application of levapor carriers for nitrification-denitrification in recycled aquaculture systems

Selection and performanceof biocarriers for aquacultures

with water reuse

Christoph GreckiWR IKRA DABIE

Poland

The fish hatchery and farm WR Dabie, Poland

Targets of the investigations

to improve the efficiency of the water recycle plant via increased nutrient removal, meaning • to find a more efficient biocarrier for the removal of fish toxic compounds,than existing plastic carriers

• to define the biokinetic parameter of the N-removal

• to develop an optimized technology for the N-removal.

NH3/NH4 NO2 NO3

Nitrosomonas Nitrobacter

fish toxic at >1,0 mg/L

tish toxic at> 0,5 mg/L

non toxicat 50 mg/L

Pathways and fish toxicities of inorganic nitrogen compounds

N2

denitrification

Test plant and mode of operation

Test plant : Biofilter with V = L volume, each filled with biocarrier

Biocarrier : PE carrier 780 m²/m³ , LEVAPOR >20.000 m²/m³ PU foam 1500 m²/m³ , Keramzit 400 m²/m³

Mode of operation : a filtered and aerated streams of the recycle water were forwarded through the non colonized carrier layers at xy sec retention time.

Sampling and analyses : grab samples were analysed twice in a week, NH4, NO2 and NO3 were determined.

The biofilter pilot plants

PE-carrier LEVAPOR PU foam Ceramics780 m²/m³ > 20.000 m²/m³ 1.500 m²/m³ 400 m²/m³

inlet

Removal of ammoniacal nitrogen by PE vs. LEVAPOR carrier over a week

CONCLUSIONS• In all tests LEVAPOR carrier have achieved highest degree of removal both for ammoniacal as well as for nitrite nitrogen

• The LEVAPOR supported nitrification achieved a ca. 100 % higher efficiency than the PE carrier supported biofilter

• Due to high porosity and carrier surface, the LEVAPOR supported reactor has achieved a remarkable NO2-removal

• The LEVAPOR supported biofilter removed 300% more (NH4+NO2)N than the PE carrier supported filter

• On basis of the achieved results the company has decided to apply LEVAPOR biocarrier in the new biofilters.

LEVAPOR biocarrier have been designed in labs.

Dimensions: 20x20x7 mm – Surface : 1,34 mio. m²/m³Bulk weight: 30 kg/m³ - Water binding capacity ~100 kg/m³Wetting: within few hours – Biofilm generation: 120 min.

Specialty: high content of powdered activated carbon enables unique effects, not only simple cell adhesion .

Effects: Adsorption of inhibitors lower toxicity in bioreactor faster bioprocess start stable

process

Scheme of a biofilter using biocarriers

The new biofilter to be filled with LEVAPOR