Background:

Wastewater consisting of industrial wastewater and sewage from 400 employees of the sausage producing factory.

Influent Flowrate: 350 cubic meters daily

BOD5: 1200 mg/L

COD: 2800 mg/L

FOG: 300 - 500 mg/L

The existing Wastewater treatment plant at the factory consists of the following:

1. Screen for removal of particles > 2 cm
2. Aerated grease trap
3. Balance tank
4. Screen for removal of particles > 0.6 cm
5. Dissolved Air Flotation Tank (DAF)
6. Aeration tank No. 1 (volume = 350 cubic meters)
7. Sedimentation tank No. 1
8. Aeration tank No. 2 (Volume = 150 cubic meters)
9. Sedimentation tank No. 2
10. Chlorination tank

Removal efficiency of items 1 through 4 above, in total was

BOD5 maximum of 30%, leaving 800 to 1000 mg/L at aeration tank No.1

COD maximum of 30%, leaving 2000 to 2300 mg/L at aeration tank No. 1

FOG of 80%, leaving 100 mg/L at aeration tank No. 1

The sludge treatment unit consists of:

• Sludge aerobic stabilization tank
• Thickening tank
• Mechanical thickener
• Belt filter press

Wastewater Authority Permitted Discharge Levels

BOD5: < 40 mg/L

COD: < 150 mg/L

SS: < 50 mg/L

FOG: < 10 mg/L

The Problem:

The treated effluent wastewater characteristics (outlet of Sedimentation tank No. 2) for a long time was as follows:

BOD5: 60 - 80 mg/L (out of compliance)

COD: 180 - 220 mg/L (out of compliance

Huge quantities of dead sludge started to float on the surface of the Sedimentation tanks No. 1 and No. 2.

The "sludge tests" of the mixed liquor in the Aeration tanks No. 1 and No. 2 revealed a stable (40%) sludge in the Imhoff cone. The sludge quantity has not increased in a long time.

The plant required a solution to bring the plant into compliance IN TWO WEEKS or less.

The Solution:

Alken-Murray Greek distributor, BioBest agents Sotiris Stassinos and Alina Simeonaki visited the plant and suggested immediately removing the dead sludge from the surface of the sedimentation tanks, to daily remove small amounts of sludge and treated to regenerate the very old existing sludge with new sludge from the following Alken Clear-Flo products:

First two weeks of treatment:

• 3 kg. CF 4003
• 4 kg. CF 7000
• 5 kg. CF 7008
• 4 kg. CF 7004

Second two weeks of treatment: Client ordered repeat of the above treatment after success of the first two week trial.

Followup treatment to maintain control, with dosage reduced to 4- 5 kg a week.

• 70% CF 7007
• 20% CF 7004
• 10% CF 4003

Results:

1. In less than 1 week, there was no sludge floating on the surface of the sedimentation tanks
2. The sludge tests showed sludge increasing for the first time in months
3. Microscopic analysis showed new microorganisms, not present in the past biomass
4. In less than two weeks, discharge BOD5 was 25 mg/L and COD was 120 mg/L, meeting the discharge permit and the client's goal for control
5. In three weeks, discharge BOD5 was 25 mg/L and COD was 80 mg/L
6. All analysis over a three month period, with decreasing dosages following Alken-Murray's dosage charts, showed results within the set limits.
7. Client was very pleased with the results of BioBest treatment.