best available technologies for manure treatment - Baltic Green Belt

Best Available Technologies for manure treatment baltic sea 2020
Best Available Technologies for manure treatment baltic sea 2020
ANNEX E: TABLES WITH SHORT DESPRIPTION OF LIVESTOCK MANURE TREATMENT TECHNOLOGIES
Best Available Techniques for manure treatment - for intensive rearing of pigs in Baltic Sea Region EU Member States Technical Report "Best Practice Manure Handling, Phase 2"
Ref No. 16 Flotation
Brief description
Description of the effect on leaching (positive or negative) of N
and P
Flotation is used extensively in food industry especially for the treatment of process
wastewater. By flotation, suspended material can be separated from the liquid phase and
concentrated in a sludge phase, skimmed and handled separately. By flotation, water
saturated with air under pressure is brought to the bottom of the flotation tank and
releases microscopic bubbles to the wastewater or manure to be treated. In contrast to
sedimentation, where heavy particles precipitated in a liquid, you get in a flotation
formed large light particles brought to the surface of very fine small bubbles, which sits
on the suspended material. The suspended material can be scraped off the surface with a
mechanical scraper and forms flotation sludge. Virtually all suspended material in the
liquid can be removed by this process.
By flotation a very high proportion of ammonia in the liquid is discharged with
the air, while the suspended material floated. It is therefore necessary to make a
collection of exhaust air from flotation if the method should be recommended.
This should be done to prevent the ammonia to escape with the exhaust air,
which subsequently will lead to a deposition of ammonia.
A Danish company has applied the flotation in combination with ozone dosing for
treatment of manure. Furthermore, there is installed a flotation plant to treat degassed
biomass on a single biogas plants in Denmark. Flotation has been used for treatment of
manure on pig farms in USA.
Flotation is thus a process, which can further purify the liquid fraction after a mechanical
separation and a flocculation process. Flotation is often used in combination with
chemical flocculation.
Innovation stage
Investment price,
Basic Variable
Operational
costs,
per
tonnes
per kg
saved N or
P leaching
Complexity of implementation
Research
Pilot
Practice
Major references
No data. However, a plant in Holland, which used flotation in
addition to flocculation, drum belt separation, reverse osmosis,
and demineralisation, claimed the operational costs for all
processes were at a level of 5 per ton slurry.
Condition for leaching reduction
effect
Certainty of information
No data.
High – typically the technology is part of a high-tech
livestock manure management treatment plant.
Foged, 2009 Scenarios II to V
Prices Low
Effect on leaching High
54
Page 55
54