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

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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