Reduction of industrial sewage sludge by biological and biochemical agents
- How does it work?
- What can it be used for?
- What can it not be used for?
- Related Facilities
- Further Information
|Key words||waste, sewage, sludge, meat, dairy, slaughterhouses, encapsulation, surfactant, eco-innovation, waste water treatment plants (WWTP)|
How does it work?
|Primary objective||To reduce the large amounts of sewage sludge generated in industrial biological waste water treatment plants (WWTP).|
|Working principle|| There are different methods to reduce industrial sewage sludge, the ones that focus on reducing sludges once are generated (disintegration processes) and the ones based on the prevention principle (effect on the metabolism of the microorganisms, thus reducing biomass generation).
To date there are different commercial products to affect the metabolism of the microorganisms and reduce the sewage sludge in a WWTP:
Activated sludge is a process for treating sewage and industrial wastewaters using air and a biological floc composed of bacteria and protozoans. An agent with a biological and biochemical effect consist of an aqueous preparation with a mixture of vitamins, enzyme stabilisers and substances; once added to the activated sludge, it enwraps microorganisms and leads to the formation of compact activated sludge flocs (Fig. 1). These flocs may also incorporate small suspended mineral particles leading to an increase of floc density, thus improving the sedimentability.
Floculation proceeds as follows: 1) the aqueous preparation encapsulates the microorganisms; 2) highly selective membrane coatings are created, which works in the same way as membrane bioreactor systems; 3) auxiliary substances facilitate the mass transfer into and out of the flocs, improving degradation efficiency.
Fig. 1 Encapsulation of microorganisms by means of LODOred. (© WASTEred)
|Important process parameters||BOD, COD and pH (sewage), polymer for sludge dewatering, dose of the commercial product, temperature|
|Important product parameters|
What can it be used for?
|Operations||Encapsulation, stabilising, dewatering|
|Solutions for short comings|| Potential needs:
What can it NOT be used for?
|Operations|| The aqueous preparation, acting in a biological and biochemical level, is only suited for municipal and industrial biological WWTPs without anaerobic digestion.
LIPISOL has been tested from 2002 till 2004, only in municipal WWTP.
|Other limitations||In case of microbiological contamination of the product, due to wrong manipulation, the product efficiency could be affected.|
|Risks or hazards|| LODOred is a non-hazardous, non-toxic and fully biodegradable product. It is not classified as a dangerous preparation according to the EU standards (Commission Directive 2001/60/EC).
LIPISOL is a biodegradable product, even in anaerobic conditions (4).
|Maturity|| The aqueous preparation, marketed as LODOred-100k, has been tested since 2005. Application in industrial plants in Spain, Germany and Poland has resulted in sludge reduction ranging from 10 to 35%.
LIPISOL wast tested in two german municipal WWTPs (Neuss and Moosburg) from 2002 to 2004. Results on its technical and economical revenue can be found in the IWB- Institut für Wasser und Boden e. V. survey report (4).
|Modularity /Implementation|| LODOred is sold in containers or canisters as a liquid concentrate, to be dosed in the biological reactor. In some cases (small sewage works) it might need to be diluted in potable water previously.
It only needs a simple dosing pump to be installed and a storage reservoir. LIPISOL needs to be mixed with water. Concentration depends in each case study. Estimated dosis can be found in the IWB survey report (4), p.45.
|Consumer aspects||Lower ecological footprint processes are socially well accepted.|
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|Institutes||TTZ, Institut für Wasser und Boden|
|Companies||Bioazul, COVAP, Bioserve, Polyoxetane|
|References|| 1. http://www.wastered.eu/
4. Gutachten über einen ganzheitlichen Optimierungsansatz zur Leistungssteigerung der Abwasserbehandlung bei gleichzeitiger Kosteneinsparung am Beispiel der Kläranlage Moosburg A.D. isar, 2007. IWB- Institut für Wasser und Boden e. V.
not applicable 2.2.3 chemical, biological structure forming, other other http://www.wastered.eu/, Bioazul internal knowledge, http://www.bioserve.info WikiSysop :Template:Review document :Template:Review status