- A municipal waste water treatment plant in one Baltic town continuously had problems with the fat, oil and grease (FOG) accumulation in the sewer lines, lift stations and waste water treatment plant, since the start up of a local meat processing facility. The highly polluted waste water directly impacted the treatment plant in the following ways:
- Increased grease accumulation in sewer lines and lift stations;
- Poor sedimentation of the active sludge in the secondary clarifiers;
- High sludge volume index (SVI- -200);
- Poorer sludge dewatering results: lower solids content in dewatered sludge;
- Greasy sludge blanket on the top of the treatment plant (see pictures).
The meat factory also faced the increased main-tenance for (FOG) accumulation in grease traps, and sewer lines clogging plus increased fees for the discharge of highly contaminated waste water to the municipal sewer lines.
Brief description of waste water treatment system of the meat factory and the town
- The meat factor)' is discharging app. 200 m3 per day of waste water to the municipal sewer lines.
- The wastewater is treated in 3 grease traps and the sedimentation-collection tank in a row at the meat factory.
- After the primary treatment the waste water is discharged to the municipal sewer lines.
- The municipal sewage system and waste water treatment plant consists of: couple kilometers of sewer line from factory to WWTP, lift station, primary sedimentation tank> aeration tanks> secondary clarifiers and sludge dewatering department.
- Total daily waste water flow to municipal WWTP is from 5000 to 8000 m3.
For the solution of grease accumulation problems GREASOLUX cartridges were proposed. They were placed in the sewer system of the meat factor}'. GREASOLUX cartridges are rugged, submersible cylinders, containing highly concentrated environmentally-safe, naturally occurring, microbes and fermentation media, that slowly dissolve and are released to the waste water. The main tasks of using GREASOLUX are:
- Reduce total contamination of the meat factory waste water.
- Reduce grease accumulation in the sewer lines, grease trap and lift station.
- Reduce grease concentration in the active sludge, increase the overall performance of waste water treatment and sludge dewatering processes in the municipal waste water treatment plant.
- The GREASOLUX application commenced in the middle of June 2012.
- 4 units of GREASOLUX-M were used in total.
- Three GREASOLUX-M cartridges were submersed in grease traps (single cartridge to ever)' grease trap) and one GREASOLUX-M unit was submersed to the sedimentation-collection tank in the area of meat manufacturing factory.
- The GREASOLUX cartridges are then replaced after approximately 2 months
After three months of GREASOLUX use the following results were observed: At the meat factory:
- Using of GREASOLUX helped to avoid blockages of pipes and reduce grease accumulation in the grease traps> equalization tank> and lift station.
- Also GREASOLUX helped to decrease the contamination of the wastewater discharged to the municipal sewer system.
At the municipal waste water treatment plant:
- The grease degrading microorganisms successfully inhabited the aeration basins of the treatment plant. The present population of the active sludge microorganisms was expanded with the special, grease degrading microorganisms - the efficiency of grease biodegradation was considerably increased.
- After a few months of GREASOLUX use the blanket of the greasy sludge disappeared from the surface of the aeration zone and sedimentation tank of the wastewater treatment plant.
- The sludge sedimentation conditions in the municipal waste water treatment plant improved -the sludge volume index dropped down. The use of GREASOLUX eliminated the washouts of active sludge from the secondary clarifier, determined by the poor sedimentation conditions of the active sludge.