Biological treatment activated sludge
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Currently, the DO level in the biological system is around 0.5, SS is around 2000, and the COD of the papermaking wastewater entering the system is around 2400 (after pre-treatment); the temperature is around 39 degrees. How should I operate this system? At present, the COD of the wastewater exiting the system is around 1800. How can I improve the removal efficiency? Can it be cultivated under these conditions?
This post was last edited by Gorō Bagua Stick on 2015-8-17 at 21:25. The suspended solids level is too high; therefore, it is necessary to pass the wastewater through a primary sedimentation tank to reduce the COD to around 1000 before it enters the biochemical treatment system. The temperature can reach 39 degrees, and cooling is necessary; it usually drops after passing through the primary sedimentation tank. Biochemical system: For papermaking wastewater, the hydrolysis-acidification + aerobic activated sludge process is the most suitable. Maintain the aerobic DO above 3.0. The MLSS is controlled at 3500 mg/L.
It is better to use UASB anaerobic treatment at 39℃, followed by aerobic treatment. Keep the dissolved oxygen at around 3.0; as for SS, it can be treated using a primary sedimentation tank or air flotation
Please introduce your manufacturing process, so that I can give you more accurate advice!
A temperature of around 39 degrees does have an impact on bacterial cultivation, but this effect is limited and does not cause any fundamental changes；
Water temperatures around 35–40 degrees affect the sedimentation properties of sludge, resulting in slightly poorer performance compared to normal operating conditions. The occurrence of beneficial microorganisms such as Coelenteromon and Paramecium minor decreases, and the efficiency of activated sludge in removing pollutants slightly declines. However, this can be compensated for by reducing aeration volume (i.e., lowering DO levels) and shortening the sludge age; there is no need to worry about the cultivation of bacteria or maintaining their removal efficiency.
First, let’s lower the temperature! Improving the properties of sludge is key
The SS level is too high; it is necessary to enhance the coagulation effect during the reaction and sedimentation stage in order to reduce the amount of SS that reaches the biological treatment unit. Otherwise, this will have an adverse effect on the activated sludge and reduce its activity, which hinders the proper operation of the activated sludge tank.
I’m not sure what your water volume is? An anaerobic reactor can be added in front. Specific details can only be discussed by sending a message with the relevant parameters