Efficiency? - Activated Sludge used for wastewater from a building

[Linn]

Wastewater from the building contains 30-40 mg/l of BOD. Its existing wastewater treatment unit is activated sludge, consists of flow equalizer, aeration and sedimentation.

Some times ago, the previous consultant had problem with sludge in the aeration tank - It became solid and had a smell.

At the moment, sludge has been kept in the areation tank for more than 6 months. The problem is BOD of wastewater in the sedimentation tank is higher than BOD of the whole system's influent. Indeed, the BOD level measured is higher than COD - which is not possible.

What I wonder is that the activated sludge may not be suitable for this kind of effluent. However, as the system is the existing unit, how should I utilize or deal with it efficiently.

Any suggestion is welcome. Thank you.

Linn

 

[BobPE]

A sludge retention time of 6 months is a bad thing. of course it would smell and turn solid. See if you can find sludge wasting records, maybe a local hauler that used to take the sludge out of the system back when someone knew how to run it. Chances are, the practice of sludge hauling was eliminated by the accounting department because they didn't understand what the cost was for. I have see that all to often when called in to look at systems that are broken.

BobPE

 

[waterexpert]

Evidence here of the biggest drawback of activated sludge-it does require a certain level of knowledge to operate.It might be an idea to send the operators on a refresher course in activated sludge plant operation. If indeed there are operators, and they have been trained.

I've seen plants operated at up to 20,000 ppm MLSS, but never one which had completely solidified. Congratulations!

 

[mmo]

it would be fine to know a little more about the real influent to the tratment plant.Maybe double check the analysis with other laboratory is a good begining. The sludge to turn solid is quite difficult if the aeration has been working all the time, but I feel this is not the important thing now, you should begin knowing exaclty what is cominginto the plant. Look for concealed connections.rgds
mmo