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Natural conglomerate of microorganism in suspension .
The feature of bacteria to agglutinate is commonly used in the microbiologic depuration processes of waste water and is activated by polysaccharide extracells production.
Bio FlocBFC technology
Activated sludge are a suspension in water of activated biomass ( bacteria, saprophyte, protozoa, amoeba, rotifers and other microorganism) commonly in a form of floc.This sludge is the basic of activated sludge oxidation systems, the most frequent traditionaldepuration plants or waste water treatment.
The role of such a biomass ( above all available in a form of sedimentable floc made of organicmatter and colonies of bacteria they feed from) in the depuration process is to use biodegradable organic matter of the waste and decompose into smaller and less dangerous compound, which in part are used by microorganis as food and for their reproduction.
Bioflocculation is due to formation of suspended organic matter gelatinous flocs, few mm sized.
Aggregation of the flocs is probably activated by superficial electric load of organic molecules, many of them of colloidal nature and from presence of filamentous bacterial forms (Spheromixya sp., Micotrix sp.) to make up a real internal shell, the floc cohesion depend from.
Bio degradation of soluble matter, from eterogeneous aerobic bacteria population, lead to formation of CO2, H2O, NH4
+, NO2-, NO3
- and other molecules.
Bacteria are selected by global conditions, so that in environment with high concentration of protein we would find type of di Alcaligens, Flavobacterium, Bacillus, while in enrironment rich of carbohydrate we will find Pseudomonas, and at low concentration of O2 and organic matter
Nitrosomonas e Nitrobacter.
Part of decomposition occur in the activated sludge where a catalithic demolition is generated by esoenzimes on polimerich organic molecules. The need to keep both reactions requires a compromise to the internal turbulence of the waste to allow the formation of the floc but also a suitable water oxygenation to favour the aerobic metabolism
The oxidation pond is o be oxygenated as much as possible taking care not to destroy the sludge floc and the agglomerated microorganism.
Bio floc in aquaculture Bio floc is the main character to purify water and production of natural feed..
Bio floc system reduces problems with patogens.. This aggregate of bacteria and organic particles comprise an important part of the natural diet of shrimp and fish.
The floc contain an average of 45 % of protein, which is nearly double the protein level of the feeds
Nutritional Value of Algae• The principal advantage of
an algae-based production system is the nutritional value of phytoplankton – HUFAs– Carotenoids & other pigments
• Nutritional value depends upon species– Diatoms best source of HUFAs
• Managing species composition may be important
Cambia foto
Altre info sui valori nutrizionali
Bio floc intensive shrimp pond culture
In a very short time the pond is dryed and ready to be refilled and stocked
> LightFeedWaste
Aereation (air or pure oxigen)-Circulation-Turbolence
Bacteria-Cyanobacteria-Green algae-Diatoms-Dinoflagellates
Chemoautotrophs - photoautotrophs - heterotrophs
Biosecurity
Supplemental nutrition
Water quality
Waste managment - water reuse
- waste conversion
ComplexDinamicMicrobial community
45% proteins content
Mixing and aeration are key features of BFC technology> Supply oxygen to water
Aeration
Generate turbulence Degass CO2 from water
For biomass over 4 kg/m2 pure oxygen is required
> Keep Biofloc in suspension
> Provide vertical circulation
. Ammonia removal in aquaculture. > unlike nitrifying batteria that produce nitrite and nitrate, heterotrophic bacteria Incorporate ammonia nitrogen directly into microbial biomass.When using feed, only 1/3 of the dissolved organic carbon required by the hetrotrophic bacteria is available from the feed.This means that the additional organic carbon must be added for the heterotrophic bacteria to use all available ammonia generated by the shrimp
Mixing and aeration are key features of BFC technology
* Needed to reduce sludge deposition
* Suspend organic waste for digestion by bacteria * Prevent anaerobic zone
Circulation velocity from 10 to 20 cm per sec. Below 10 cm per sec. sedimentation can occur
Production: bibliograpy data tilapia 100 kg per cubic meter shrimp 300 to 700 stocking density with pure oxigen over 4 kg per square meter
Oxygen is a limiting factor in nitrification. To nitrify completely 1 gr of ammonia nitrogen 4,57 gr of oxigen are required.
Kg o2/kg feed =28 gr NH4-N x 4,47 gr O2 = 128 gr O2/kg feed for nitrification
Rule of thumb for total oxygen consumption:Oxygen requirement is sum of fish and bacterial oxygen consumption:
0,25 kg O2 consumed by fish 0,12 kg 02 by bacteria 0,37 kg 02---------------------------------------- + -------------------------------- = --------------- kg feed kg feed kg feed
It should be considered that the oxygen demand increase after feeding associated with digestion and assimilation of food. In the range 0f 1.1 kg of oxyigen per kg feed
Autotrophic system (photoautotrophic) green algaee low density production
Heterotrophic system………………………….. Brown algae medium density production Chemo autotrophic system………………… high density
Heterotrophic systemHeterotrophic bacterial growth is affected by the system’ s C/N ratio, temperature DO, PH, salinity.Increase in microbial biomass production is 40 times greater than the biomass generated from the nitrification process and consumption of O» is also much higher.> CO» production of hetereotrophic floc also is higher than autotrophic nitrifiers.
Danger parameters. CO2 danger zone, (illustrted:(CO2)> 20 mg/LNH3 danger zone as a f ( temperature, salinity, PH)(Illustrated : (NH3 )> 0.0125 mg/l & TAN 0,2 mg/L
Green zone defines a preferred PH- (Alk) regime (illustrated : PH 7,4 – 8,1 & (Alk)) 75 – 175 ppm CaCO3
….keep the system out the danger zone
Brown algae
Stocking density over 130 - 150 pl m2Aeration 28 32 hp ha
Belize 48 hpProduzione 13,500 kg ht550 kg x hp
Biofloc 643 kg hpSemi bio floc 540 kg hpTraditional 480 kg hp
Solids removal and control are very important tools to manage BFC systems
- Dominance of heterotrophs bacteria as grow faster than authotrophs bacteria, lead to variation in water quality High number of protozoans feed on heterotrophic bacteria Generates: high Bod, high CO2, low Ph
Foam FractionatorProtein Skimmer
Settling tank
Pre growing Raceway Round ponds
Products applicationsHatcheryPregrowing
Eco2: aeration, degassing, circulation, 3 interchangeable nozzles air or pure oxygen injector
Splash. Degassing, CO2 removal
Force 7: highest O2 transfer rateFlash. upside down vertical aeration and circulation
Culture: indoor and green houses
Products applicationsIndoorGreenhouses
Splash
Flash
Growing in small square concrete tanks Growing in small round concrete tanks
Growing in outdoor raceway
Growing..Medium size lined pond2000 m2
Growing..Medium size lined pond2000 m2
Product applicationForce 7Brio44
Brio 44
10.000 square meters pond
Products applicationForce 7Combo
Average stocking density 300/350 kg per hpPump operated nozzle aerator
Biofloc require oxygen and degassing
Force 7 offers: Best oxygen transfer rateDegassingPropeller design according to specific target to prevent anaerobic area
Biofloc must be kept in suspension. Sedimentation has to be avoided.Water circulation is a must.
Rio:Low power consumptionHighest volume of water
Combo:Best oxygen transfer rateIncomparable to any other system
Brio 44/ 47DegassingHuge splashed waterSteady circulation
FlashConcentrate oxygen dissolution
SplashCo2 strippingDegassingOxygen transfer rate
ProtosSkimSkim One
Foam fractionatorion to rigenerate old floc with new ones Degassing Reduce nitrate Balance PH
Water recycling