How much artificial aeration methods, such as constructing cascades or weirs, using mechanical aerators, floated plants, or pumping out and discharging again the water, can increase the rearation rate (Ka) of rivers? Is there any practical case study pointing to this fact?
I know that this depends on various parameters, and I dont need the aeration potential of these methods. I am really looking forward to any literature, case study or report that directly shows Ka is changed from X to Y in rivers.
I suggest you have a look at the book Aeration: Principles and Practice (CRC Press). Papers from John Gulliver (University of Minnesota), for example, might also help you.
I think as long as the Dissolved Oxygen is higher than 5 mg/liter the river system is healthy. 8 mg/l is the most excellent rate. Thus you can calculate the Ka by knowing the current DO level and how it can be reached to 8 mg/l in a matter of volume.
Dear Khaled
For calculating Ka, it is necessary to sketch the concentration of DO against time before and after the cascade. Therefore, if there is any literature that points to this fact might be helpful. Besides, I guess there are some practices in rivers around world that use these methods. But I wonder is there any data!!!
Hi!
What kind of rivers are interesting for you? You mean to mountain or lowland rivers?
The aerations problems is only in rivers, which have very high level of organic pollution. You have this problem or any other problems.
Your problems are local or they concerned the river on the whole?
The study area starts from mountanious and ends in lowlands. The problem is in the latter where its velocity reduces. In upstream DO level is good but in downstream, it comes below 2 mg/L.
I wonder if I use aeration in this area, how much DO will be increased?
I found no evidence in other rivers to use this approach and present aeration rate.
kLa is a very important design parameter for wastewater aeration. I have studied the energetic optimization and adaptive control of the dissolved oxygen concentration in aerobic fermenters by numerical simulation. The parameters of the usual KLa correlation were estimated on-line and at real-time through the recursive least squares algorithm with forgetting factor, most effectively when a small sinusoidal disturbance was imposed to the manipulated variables (stirring rate and/or air flow). The power dissipated by agitation was accessed by a torque meter (pilot plant). This investigation was reported at (MSc Thesis):
Thesis Controlo do Oxigénio Dissolvido em Fermentadores para Minimi...
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