Development of a model for activated sludge aeration systems: linking air supply, distribution, and demand

2016 ◽  
Vol 75 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Oliver Schraa ◽  
Leiv Rieger ◽  
Jens Alex

During the design of a water resource recovery facility, it is becoming industry practice to use simulation software to assist with process design. Aeration is one of the key components of the activated sludge process, and is one of the most important aspects of modelling wastewater treatment systems. However, aeration systems are typically not modelled in detail in most wastewater treatment process modelling studies. A comprehensive dynamic aeration system model has been developed that captures both air supply and demand. The model includes sub-models for blowers, pipes, fittings, and valves. An extended diffuser model predicts both oxygen transfer efficiency within an aeration basin and pressure drop across the diffusers. The aeration system model allows engineers to analyse aeration systems as a whole to determine biological air requirements, blower performance, air distribution, control valve impacts, controller design and tuning, and energy costs. This enables engineers to trouble-shoot the entire aeration system including process, equipment and controls. It also allows much more realistic design of these highly complex systems.

RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41727-41737 ◽  
Author(s):  
Hebin Liang ◽  
Dongdong Ye ◽  
Lixin Luo

Activated sludge is essential for the biological wastewater treatment process and the identification of active microbes enlarges awareness of their ecological functions in this system.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9325
Author(s):  
Katarzyna Jaromin-Gleń ◽  
Roman Babko ◽  
Tatiana Kuzmina ◽  
Yaroslav Danko ◽  
Grzegorz Łagód ◽  
...  

Reduction of the greenhouse effect is primarily associated with the reduction of greenhouse gas (GHG) emissions. Carbon dioxide (CO2) is one of the gases that increases the greenhouse effect - it is responsible for about half of the greenhouse effect. Significant sources of CO2 are wastewater treatment plants (WWTPs) and waste management, with about 3% contribution to global emissions. CO2 is produced mainly in the aerobic stage of wastewater purification and is a consequence of activated sludge activity. Although the roles of activated sludge components in the purification process have been studied quite well, their quantitative contribution to CO2 emissions is still unknown. The emission of CO2 caused by prokaryotes and eukaryotes over the course of a year (taking into account subsequent seasons) in model sequencing batch reactors (SBR) is presented in this study. In this work, for the first time, we aimed to quantify this contribution of eukaryotic organisms to total CO2 emissions during the WWTP process. It is of the order of several or more ppm. The contribution of CO2 produced by different components of activated sludge in WWTPs can improve estimation of the emissions of GHGs in this area of human activity.


2015 ◽  
Vol 809-810 ◽  
pp. 1573-1578
Author(s):  
Casen Panaitescu ◽  
Monica Emanuela Stoica ◽  
Ciner Fehiman

Manufacture of wastewater treatment technologies is an important issue due to the complexity of design parameters and performance. Biological wastewater treatment is a process in which the intensity of oxygen transfer into water is an issue that has been extensively studied but yet insufficiently resolved. The present paper aims to describe an aeration system developed by the author in the laboratory by means of non-conventional technologies, and subsequently implemented in refinery wastewater treatment plants. The aeration system takes the form of modules, which are equipped with a new type of membrane. The analysis of the system performance revealed that oxygen transfer was 62%, specific adsorption of oxygen was 37 % and the specific oxygen transfer was 7%/m. The advantages of this new system are as follows: compared to existing technologies there is a higher rate of oxygen transfer into water; longer life; there are no dead zones in the basin as a result of their location; possibility of operating on separate sections.


2001 ◽  
Vol 44 (9) ◽  
pp. 189-196 ◽  
Author(s):  
P. Hardy ◽  
J.E. Burgess ◽  
S. Morton ◽  
R.M. Stuetz

Lab-scale tests were used to determine the amount of H2S that can be treated using a range of different activated sludges. Static vessels were used to study the effects of different H2S concentrations (5, 25, 50 and 75 ppm). The data indicated that odour control may be carried out using certain types of sludge, but sludge type, e.g. carbonaceous, nitrifying, with or without coagulant, affects removal efficiency. The presence of the biomass resulted in greater H2S removal than the use of wet scrubbing and the adverse effects on mixed liquor were negligible. A pilot plant was used to study the removal efficiencies of activated sludge diffusion using a typical wastewater treatment plant H2S concentration and investigated the effects that the diffusion of H2S had on the process performance. Results indicated that the levels of H2S produced by other unit processes on a wastewater treatment site (approximately 5 ppm) can be treated using activated sludge diffusion without compromising the performance of the wastewater treatment process. The only effects on the activated sludge plant observed were: (1) nitrification was interrupted briefly as H2S diffusion commenced and (2) the species' diversity in the sludge decreased.


Sign in / Sign up

Export Citation Format

Share Document