Welcome to JASS!-- a Java based Activated Sludge process Simulator

How to run the simulator:

Below is a short Users Guide. You may want to print this page for reference! A complete manual will be available in the future.

1) Click on the the link "Demo" in the JASS homepage. When you see the process image just click on the START button and the simulator starts. (If you only get a grey image you have probably not enabled JAVA in your browser).

2) After the simulator has started you can select process variables to be plotted in staple diagrams (three diagrams in the upper left corner) and in an ordinary plotting diagram (upper right corner).

3) It is possible to change the characteristics of the incoming water by clicking on the button "Set Incoming". Process models are altered by clicking on the button "Constants". Further, basin volumes are changed by clicking on the button "Zone volumes".

4) Flow rates are changed by clicking on the corresponding pump symbol. Note that the pump symbol change color when the flow rate 0 is selected!

5) Sludge age and sludge concentration are shown when clicking on the button "Sludge Properties". Two modes of controlling the excess sludge is implemented; "Sludge flow control" (default): the excess sludge flow rate is then determined by the pump below the sedimentation basin, "Sludge age control": The user can the give a desired sludge age and the sludge flow rate is automatically adjusted to keep that sludge age.

6) The DO concentrations in the zones are changed by altering a value below the "Set DO ref" button, select the desired zone and then click on the "Set DO ref" button. Note that for zones where DO ref>0 some bubbles are shown! Also note that both pre and post denitrifying processes can be simulated.

A typical simulation example:

Start the simulator. Ss (soluble biodegradable matter), Snh (ammonia), and Sno (nitrite/nitrate) are default substances in the three staple diagrams. Inspect the concentration profiles. There is not much Ss available for denitrification! Add some carbon (click on the pump and try, for example, 0.15 ). Check how this affect the concentration profiles. One may also want to see how different DO concentrations affect the ammonia levels or tune the DO controllers...

Back to the JASS home page.

Department of Systems and Control, Uppsala University | URL http://www.SysCon.uu.se
Last updated: 98-10-23 by Bengt Carlsson