Wisconsin Aquaculture Conference
March 7-8, 2014
Algae Integrated Aquaculture
Jun Yoshitani
AlgaXperts LLC
[email protected]
www.algaxperts.com
630-890-8776
Presentation Topics
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About AlgaXperts
What are algae?
Aquaculture wastewater
Examining integration of algae into RAS.
Turning liability into asset
Take aways
About AlgaXperts (1/2)
• Applied phycology and algal wastewater engineering.
• Founded in 2009 by L.E. Graham, J.A. Graham and J. Yoshitani.
• A collaboration of scientists and engineers who share in the
vision that algae offer enormous benefits for society.
• Three areas of focus:
 Algal treatment of wastewater
 Integration of algae into aquaculture
 Algal derived products
About AlgaXperts (2/2)
• Located in Global Water Center, Milwaukee, WI.
• Past and current projects include R&D on algae biofuel,
feasibility study of algal wastewater treatment, pilot study of
algal nutrient removal, and algal food production.
• Majority of collaborators have advanced degrees and bring
many years of experience in their respective fields.
Jun Yoshitani, MS, MBA, Env. Engineering
Charles Bensinger, B.A., Renewable Energy
Linda Graham, PhD, Phycologist (UW-Madison)
Steven Lyon, Ph.D., Environ. Microbiology
James Graham, PhD, Phycologist (UW-Madison)
Mike Piotrowski, MS candidate UW-Madison
Erica Young, PhD, Phycologist (UW-Milwaukee)
Nicholas Dettman, BS candidate UW-Madison
John Berges, PhD. Pycologist (UW-Milwaukee)
Jennifer Knack, MS candidate UW-Madison
Lee Wilcox, Ph.D. Phycologist
Li Xiao, Ph.D., Environmental Engineering
What are algae?
• Algae are a diverse assemblage of organisms that are mostly
photosynthetic, produce oxygen and live in aquatic habitats.
• Algae lack the body and reproductive structures typical of land
plants.
• Algae include photosynthetic protists (eukaryotes with a true
nucleus in the cell) and cyanobacteria or blue-green algae,
which are prokaryotes and lack a distinct nucleus in their cells.
A cyanobacterium
Protists
Some exceptions include:
• Some photosynthetic protists have closely related nonphotosynthetic relatives that ingest organic food
Euglena
Entosiphon
• Euglena has many heterotrophic relatives that together
form a lineage called the euglenoids.
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Some algae occur in non-aquatic habitats such
as soils, rocks, and surfaces of plants.
Biological soil crusts formed
on western rangelands, leftUSGS, above NPS.
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Terrestrial algae become dormant when moisture is
absent.
Pond Scum
Giant Kelp
Cladophora
Diatom
Arthrospira
Chlorella
Haematococcus
Cladophora in Milwaukee
creek
Aquaculture wastewater
Fish feed containing
macro and micronutrients
Dissolved O2
in water
Digestion breaks down organic compounds
Carbon dioxide
Unconsumed fish feed
Feces
Aquaculture wastewater
(Ref: Aquacutlure Effluents and Waste By-Products by S. Yeo and F. Binkowski)
Aquaculture wastewater include
• Biological oxygen demand (BOD).
• Total solids (suspended and dissolved).
• Total ammonia (NH3 and NH4) un-ionized NH3 is highly toxic
to fish.
• Total phosphorus
• Effect of waste on fish rearing water:
 Decreases dissolved oxygen
 Increases carbon dioxide
 Reduces alkalinity
 Changes pH
With exception of total suspended solids, algae can partially
or wholly reverse negative effects of aquaculture
wastewater.
Light
106CO2+6HNO3+H3PO43- +78H2O
Algal biomass
Source: Brune DE, Algal Production for
Sustainable Aquaculture , Presented at
ABO Summit 2010, Phoenix, AZ
C106H175O42N16P+150O2
Examining algae integration into RAS
Typical RAS block flow diagram
Fish rearing
tank
Oxygenation
Pathogen
control
Solids/liquid
separation
Nitrification/
denitrification
CO2
degassing
Solids
dewatering
Filtrate
Sludge
disposal
Algal integrated RAS block flow diagram
Fish rearing
tank
Pathogen
control
Light
Solids/liquid
separation
Macroalgae
harvesting
Macroalgae
cultivation
Microalgae
harvesting
Solids
dewatering
Pathogen
control
Sludge
disposal
Light
Microalgae
cultivation
Comparison of conventional vs algae
integrated aquaculture for RAS
Parameters
Conventional
aquaculture
Algae integrated
aquaculture
Ammonia
Requires biological
nitrif/denitrification
Incorporated into algal
biomass
Phosphate
Requires ultra membrane Incorporated into algal
filters
biomass
Carbon dioxide
Requires degassing
equipment
Incorporated into algal
biomass
Requires oxygenation
Dissolved oxygen
equipment
Oxygen supplied by algal
photosynthesis
Pathogens
UV, ozone, induction
UV, ozone, induction
Open raceway algae cultivation
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Requires land
Low capital and operating cost
Low biomass productivity
Process control is difficult
May require importing C, N,
Evaporation can be a serious
problem for both indoor and
outdoor systems.
Primarily used for microalgae
Microalgae are difficult to
harvest
Closed photobioreactor algal cultivation
• High capital cost
• Operating cost may also be
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high.
May be located inside
enclosure or outside
Typical problems include high
temperature, pH, solids
settling, oxygen toxicity,
biofilm build-up on inside
surfaces.
May be used as inoculum
reactor.
Only for microalgae
Hanging bag
Tubular
Turning liability into asset
• Growing algae that have value as substitute for fish meal.
 Microalgae
 Macroalgae
• Growing algae that have value as nutritional suplement for
human consumption.
Growing microalgae as substitute for fish meal
Fishmeal and fishoil
to be exhausted by
2040.
Marine food production (mariculture
products, wild fisheries, and
harvest of natural macroalgal
stocks (Duarte, 2009). Projection
derived from assumption that wild
fisheries and harvest of natural
macro-algal stocks will be
maintained at 2005 levels, and
mariculture to maintain it’s current
7.5% per year growth.
Depleting supply of fish meal is causing price
to rise - $700 to $1800/tonne in 10 years.
Many common algae provide protein, lipid and
carbohydrates similar to fish meal
Alga Species
Spirulina platensis
Spirulina maxima
Chlorella vulgaris
Chlorella pyrenoidosa
Scenedesmus obliquus
Scenedesmus quadricauda
Dunaliella salina
Synechococcus
Euglena gracilis
Hormidium
Protein (%)
46 – 50
60 – 71
51 – 58
57
50 – 56
47
57
63
39 – 61
41
Lipids (%)
4–9
6–7
14 – 22
2
12 – 14
2
6
11
14 – 20
38
Carbohydrates (%)
8 – 14
13 – 16
12 – 17
26
10 – 17
32
15
14 – 18
Amino acid concentration (g/100g) of microalgae
Amino Acid
Isoleucine
Leucine
Valine
Lysine
Phenylalanine
Tyrrosine
Methionine
Cystine
Tryptophan
Threonine
Alanine
Arginine
Aspartic acid
Glutamic acid
Glycine
Histidine
Proline
Serine
Egg
6.6
8.8
7.2
7.0
5.8
4.2
3.2
2.3
1.7
5.0
6.2
11.0
12.6
4.2
2.4
4.2
6.9
Ave. of 6 microalgae
4.8
9.6
6.9
5.8
5.2
3.8
1.8
0.8
0.7
5.4
9.4
6.9
10.2
12.6
6.9
2.0
4.3
4.9
Spirulina may be a candidate for integration into
aquaculture with fish meal nutritional value
Magnified
After one week
After three weeks
Spirulina are
relatively easy to
grow, harvest and
process. Large
body of knowledge
exists about
Spirulina
Tablet
Powder
Spirulina as fish meal substitute
• Commercial Spirulina powder: 46-70% protein, 8-16%
carbohydrate, 4-9% lipids, 7% ash.
• Essential fatty acids:
 γ-linolenic, γ-linoleic, stearidonic, EPA, DHA, AAA
 Vitamins B1, B2, B3, B6, B9, B12, C, D and E
• Minerals: K, Ca, Cr, Cu, Fe, Mg, Mn, P, Se, Na, and Zn
• Contains many pigments including chlorophyl a, xanthophyll,
beta-carotene, c-phycocyanin, etc.
• Allowable fish meal replacement varied from 15% to 50%.
Source: UN FAO Circular No. 1034
Algal integrated indoor RAS block diagram
Fish rearing
tank
Pathogen
control
Light
Solids/liquid
separation
Macroalgae
harvesting
Macroalgae
cultivation
Microalgae
harvesting
Solids
dewatering
Pathogen
control
Sludge
disposal
Light
Microalgae
cultivation
Macroalgae (filamentous green algae)
Rocky lake bottoms
Stormwater channels
Sewage plant surfaces
Cladophora glomerata
Macroalgae (filamentous green algae)
• Thousands of species of filamentous green algae.
• Grows attached to hard surfaces, e.g., concrete channels,
rocky lake bottoms, etc.
• Not subject to herbivory or grazing.
• Can grow in cold water as well as warm.
• ATS@ (Algal Turf Scrubber) often used as tertiary treatment
system for removal of total nitrogen and total phosphorus.
• As an attached growth filamentous algae forms dense biofilter.
• Requires regular removal to be effective.
• Removed or detached filamentous algae can be harvested
easily.
Uses for filamentous green algae
• Fish food for herbivorous species like Tilapia
• Biomass for thermochemical conversion into liquid fuel
• Uses for cellulose (about 20 to 45% dry wt of filamentous green
algae) include:
 Ultra fine filter – may be used as ion exchange membrane
 Rheology enhancer – foods, pharmaceuticals, paints
 Paper- high strength paper and paper based energy storage
devices (batteries)
 Cellulosic fibrils as reinforcements in polyurethane and other
foam materials.
 Drug excipients
Growing algae that have value as nutritional
supplement for human consumption
$20/gram
$45/gram
$83/gram
Use same growing technique as in algae integrated into
aquaculture, except medium would be non-wastewater
Take aways
• The science supporting algae integrated aquaculture is
established and understood.
• Most, if not all, technologies (i.e., equipment required for a
full scale system) exists.
• Algae integrated aquaculture is adaptable for small family
farms and scalable to larger operations.
• Algae turns liability (aquaculture wastewater ) into an asset.
• Algae integrated aquaculture can help the farmer increase
his/her profitability.
Thank you, and if algae interests
you, please call or email
Jun Yoshitani, P.E.
AlgaXperts LLC
www.algaxperts.com
Email: [email protected]
630-890-8776