludge by centrifugation as an example, two different approaches can be considered: mechanical excess sludge thickening without the use of additives and the dehydration of sewage sludge with use of chemical additives. A prerequisite of any automation is the reliable acquisition of data of the parameters required for control. Continuous measurement of the concentration of suspended solids in the sludge that is to be dewatered, of sludge flow and of the turbidity of the clear phase (centrate) leaving the centrifuge, make it possible to design several methods of effective control.

Start-Up of the Anaerobic Fluidized Bed

2014 ◽  
Vol 522-524 ◽  
pp. 695-698
Author(s):  
Xiao Ming Sun ◽  
Jing Yang Liu ◽  
Qi Qiao
Keyword(s):  
Removal Rate ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Organic Load ◽  
Municipal Sewage ◽  
Organic Loading Rate ◽  
Start Up ◽  
Cod Removal Rate ◽  
Anaerobic Digester Sludge

Inoculated with anaerobic digester sludge of municipal sewage treatment plant, using the method of organic load increasing, anaerobic fluidized beds was started-up after 82 days. At organic loading rate of 5kgCOD/m3·d, the COD removal rate was 81%. The structure of this biofilm is good and propitious to further domestication.

scholarly journals Biogas Production From Co Digestion of Automotive Wastewater And Synthetic Wastewater in Anaerobic Reactor

2020 ◽  
Vol 5 (5) ◽  
pp. 1954-1959
Author(s):  
Uzana Ismail ◽  
Zaifah Che Wil ◽  
Syazwani Idrus
Keyword(s):  
Ph Value ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Cod Removal ◽  
Synthetic Wastewater ◽  
Organic Loading Rate ◽  
Anaerobic Reactor ◽  
Mechanical Agitator

The purpose of this study is to investigate the biogas potential from automotive wastewater codigested with Synthetic wastewater treated in anaerobic reactor. This experiment was run by continuously mixed with mechanical Agitator stirring tank reactor and were established under mesophilic condition at temperature of 38°C. The source of inoculum used in this study were obtained from sewage treatment plant. The experiment was analyzed based on COD removal and biogas production in relation with parameters such as pH, organic loading rate, alkalinity and effect of Zinc and Copper which runs on automotive wastewater. From the result obtains, the reactor condition was unstable during mono digestion of automotive wastewater which aligned with indication of decreasing biogas production, low pH value below 6.0 and low COD removal with value of 63.4%. However, the reactors become stable during co digestion of automotive wastewater with Synthetic wastewater with 0.12 g/L/d OLR and with highest methane production 0.140 L of CH4 / day. The findings illustrate the nutrient available in Synthetic wastewater could enhance the synergistic effect in co digestion with automotive wastewater and therefore resulted with the highest COD removal rates.

On Control Regulation of Urban Initial Period Rainwater Pollution

2011 ◽  
Vol 183-185 ◽  
pp. 705-709
Author(s):  
Xue Yi You ◽  
Jing Li ◽  
Yan Wei Li ◽  
Min Ji ◽  
Xiu Duo Wang ◽  
...  
Keyword(s):  
Initial Period ◽  
Sewage Treatment ◽  
Great Influence ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Control Measures ◽  
Effective Control ◽  
Control Regulation ◽  
Tianjin City

The initial period rainwater has a great influence on the quality of surface water in Tianjin city. To reducing the initial period rainwater pollution, the effective control measures must be taken for initial period rainwater. A comprehensive operation regulation by using the surplus capacity of sewage treatment plant, reservoirs and rivers is proposed and studied in this paper. The order of initial period rainwater storage is firstly in sewage treatment plant, then in reservoirs and finally drainage to rivers. By carefully arranging the intercepted amount of every storage stage, the pollution of initial period rainfall in an example Tianjin area is shown to be effectively solved.

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