The influence of currents on circular secondary clarifier performance and design

1996 ◽  
Vol 34 (3-4) ◽  
pp. 405-412 ◽  
Author(s):  
Andrea Deininger ◽  
Frank W. Günthert ◽  
Peter A. Wilderer
Keyword(s):  
Wastewater Treatment ◽  
Density Currents ◽  
Clear Water ◽  
Performance Measurements ◽  
Design Procedures ◽  
Secondary Clarifier ◽  
Current Design ◽  
Hydraulic Load ◽  
Novel Design ◽  
Wastewater Treatment Systems

Density currents in the deeper zones of clarifiers and currents in the clear water zone have a significant influence on clarifier performance. Measurements of flow velocity profiles were conducted in full-scale horizontally flown circular secondary clarifiers. Relations between the hydraulic load and the development of density currents could be detected. Those patterns are not taken into account in current design procedures. Stationary design approaches are mainly based on the overflow rate. Novel design methods based on the dynamic behavior of flow and density distribution in clarifiers are needed in order to improve the efficacy of wastewater treatment systems.

Modelling of the Secondary Clarifier Combined with the Activated Sludge Model No. 1

1992 ◽  
Vol 25 (6) ◽  
pp. 285-300 ◽  
Author(s):  
René Dupont ◽  
Mogens Henze
Keyword(s):  
Wastewater Treatment ◽  
Simple Model ◽  
Activated Sludge ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Activated Sludge Model ◽  
Effluent Quality ◽  
Secondary Clarifier ◽  
Hydraulic Load ◽  
Flux Model

Modelling of activated sludge wastewater treatment plants is today generally based on the Activated Sludge Model No. 1 combined with a very simple model for the secondary settler. This paper describes the development of a model for the secondary clarifier based on the general flux theory for zone settling, which can be used in combination with the Activated Sludge Model to form a dynamic computer model/program for a wastewater treatment plant. In addition to the flux model, the developed model includes a simple model for predicting the contents of paniculate components in the effluent This latter model is a purely empirical model, which connects the effluent quality with the hydraulic load, suspended solids load and the nitrate load. The paper describes the model and gives some basic examples on computer simulations and verification of the model.

scholarly journals MS2 coliphage and E. coli UVB inactivation rates in optically clear water: dose, dose rate and temperature dependence

2018 ◽  
Vol 78 (10) ◽  
pp. 2228-2238 ◽  
Author(s):  
Yu Lian ◽  
Lei Mai ◽  
Nancy Cromar ◽  
Neil Buchanan ◽  
Howard Fallowfield ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Dose Rate ◽  
Ultraviolet B ◽  
Water Disinfection ◽  
High Rate ◽  
Clear Water ◽  
E Coli ◽  
Dose Rates ◽  
Log Reduction ◽  
Wastewater Treatment Systems

Abstract Natural ultraviolet irradiance disinfection is known to play a significant role in both natural wastewater treatment systems and drinking water disinfection processes, while the influence of ultraviolet B (UVB) delivering method on sunlight disinfection outcome is still unclear. This study aims to determine the effects of environmentally relevant temperatures, UVB doses (J m−2) and dose rates (W m−2) on the inactivation and log reduction values (LRVs) of the F-RNA coliphage MS2 and Escherichia coli in optically clear water. E. coli and MS2 were separately incubated and irradiated at five different doses of UVB light that delivered using six UVB dose rates. The results of the study demonstrate that the UVB dose delivering method (combination of dose rate and exposure time) influences inactivation and LRVs of E. coli and MS2 at all UVB doses investigated (up to seven-fold difference). Two phases were identified within the UVB dose rate, UVB inactivation or LRV curves for both organisms; a UVB dose rate limited inactivation phase and a dose rate saturation inactivation phase. The results contribute to a better understanding of UVB disinfection in the environment and natural wastewater treatment systems, potentially improving the design and operation of high rate algal ponds.

Optimization and Control Petroleum Refinery Wastewater Treatment Systems — Status, Trends and Needs

1989 ◽  
Vol 24 (3) ◽  
pp. 463-477
Author(s):  
Stephen G. Nutt
Keyword(s):  
Wastewater Treatment ◽  
Process Control ◽  
Petroleum Refinery ◽  
Control Strategies ◽  
Refinery Wastewater ◽  
Statistical Process ◽  
Petroleum Refinery Wastewater ◽  
Optimization And Control ◽  
And Control ◽  
Wastewater Treatment Systems

Abstract Based on discussions in workshop sessions, several recurring themes became evident with respect to the optimization and control of petroleum refinery wastewater treatment systems to achieve effective removal of toxic contaminants. It was apparent that statistical process control (SPC) techniques are finding more widespread use and have been found to be effective. However, the implementation of real-time process control strategies in petroleum refinery wastewater treatment systems is in its infancy. Considerable effort will need to be expended to demonstrate the practicality of on-line sensors, and the utility of automated process control in petroleum refinery wastewater treatment systems. This paper provides a summary of the discussions held at the workshop.

Occurrence and fate of androgens, progestogens and glucocorticoids in two swine farms with integrated wastewater treatment systems

2021 ◽  
Vol 192 ◽  
pp. 116836
Author(s):  
Jin-Na Zhang ◽  
Jun Chen ◽  
Lei Yang ◽  
Min Zhang ◽  
Li Yao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Swine Farms ◽  
Wastewater Treatment Systems

scholarly journals Phylogenomics of Rhodocyclales and its distribution in wastewater treatment systems

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhongjie Wang ◽  
Wenqing Li ◽  
Hao Li ◽  
Wei Zheng ◽  
Feng Guo
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Systems
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