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Calix Australia

 

AQUA-Cal+

 

YIELD IMPROVEMENT IN SHRIMP & PRAWN GROW OUT
USING A NEW MINERAL-BASED TECHNOLOGY

 


 

Water Technologies Award Winner Business Innovation & Technology Leaders Australian Certified Organic

 


 

INTRODUCTION TO AQUA-Cal+

AQUA-CAL+ IS A 60% SOLIDS SLURRY MADE FROM “HONEYCOMB” MAGNESIUM OXIDE

 

Magnesium Oxide HoneycombThe results of trials over 2 years on the grow-out of prawns and shrimp show:

  • A reduction in sulphur odour;
  • A reduction of iron
  • A reduction of dissolved ammonia
  • A reduction of nitrite With an increase in yield for both Monodon and Vannamei. This paper proposes the Struvite mechanism that gives rise to these benefits.

 

This Presentation

  1. Monodon Field Trials
  2. Vannamei Field Trials
  3. Laboratory Tests
  4. Efficacy and the Role of Struvite
  5. Summary of AQUA-CAL+ Benefits

 


 

1. MONODON in EARTHEN PONDS PRE-TREATMENT – THE REMOVAL OF IRON

High Iron Before Treatment with AQUA-Cal+2 Days After Treatment with AQUA-Cal+

High Iron Before Treatment
2 Days After Treatment

 

 

 

AQUA-Cal+No iron presence after pre-treatment with

 

 

 


 

1. MONODON in EARTHEN PONDS THE REDUCTION OF NITRITE IN JAR TESTS

 AQUA-Cal+ Jar Test

 

AQUA-Cal+ jar test shows that the sediment / organic solids has been significantly dropped to the bottom and reduced the turbidity!

 Nitrite Tests show that AQUA-Cal+ treatment reduces nitrite

 

Nitrite Tests show that AQUA-Cal+ treatment reduces nitrite

 


 

1. MONODON in EARTHEN PONDS POST TRIAL – POND BOTTOM HEALTH

 

Pond with AQUA-Cal+ was clean and not smelly under the nose test.Pond with AQUA-Cal+ was clean and not smelly under the nose test.

Pond with was clean and not smelly under the nose test.


 

1. MONODON in EARTHEN PONDS HARVEST SUMMARY FROM MALAYSIAN TRIALS

HARVEST SUMMARY FROM MALAYSIAN TRIALS

 

Revenue is in Malaysian Ringgit:

 

Market Shrimp Price/kg
46pcs- RM28.50
33pcs- RM35.00
36pcs- RM33.50

 


 

2. VANNAMEI in LINED PONDS AMMONIA MEASUREMENTS

Ammonia Control

 

Ammonia Control

 

Control - daily drainage

AQUA-Cal 1 - weekly dosing and weekly drainage,
AQUA-Cal 2 - weekly dosing monthly drainage.

 


 

2. VANNAMEI in LINED PONDS NITRITE MEASUREMENTS

 

Nitrite Control

 

Week 3-13

 

Control - daily drainage

AQUA-Cal 1 - weekly dosing and weekly drainage,

AQUA-Cal 2 - weekly dosing monthly drainage.

 


 

VANNAMEI in LINED PONDS ALKALINITY MEASUREMENTS

 

Alkalinity Control

 

Alkalinity Control

 


 

2. VANNAMEI in LINED PONDS HARVEST SUMMARY FROM MALAYSIAN TRIALS

 

HARVEST SUMMARY FROM MALAYSIAN TRIALS

 

Revenue is in Malaysian Ringgit

 

 


 

3. LAB TESTS - TOXICITY and DOSE RATES for VANNEMEI

 

TOXICITY and DOSE RATES for VANNEMEI

 

The average LC50 of AQUA-Cal+ for 358-478 406 ppm within 50-56 hours.

The recommended dose for AQUA-Cal+ is 60-100ppm over the entire grow out including pretreatment.

At this dose, AQUA-Cal+ is safe to us.

 


 

3. LAB TESTS AQUA-Cal+ SLUDGE DIGESTION after 4 months

 

Significant sludge reduction using AQUA-Cal+ both with and with out aeration

 

Significant sludge reduction using AQUA-Cal+ both with and with out aeration. Test was conducted over 120 days.

 

Alkalinity and Vibrio Green Levels

  • Alkalinity – Increased by 73%
  • Green Vibrio - Disappeared

 

4. EFFICACY AND THE ROLE OF STRUVITE

The results of trials over 2 years on the grow-out of prawns and shrimp show:

  • A reduction in sulphur odour;
  • A reduction of iron
  • A reduction of dissolved ammonia
  • A reduction of nitrite

With an increase in yield for both Monodon and Vannamei.

 

Why?

 


 

4. THE STRUVITE DISPLACEMENT REACTION

 

Magnesium Oxide HoneycombThe “honeycomb Magnesium Oxide” has a porosity of about 50% and a surface area of 300-350 m2/g , and is then hydrated to form a 60% solids slurry.

 

When Magnesium Hydroxide is added to aquaculture ponds, struvite initially precipitates in the pores of the magnesium hydroxide particles by the homogenous displacement reaction.

 

magnesium hydroxide particles

 

This reaction occurs in the pores of the particle, and releases the hydroxide ion to neutralize the acids. Studies at the University of Queensland suggest this reaction occurs in the particle pores without the need for the magnesium to dissolve. Over time, the whole particle is transformed to Struvite.

 


 

4. THE STRUVITE DISPLACEMENT REACTION THE IMPACT ON SLUDGE DIGESTION

AQUA-Cal+ is a flocculant and forms a compact sludge The consumption of ammonia and phosphate from the aerobic sludge digestion process results in the formation of struvite, accompanied by the release of hydroxide ion, allowing the sludge to maintain the aerobic digestion process as long as the particles of magnesium hydroxide are available within the sludge. Hence, AQUA-Cal+ improves the degree of sludge digestion and reduces the formation of H2S and pathogens such as Vibrio this is achieved by suppression of anaerobic digestion and the ability of AQUA-Cal+ to inhibit pathogen growth.

 


 

4. THE CONSEQUENCES OF THE STRUVITE DISPLACEMENT REACTION

  1. Soluble phosphate in the water is reduced
  2. Soluble ammonia in the water is reduced
  3. Formation of nitrite and nitrate is reduced because the soluble ammonia is reduced
  4. The release of hydroxide raises the pH of the pond bottom close to neutral
  5. The sludge remains substantially aerobic, so that H2S formation is suppressed
  6. The iron is precipitated onto the particle surface where it is oxidized and incorporated in the struvite crystals as a substitutional impurity
  7. The struvite is incorporated into the sludge
  8. The struvite is a fertilizer that may be consumed by the algae for shrimp and prawn food

 

5. SUMMARY SUMARY OF AQUA-Cal ADVANTAGES OVER CURRENT PRACTICES

FOR THE SHRIMP/PRAWNS

  1. Safe for shrimp/prawns & environment
  2. Reduces formation of toxic H2S (and odour)
  3. Removes toxic Ammonia & Nitrite
  4. Removes toxic iron
  5. Stabilizes the pH & Alkalinity
  6. Controls Green Vibrio
  7. Improves pond bottom health

FOR THE FARMER

  1. Utilizes a current waste and potential toxic product the bottom sludge.
  2. Increase harvest weight
  3. Increases survival rate
  4. Reduces FCR
  5. Potential for increased revenue to the farmer

 

5. ACKNOWLEDGEMENTS

  • Dr Mark Sceats – Calix Australia
  • Blue Archipelago – Malaysia
  • Manjung Aquatic – Malaysia
  • Maha Chemicals - Malaysia
  • University of Queensland – Australia

 

Creating new materials, solving global challenges.

 

Calix Australia - Creating new materials, solving global challenges.

 

Contact Calix

 

(02) 8199 7400

 

info@calix.com.au

9 Bridge St, Pymble NSW 2073