SHELLFISH SPECIFICATIONS

SHELLFISH SPECIFICATIONS RESEARCH AND DEVELOPMENT OF AN ACCELERATED DETOXIFICATION SYSTEM FOR LIVE MARINE SHELLFISH CONTAMINATED BY ALGAL PSP TOXINE

CRAFT CONTRACT N° QLK1-CT-2002-72076 DELIVERABLE D04 SUMMARY 1

SCOPE .......................................................................................................................................................... 2

2

SYSTEM DESCRIPTION .......................................................................................................................... 2 2.1 2.2

3

CONSTRAINTS REMINDER.................................................................................................................... 4 3.1 3.2

4

GENERAL DESCRIPTION ......................................................................................................................... 2 SYSTEM FUNCTIONS .............................................................................................................................. 3

USERS REQUIREMENTS ........................................................................................................................ 4 BIOLOGICAL CONSTRAINTS ................................................................................................................... 4

EQUIPMENT............................................................................................................................................... 5 4.1 4.2 4.2.1 4.2.2 4.2.3 4.2.4 4.2.5 4.2.6 4.3 4.4 4.5

OVERVIEW ............................................................................................................................................ 5 SPECIFIC EQUIPMENT CONSTRAINTS ...................................................................................................... 5 Biological filter ........................................................................................................................... 5 Tanks........................................................................................................................................... 9 Phytoplankton injector................................................................................................................ 9 Fluorometer ................................................................................................................................ 9 Pumps and valves........................................................................................................................ 9 Thermoregulation ....................................................................................................................... 9 PROCESS CONTROL ................................................................................................................................ 9 VARIOUS CASES STUDY ....................................................................................................................... 10 SUPPORT AND ANCILLARIES ................................................................................................................ 10

5

ENVIRONMENTAL CONSTRAINTS ................................................................................................... 10

6

MAINTENABILITY REQUIREMENTS................................................................................................ 10

7

DOCUMENTATION................................................................................................................................. 10

ANNEX 1 : AMMONIA TOXICITY ON BIVALVES (BIBLIOGRAPHY) ................................................. 11 ANNEX 2 : PALLOX DESCRIPTION ............................................................................................................. 12 ANNEX 3 : PHYTOPLANKTON INJECTORS .............................................................................................. 14

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1 SCOPE The aim of the specifications report is to propose a general description of the pre-industrial pilot : defining the main orientations concerning the needs, the environment, the functionalities and the constraints of the system while respecting the state of the art regulations, in order to have the basic requirements and constraints to design the pre-industrial pilot. 2

SYSTEM DESCRIPTION

2.1 GENERAL DESCRIPTION The layout of a case with detoxification basin and closed circuit with water supply is presented in figure 1.

Figure 1- System overall block diagram

The capacity of the industrial system would be between 0.5 and 5 tons : the pre-industrial pilot will have a capacity of 150 kg that is a representative scale of the industrial aimed product. The detoxifying time will be 4 to 6 days (but if possible 3 days). One of the challenges will be to keep the operating costs at the lowest possible level, i.e. 0.03-3/kg (depending on the kind of shellfish).

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2.2 SYSTEM FUNCTIONS The system comprises functionally the following parts: 1. Water circulation and distribution : to ensure a correct flow in the whole circuit Circulation (valves, water lines) Pumping Fresh water 2. Shellfish storage : to arrange the shellfish in a comfortable manner so as they are able to filter correctly Tank Baskets 3. Shellfish feeding : to supply the fodder algae in a correct quantity Distribution Control 4. Quality control : to keep the quality of the water to the limits which are safe for shellfish and for the environment Measuring devices Correcting devices (filters) Effluent treatment (buffer tank, settling, chlorination, sewer) 5. Process control : to control the whole process in order to take appropriate action if a parameter goes wrong Control Supervision 6. Ancillaries : to supply everything necessary for the logistic support Energy supply.

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3

CONSTRAINTS REMINDER

3.1 USERS REQUIREMENTS The users requirements came from the results of the initial inquiries at the beginning of the project. Detoxification time : 3 to 6 days Average volume from 1 to 5 tonnes Space required for device : 10 to 20 m2 Agreed investment costs : K 5 to 450 Agreed functioning costs : 0.03 to 0.6 /kg Daily handling time : 20 to 60 minutes. 3.2

BIOLOGICAL CONSTRAINTS The dissolved oxygen level in the water is at almost 90% saturation Dissolved ammonia level inferior to 0.8 ppm; this rate is the result of a bibliographic inquiry (see annex 1) and could be confirmed by the experiments. The limited level of 0.8 ppm as limited concentration is decided so as to be situated : Largely below the ammoniac toxicity threshold for bivalves studied here and, in any case under the thresholds of «start of toxicity » with NOEC (No Observed Effect Concentration). In the range of known possible techniques in the non-stop treatment of nitrogen in closed circuit. Non toxic : usage of alimentary type plastic material excluding all metallic parts with the exclusion of stainless steel and titanium (all alloys based on Cu Ni, are notably specified). Fixed temperature of 16 to 20°C (Shellfish experimentations results). Water treatment device transparent to algae fodder flood : the principal costs of functioning as well as logistics make algae fodder a very sensitive post. So as to limit the needs as near as possible to those generated by the bivalves, the water treatment devices should not take samples by retention, notably mechanical on filters. Respect ratios issued from enquiries.

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4

EQUIPMENT

4.1 OVERVIEW Figure 2 is the layout of the principal of water treatment. Thermo regulation

Regulation

Distribution basins

Biological filter

Buffer tank

Pump

Sedimentation tank

Raw water

Figure 2

Mechanical filter

UV

Water treatment schematic diagram

The water treatment loop includes: A sediment chamber (lamellar type or not) integrated in the buffer tank Putting into circulation by pumping 2 m3/h with flow control A biological filter with clay filtering media expanded in large diameter A reversible thermoregulation unit with automatic regulation integrated An alimentation with raw water and mechanical filtering and UV treatment An algae s concentration control device connected to an injection feeder pump on a pressurised canalisation. A device or procedure for measuring nitrogen salts. 4.2 4.2.1

SPECIFIC EQUIPMENT CONSTRAINTS Biological filter DIMENSIONING ELEMENTS NH4 productivity values of oysters taken as reference (experiment results): Table 1 14°C

15.15 20.65 17.12 17.64

Temperature 16°C 18.21 18.00 5.40 13.87 No effect detected

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NH4 production (µg NH4/oyster/l/d) Algal concentration [c]=72 111 cells/ml [c]=32 892 cells/ml

20°C 17.33 16.60 14.01 15.98

33.86 18.54 26.20 Effect detected

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16.93 14.97 15.95 No effect

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20,00

20,00

15,00

15,00

10,00

10,00 5,00

5,00 0,00 04-avr

0,00 09-avr

14-avr

Figure 3

19-avr

24-avr

11-oct

29-avr

16-oct

21-oct

26-oct

31-oct 05-nov

NH4 production according to temperature (left) or feeding (right)

NH4 production evaluation Productivity: 0.26 µg/litre/individual/day Or : for 130 litres for 0.55 g average individual weight a production of: 61.45 mg NH4/Kg/day Security margin C =1.5 Production taken into account for the dimensioning : a production of 92.18 mg NH4/Kg/day Prototype size determination The constraints bound to the size of the module of the prototype treatment result in : The necessary mobility of the device in regard to variability of test sites, these depend on the natural contamination zones Available space at partners destined to receive the prototype (Sud coquillage in Bouzigues, France; Goro, Italy) A minimum size to permit overtaking the laboratory stage. Taking into account all of these constraints, the choice of size for the prototype is : Maximum capacity in instantaneous stock : 150 Kg of shellfish Storage volume : 1.5 m3 in three tanks Buffer tank volume : 0.5 m3 in one tank Circulating flow : 100% volume or 2 m3/h.

On the basis of experimental results first experiment IFREMER, to be confirmed on an experimental device. Shellfish 112-01a/03-04

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BIOLOGICAL FILTER GAUGING Figure 4 and tables 2&3 gives a dimensioning situation with a production of 61.45 mg NH4/Kg/day. Figure 5 and tables 4&5 gives a dimensioning situation with a production of 92.18 mg NH4/Kg/day, i.e. with the safety margin factor of 1.5. Option 61.45 mg/kg/day

Table 2 -

V

T°

0,14

25

0,12 20

Temperature (°C) Volume of the circuit Turnover Faeces

Filter volume (m3) 2 m3 2 m3 / h 61.45 mg/kg/d

0,10 15

0,08 0,06

10

0,04 5

Volume Filtre Filter volume Température Temperature

0,02

0 1

Figure 4

2

3

4

5

6

7

Table 3 -

Filter volume vs. Temperature (1st option)

Table 4 -

Option 92.18 mg/kg/jour

T°

V 0,25

25

0,20

20

0,15

15

0,10

10 Filter volume Temperature

0,05

5 0

1

Filter volume (m3) 0.13 0.12 0.12 0.11 0.10 0.10 0.09

Temperature (°C) 15 16 17 18 19 20 21

2

3

4

5

6

7

Temperature (°C) Volume of the circuit Turnover Faeces

Filter volume (m3) 2 m3 2 m3 / h 92.18 mg/kg/d

Table 5 Temperature (°C) 15 16 17 18 19 20 21

Filter volume (m3) 0.21 0.19 0.18 0.17 0.16 0.15 0.14

Figure 5 - Filter volume vs. Temperature (2nd option)

To conclude, whatever option is retained in terms of excretion (61.45 or 92.18 mg/kg/day) the results will advance in the same direction : the higher the water temperature, the more lower the filtering volume (which is logic in terms of bacteria metabolism). This dimensioning with a temperature lower than the circuit optimum will always have a margin depending on the routine. This margin could then allow for either a lowering of temperature in the circuit, or a peak in the production of nitrogenous products. It should be noted that the dimensioning simulations were achieved with a model developed for fish farming.

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At 20°C, the optimal filtering volume is situated between 0.10 and 0.15 m3. BIOLOGICAL FILTER DIMENSIONING BY SIMULATION Table 6 gives a simulation to know by another way the filter dimensioning. Table 6 - Basic dimensioning biological filter Flow to be treated in m3/h input m3/sec

calculation Diam

2 0.0006

Passage speed in m/h 18 0.0050

m/sec

Filtrage surface in m2

Volume in m3

0.11111 0.376

0.13333

Flow to be treated: Optimal passage speed : Minimum height of filter: Optimal passage time:

Minimum height 20

in m 1.2

Passage time (4 min) dry min

240 4

D = 2 m3/h V = 18 to 20 m/h H = 1.2 m T = 4 minutes

So the calculated results are the following: S (filtering surface) = D / V = 0. 1111 m2 with d (filter diameter) = 2 (S / ) = 0.376 m from where V(Filtering volume) = S * H = 0.14 m3 We can see that the results obtained in this way are in coherence with precedent calculations integrating the temperature. TYPE OF BIOLOGICAL FILTER It is necessary to reduce the build up of feeding algae on the filter surface, in order not to increase its consumption. At prototype level, the material used will be of a sand filtering type with collecting arms; packing adjusted (as to the volume of material for bacterial fixation) to the efficiency calculation of the biological filter. It will be constituted imperatively of plastic material with or without reinforcements (fibreglass ). The filtering media will be of an expanded clay type with a grain size not inferior to an average of 3 mm diameter of particles (this so as to optimise the transparency of the filter to the phytoplankton flow). At industrial level, the filters will be of deck and buselure type of a professional range, plastic body and control portholes.

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SHELLFISH SPECIFICATIONS

4.2.2 Tanks The tanks will be of the pallox kind with standard dimensions: Exterior dimension: L: 1 200 mm l: 1 000 mm h: 790 mm Interior dimension:

L: 1 110 mm l: 910 mm h: 610 mm

Details : unit equipment with false bottom and recuperation bung in the lower part of tank so as to test a configuration of tanks in columns (see annex 2). 4.2.3 Phytoplankton injector It will inject under pressure the phytoplankton concentrated culture. In this case it is a membrane system which compresses a liquid volume to be injected so as to dispose of a differential between the circulating fluid pressure recipient (here filtered sea water) and that which is to be injected (here concentrated algae culture). The injected volume should be at least equal to 10 liters /h (value to be verified depending on type of culture and its concentration). See annex 3 for some models. 4.2.4 Fluorometer It is used to measure the residual phytoplankton concentrations after passage in decontamination tanks (consumption by the bivalves) and in the water treatment devices (biological filter, lamellar sedimentation tank and thermoregulation [possible loss to be minimized]). 4.2.5 Pumps and valves Working range of : between 1 and 10 m3/h for 15 m HMT [Total Dynamic Head] Body and pieces non metallic (except stainless steel and titanium) Solenoid valve piloted on a vane flow-meter guaranteeing a constant flow of 2m3/h. 4.2.6 Thermoregulation The device should be capable of cooling or heating the circulating volume and to automatically maintain the temperature. Preferably the exchangers will be of titanium (a metal that resists corrosion and weak currents). The heating / cooling load will be better than 6 KW. 4.3 PROCESS CONTROL The process control will be based on a PC or a programmable controller fitted to the environmental conditions of a producer. The interface includes a Man Machine Interface (MMI) with display and a power interface connected to the actuators. MMI will allow for quick visualisation of the good working order of the system; or for the appearance of problems as well as to their localisation. It will be easy and user friendly for non-specialised workers. It has a sound and visual alarm when events occur which effect the good working of the detoxification process (as for NH4 rate reaching the threshold, stopping the algal distribution, a filter pressure above threshold, etc.). The parameters concerning the maintenance will be easy to access for a technician.

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4.4 VARIOUS CASES STUDY So as to have a good idea of the whole experimental device, the option retained here is a shelf basin. This type of option is not favourable to surface occupation constraints, in particular in regard to specifications arising from questionnaires. In this case, it is a good idea to test a shelf device (two or even three superimposed pallox type tanks) in the same conditions and with the same material as that used in the basic solution for the prototype. 4.5 SUPPORT AND ANCILLARIES The power supply will have the following characteristics : 230V 5%.

10%; single phase; 50 Hz

5 ENVIRONMENTAL CONSTRAINTS The system could be placed either in a sheltered place or outdoors. The following constraints are for outdoor working conditions. Table 7 Temperature 5 45°C

Sun

Environmental constraints

Moisture 100%

Rain

Wind 100 km/h

Ice / Snow no

6 MAINTENABILITY REQUIREMENTS The running of the system should be very simple so that the worker spends less than one hour a day, without major changes to the existing aquaculture system/approaches currently in place by the majority of producers. Moreover, the person entrusted with the maintenance should be able to check the system once a week together with the normal regular checks. Finally, the corrective maintenance should be rapidly efficient (i.e. less than one hour is desirable). 7 DOCUMENTATION Information will be prepared for the following documentation : General documentation. User s manual Technical manual Maintenance manual.

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ANNEX 1 : AMMONIA TOXICITY ON BIVALVES (BIBLIOGRAPHY)

A bibliographic inquiry has been conducted to compare the level of toxicity given for ammonia on bivalves in order to decide of the threshold.

Table 8

Author(s) Wang

Year 1989

Wang

1985

Abraham et al

1996

Epifanio and 1975 Srna Ringwood et 1998 Keppler Silvany et al 1999 Xu

1991

Ammonia toxicity on bivalves (bibliography)

Species Anadara granosa Ruditapes philippinarum Crassostrea gigas (larvaes + juveniles) Placopecten magellanicus Mercenaria mercenaria Crassostrea virginica All marine bivalves Mercenaria mercenaria Crassostrea virginica Mercenaria mercenaria (spat) Crassostrea rhizophorae (embrio) Potamocorbula laevis

Shape NH3 NH3 ? ? NH3

Toxicity LC 50 168H from 0.65 to 5.4 mg/L ??

NH3

LC 50 96H : 1.0 mg/L Start toxicity : 3.3 Start toxicity : 6.0 Limits : 3.0-6.0 mg/L LC 50 96 H : ? ? « Very resistant » NOEC : 14-16 mg/L

NH3

???

NH3

Increased toxicity with a thermal shock

NH3

Considering these figures and the experiments results, the threshold has been fixed at 0.08 ppm (roughly 20 atg.l-1).

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ANNEX 2 : PALLOX DESCRIPTION

Pallox fact sheet Capacity :

670 l

Exterior dimension :

L = 1.200 m l = 1.000 m h = 0.790 m

Interior dimension :

L = 1.110 m l = 0.910 m h = 0.610 m Figure 6 - Pallox

Inside the pallox

Figure 7

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Pallox details : overflow (left and middle) and false bottom (middle and right)

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600 l Pallox

Buffer tank

Lamellar settler

Figure 8

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Pallox in vertical configuration

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ANNEX 3 : PHYTOPLANKTON INJECTORS

Lt/h

Multiple phytoplankton injector

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