I am a young Process/Environmental Engineer, recently started working for a company that designs, builds and commissions WWTPs. Here is the info :
On one of the WWTPs we built, there is a problem with sludge. WWTP is processing wastewater from pharmaceutical industry and it consists of: equalisation/neutralisation tank, coagulation addition, pipe flocculator and lamella plate clarification. Sludge from the clarification is pumped to a sludge thickening tank. After enough sludge of about 2%DS is collected, the sludge is being sent to a treatment with sludge filter bags (with addition of K-PE).
The issue is that sludge thickening is not doing well, with only 0.2%DS of the sample from the bottom of the sludge thickener. I advised the operator to recirculate the sludge from Lamella plate separator, back to the pipe flocculator, and to monitor the sludge consistence, assuming that this should improve the settleability of the sludge. Am I right?
I am also open to a suggestions on what could cause this situation.
P.S. On several pictures of the lamella separator in process there can be seen bubbles. I am not sure if this is due to a denitrification, or there is another explanation, but I guess this can be one of the reasons why solids tend to float, instead of settling.
Sorry for the long writing. Thank you in advance for your suggestions or advises.
On one of the WWTPs we built, there is a problem with sludge. WWTP is processing wastewater from pharmaceutical industry and it consists of: equalisation/neutralisation tank, coagulation addition, pipe flocculator and lamella plate clarification. Sludge from the clarification is pumped to a sludge thickening tank. After enough sludge of about 2%DS is collected, the sludge is being sent to a treatment with sludge filter bags (with addition of K-PE).
The issue is that sludge thickening is not doing well, with only 0.2%DS of the sample from the bottom of the sludge thickener. I advised the operator to recirculate the sludge from Lamella plate separator, back to the pipe flocculator, and to monitor the sludge consistence, assuming that this should improve the settleability of the sludge. Am I right?
I am also open to a suggestions on what could cause this situation.
P.S. On several pictures of the lamella separator in process there can be seen bubbles. I am not sure if this is due to a denitrification, or there is another explanation, but I guess this can be one of the reasons why solids tend to float, instead of settling.
Sorry for the long writing. Thank you in advance for your suggestions or advises.