Innovative Waste-to-Algae

Technologies for Sustainable Algal

Biofuel and Byproducts Production

Wenguang Zhou Ph.D

And M Min, P Peng, Z Wang, X Ma, Z Fu, B Hu, Z Du, H Fida,

D Mu, J Hill, P Chen, R Ruan

Department of Bioproducts and Biosystems Engineering

University of Minnesota

The 7th Annual Algae Biomass Summit, Orlando, FL, USA Oct 2, 2013

• Free water

• Free nutrients

• Free flue gas

• Wastewater treatment

Remove N, P, COD

Reduce greenhouse gas

emission

Advantages of Waste-to- Algae System

Wastewater Resource

• Municipal wastewater

• Animal manure wastewater

Municipal and agricultural waste are widely available and

more uniform in characteristic than the variable

constituents of other types of wastewaters (e.g. industrial

wastewaters)

SMB

REL

N

Grit screen Primary settling tanks

Activated sludge process

Final settling tanks Disinfection

Sludge processing

Recycle stream

bacteria return

Sludge disposal

Centrate

Parameter Concentration (mg/L) Parameter Concentration (mg/L)

Soluble COD 2324 ± 40.1 PO43--P 212± 7.2

TOC 960±30.50 NH3-N 91±1.8

pH 6.31 ± 0.11 TKN 134± 6.8

NO3-N 0.35 ± 0.36 NO2-N <0.03

Total suspended solid 0.14±0.11

Characteristics of the Centrate Wastewater

Nutrient Profile of the fresh and Anaerobic

Digested (AD) hog Manure Wastewater

Nutrients concentration (mg/L) Solid content (g/L)

COD TN NH3 NO3-N NO2-N TP TSS TVSS

Swine manure

before AD

9300 3150 2960 -- -- 24.05 35.43 22.00

Swine manure

after AD

6480 3440 3200 -- -- 20.75 14.03 9.85

Fresh

Manure

Treatment

B1

Treatment B2

0 h 24 h 48 h 72 h

Acetic acid 2899.12 4535.2 3553.84 3797.15 6487.45 5744.43

Propionic acid 3540.26 3517.8 3923.73 4181.7 7066.33 5678.02

Butyric acid 333.52 533.2 264.96 293.41 258.13 325.87

Total 6772.9 8586.2 7742.53 8272.26 13811.91 11748.32

VFA Concentration in Swine Manure Wastewater

Isolation of native microalgal strains in Minnesota

Enrich in BG-11 Microscope observation

Filamentous algal strains with high lipid content

Cladophora sp and

Hydrodictyon sp

Greenish mats on

the water surface,

stringy, slimy,

lime-green clumps

or mats, fast-

growing high oil

algae.

Spirulina sp

Spirogyra sp

Ref: Fao Fisheries and Aquaculture Technical Paper 531

Local strain

ID

Collection

date Collection site Local strain ID Collection date Collection site

UMN220 Oct, 2006 a Twin Cities lake UMN253 Jun, 2006 Theodore Wirth Lake 2 on the beach

UMN221 Apr, 2006 RoseLawn Pond UMN254 Jun, 2006 Lake Calhoun

UMN223 Apr, 2006 Como Park Golf Course Pond #2 UMN255 Jun, 2006 Moore Lake

UMN224 Apr,2006 Como Lake UMN258 Jun, 2006 Rice Creek after the bridge inside the park

UMN225 Apr, 2006 McCarrons Lake UMN259 Jun, 2006 MayFlower drainage pond

UMN226 Apr, 2006 Rosville Park, Lexington south of County Rd C UMN260 Jun, 2006 Drainage pond behind Bachmans

UMN227 Apr, 2006 Oxford and County Rd C UMN261 Jun, 2006 Pond of Assisting Living banfill acrss apartments

UMN228 Apr, 2006 County Rd C and Victoria: north Pond UMN263 Jun, 2006 Marlenes's drainage at the park

UMN229 Apr, 2006 County Rd C and Victoria: north Pond UMN264 Jun, 2006 Metro Wastewater Treatment Plant dreft side

UMN230 Apr, 2006 Falls to the lake on County Rd C and Victoria UMN265 Jun, 2006 Kaller Lake

UMN231 Apr, 2006 Lake Johanna, west side UMN266 Jun, 2006 3M Innovation Plant lake

UMN232 May, 2006 swamp in west side of Lake Johanna across the road UMN267 Jun, 2006 Pond on Keller Lake

UMN233 May, 2006 next swamp across Lake Johanna UMN268 Jun, 2006 Maplewood: Lakewood and Maryland

UMN238 May, 2006 Lake Josephine east side UMN269 Jun, 2006 Mcarron's lake

UMN240 May, 2006 Drainage to Lake Josephine #2 UMN270 Jun, 2006 Margolis pond on Lapenteur

UMN241 May, 2006 Pond #1 across Rosville High School UMN271 Jul, 2006 Loon Lake, Waseca

UMN242 May, 2006 Pond #1 across Rosville High School UMN272 Jul, 2006 Loon Lake, Waseca

UMN243 Jun, 2006 Como Park lake UMN273 Jul, 2006 White Bear Lake

UMN244 Jun, 2006 Channel on Ripley road, Litchfield (at the golf course) UMN274 Jul, 2006 Bold Lake, east site

UMN245 Jun, 2006 Lake Ripley picnic area, Lithfield UMN275 Jul, 2006 Amelia Lake

UMN246 Jun, 2006 Pond between County Rd 1 and County Rd 23, Litchfield UMN276 Jul, 2006 Coon Rapids Dam #1

UMN247 Jun, 2006 Lake Hope, Litchfield UMN277 Jul, 2007 Pond at Marine City

UMN250 Jun, 2006

Theodore Wirth Parkway, Pond #3 on the right coming from

394 UMN278 Jul, 2007 Pond at Marine City

UMN251 Jun, 2006

Theodore Wirth Parkway, left, right Pond #2b around the

bridge UMN279 Jul, 2007 Spring brook 1, Fridley

UMN252 Jun, 2006 Theodore Wirth Lake 1, farther than the beach UMN281 May, 2006 Itasca main lake

Local microalgal strains established in the study

List of UTEX strains for the selection

UTEX ID Species UTEX ID Species UTEX ID Species

16 Haematococcus lacustris 302 Cosmarium botrytis 1779 Chlorococcum paludosum

20 Chlorella ellipsoidea 305 Cosmarium subtumidum 1782 Chlorococcum oviforme

25 Chlorella protothecoides 325 Selenastrum gracile 1786 Chlorococcum salsugineum

26 Chlorella vulgaris 326 Selenastrum minutum 1787 Chlorococcum sphacosum

32 Chlorella zofingiensis 343 Chlorella fusca var.fusca 1788 Chlorococcum texanum

46 Protosiphon botryoides f.pariet 398 Chlorella kessleri 1789 Chlorococcum typicum

55 Haematococcus droebakensis 414 Scenedesmus dispar 1904 Chlamydomonas zebra

63 Crucigenia tetrapedia 415 Selenastrum Acuminatus 2096 Characium bulgariense

78 Scenedesmus obliquus 416 Scenedesmus acutiformis 2097 Characium californicum

79 Scenedesmus basiliensis 417 Scenedesmus dimorphus 2108 Characium typicum

101 Ankistrodesmus falcatus var. 572 Botryococcus braunii 2168 Chlorella sp.

117 Chlorococcum minutum 580 Chlorella sp. 2219 Chlorella minutissima

120 Tetraedron bitridens 674 Navicula pelliculosa 2222 Chlorococcum aquaticum

127 Dictyochloris pulchra 748 Ankistrodesmus falcatus var. 2240 Chlorella minutissima

151 Monodus subterraneus 750 Ankistrodesmus braunii 2248 Chlorella sp.

187 Ankistrodesmus braunii 773 Tetracystis aplanosporum 2252 Dictyochloris schumacherensis

189 Ankistrodesmus angustus 972 Chlorococcum ellipsoideum 2341 Chlorella minutissima

190 Ankistrodesmus densus 1054 Chlamydomonas moewusii var. 2438 Chlorococcum sp.

208 Chlamydomonas sphaeroides 1230 Chlorella sorokiniana 2442 Coelastrum astroideum

228 Chlamydomonas dorsoventralis 1233 Chlorococcum scabellum 2445 Tetrastrum heteracantum

230 Chlamydomonas applanata 1236 Scenedesmus longus 2459 Scenedesmus minutum

241 Ankistrodesmus angustus 1237 Scenedesmus dimorphus 2498 Chlorococcum pamirum

242 Ankistrodesmus falcatus var. 1338 Chlamydomonas noctigama 2502 Nannochloris eucaryotum

244 Ankistrodesmus braunii 1344 Chlamydomonas debaryana var 2505 Haematococcus pluvialis

245 Ankistrodesmus braunii 1450 Scenedesmus obliquus 2527 Dictyochloris pulchra

246 Chlorella sorokiniana 1591 Scenedesmus sp. 2532 Scenedesmus subspicatus

251 Chlorella fusca var.vacuolata 1648 Selenastrum capricornutum 2551 Scenedesmus armatus

252 Chlorella fusca var.vacuolata 1767 Chlorococcum arenosum 2629 Botryococcus sudeticus

256 Chlorella protothecoides 1768 Chlorococcum aureum 2630 Scenedesmus obliquus

261 Chlorella sorokiniana 1769 Chlorococcum citriforme 2714 Chlorella vulgaris

280 Coelastrum microporum 1774 Chlorococcum macrostigmatum 2805 Chlorella sorokiniana

287 Oocystis marssonii 1776 Chlorococcum loculatum 2911 Chlorella saccharophila

299 Cosmarium impressulum 1777 Chlorococcum microstigmatum

Maximal Growth rate(d-1)

0 0.2 0.4 0.6

UM 235

UM 269

UM 268

UM 259

UM 231

UM 277

UM 270

UM 258

UM 273

UM 221

UM 271

UM 224

UM 281

UM 253

UM 284

UM 280

UM 265

Biomass productivity(mg L-1d-1)

0 100 200 300

Lipid productivity(mg L-1d-1)

0 20 40 60 80 100

Growth rate, biomass productivity, and lipid productivity of UM microalgal

strains grown on centrate wastewater.

Top-performing native microalgal strains grown

well on centrate Code Species Size(um) Maximal Growth rate(d-

1)

Biomass productivity(mg

L-1d-1)

Lipid productivity(mg

L-1d-1)

UM 221 heynigia. sp 6-9 0.431 210.4 50.8

UM 224 Chlorella. sp 6-10 0.455 231.4 77.5

UM 280 Auxenochlorella

protothecoides

6-9 0.492 268.8 77.7

UM 231 Chlorella. sp 7-9 0.391 179.2 41.7

UM 235 Chlorella. vulgaris 2-4 0.293 120.8 21.0

UM 281 Micractinium. sp 5-7 0.455 231.4 42.6

UM 258 Scenedesmus. sp 13-15 0.411 193.8 49.8

UM 259 Chlorella. vulgaris 3-5 0.367 162.5 36.9

UM 265 Hindakia sp 6-9 0.498 275.0 77.8

UM 268 Chlorella. sp 5-7 0.325 137.5 36.9

UM 269 Chlorella. sp 5-7 0.317 137.5 65.4

UM 270 Chlorella. sorokiniana 6-9 0.402 187.5 49.4

UM 253 Chlorella. sp 6-8 0.466 241.7 74.7

UM 271 Chlorella. sp 5-7 0.434 212.5 58.5

UM 273 Chlorella. sp 7-9 0.416 197.9 41.3

UM 277 Chlorella. sorokiniana 5-7 0.397 183.3 94.8

UM 284 Scenedesmus. sp 13-15 0.472 247.5 74.5

Top-performing microalgal strains grown well on

swine manure wastewater

RTVSS a represents the growth rate of microalgae.

Top-performing microalgal strains grown well on

swine manure wastewater

Screening for high CO2 tolerance Microalgae

Screening for high CO2 tolerance Microalgae

Screening for high CO2 tolerance Microalgae

Fatty acid Fatty acid content (%) in screened microalgal strain

UM221 UM224 UM280 UM231 UM235 UM281 UM258 UM259 UM265 UM268 UM269 UM270 UM253 UM271 UM273 UM277 UM2

84

C12:0 0.23 0.21 - - - - - 0.59 0.31 - - 0.19 - 0.1 - -

C14:0 - 1.87 - 0.89 2.93 1.41 4.12 1.24 1.12 5.13 - 0.77 1.03 1.48 4.09 0.44

C16:0 26.29 24.28 27.85 22.15 30.68 25.18 26.92 26.45 27.37 35.66 22.97 27.57 28.59 27.31 30.59 34.64 31.59

C16:1 0.95 - 0.18 0.2 6.36 0.66 5.77 4.62 0.12 17.72 0.27 6.89 6.43 3.12 0.72

C16:2 8.66 6.25 0.59 2.86 4.61 5.48 2.75 6.82 10.58 3.78 5.33 8.70 8.79 9.61 6.23 5.25 3.19

C16:3 - - 0.59 - - - - - - - - 8.67 8.57 - - - 6.44

C18:0 0.86 1.95 4.62 3.74 2.81 3.27 0.87 1.70 1.42 2.24 0.51 1.28 1.44 2.80 3.79 1.81 2.29

C18:1 11.88 4.74 - 10.40 0.23 9.14 31.73 37.42 5.86 - - 4.54 4.24 5.24 8.18 8.46 1.22

C18:2 31.08 30.28 28.75 22.81 19.38 34.98 15.86 23.88 32.15 23.91 18.37 28.67 29.28 31.57 19.09 25.98 10.12

C18:3 18.90 29.31 36.89 30.16 28.92 17.78 0.56 0.11 14.51 26.30 31.85 18.18 17.26 13.03 22.06 15.65 38.19

C20:0 - - - - - - 0.14 - 0.43 - 0.15 0.34 0.40 0.44 0.14 0.24 0.15

C20:1 - 0.2 - 0.23 - 0.16 0.13 - - - - - - - - - 0.45

C20:5 - - - 5.05 - - 7.58 - - - - - - - - - 0.13

C22:0 - - - - 0.17 0.11 - - 0.38 0.33 0.11 0.14 0.18 0.39 0.19 - -

C24:0 0.19 0.28 0.12 0.28 - 0.19 0.47 0.51 0.20 0.38 0.54 0.36 0.34

satua 27.91 28.78 32.96 13.00 37.88 31.38 35.62 30.00 32.01 44.56 24.78 30.81 31.46 33.07 37.72 41.47 40.47

monob 13.45 5.38 0.18 10.66 9.20 10.31 37.62 39.19 10.70 1.35 19.67 4.91 4.57 12.61 14.89 11.58 2.39

polyc 58.64 65.84 66.86 76.34 52.92 58.31 26.76 30.81 57.28 54.09 55.55 64.28 63.97 54.31 47.39 46.94 57.14

C16-C18 91.61 94.45 94.177 85.35 81.94 93.46 80.23 90.54 94.9 81.76 92.15 94.71 94.14 93.64 90.01 86.85 93.76

Total lipid 24.16 33.53 28.90 23.28 17.41 18.41 25.70 22.68 28.30 26.85 31.73 26.34 30.91 27.51 20.89 26.99 30.09

Screening Omega-3 PUFA Microalgal Strains

Grown well on Swine Manure for Animal Feed

FF

A (

%)

UM

231

UM

258

UM

268

UM

271

UT

EX

LB

1002

UT

EX

151

UT

EX

L1649

UT

EX

2341

C12:0 N/D N/D 0.31 N/D N/D N/D N/D N/D

C14:0 0.89 4.12 5.13 1.03 5.4 0.1 4.4 0.7

C16:0 22.15 26.92 35.66 27.31 30.9 18.7 20.6 11.9

C16:1 0.2 5.77 0.12 6.89 7.1 10.1 22.6 15.0

C16:2 2.86 2.75 3.78 9.61 N/D N/D N/D N/D

C16:3 N/D N/D N/D N/D N/D N/D N/D N/D

C18:0 3.74 0.87 2.24 2.80 10.5 0.9 9.0 7.8

C18:1 10.40 31.73 N/D 5.24 0.3 5.4 0.3 12.0

C18:2 22.81 15.86 23.91 31.57 5.6 2.4 2.3 6.3

C18:3 30.16 0.56 26.30 13.03 3.1 0.4 1.1 4.6

C20:0 N/D 0.14 N/D 0.44 N/D N/D N/D N/D

C20:1 0.23 0.13 N/D N/D N/D N/D N/D N/D

C20:5 (EPA) 5.05 7.58 3.96 N/D 15.1 34.2 N/D 31.3

C22:0 N/D N/D 0.33 0.39 N/D N/D N/D N/D

C22:6 (DHA) N/D N/D N/D N/D 17.0 N/D 19.9 N/D

FFA in biomass (% w/w)

7.08 9.77 8.77 9.43 6.85 9.93 11.1 6.53

FFA in oil (% w/w) 30.41 38.02 32.66 29.78 N/A N/A N/A N/A

Oil in biomass

(% w/w) 23.28 25.70 26.85 1.12 N/A N/A N/A N/A

Protein in biomass (%

w/w) 45.7 N/A N/A 52.04 N/A N/A N/A N/A

Ash in biomass

(% w/w) N/A N/A N/A 12.63 N/A N/A N/A N/A

Carbohydrates in

biomass (% w/w) 14.7 N/A N/A 32.21 N/A N/A N/A N/A

Screening Omega-3 PUFA Microalgal Strains

Grown well on Swine Manure for Fish Meal

Lab-scale Evaluation

0.0

0.3

0.6

0.9

1.2

1.5

0 5 10 15Bio

mas

s co

nce

ntr

ati

on

(g/L

)

Time (day)

100mL in flask

25L in coil

0

0.5

1

1.5

0 5 10

Bio

mas

s co

nce

ntr

atio

n

(g/L

)

Time (day)

Similar growth pattern during the first 3 days

Steady state starting from day 3 for small scale

Peaked on day 5 for scale up experiment, then dropped gradually (light limitation)

Continuous operation: 35% harvesting rate, biomass net growth 1.65 g/L per day.

Scale up and continuous operation stability

0

50

100

150

200

250

300

350

400

450

500

11/16/2009 11/26/2009 12/6/2009 12/16/2009 12/26/2009 1/5/2010 1/15/2010 1/25/2010

Date

So

lub

le T

ota

l P

ho

sp

ho

rus

- m

g/l

Centrate

Reactor

ave = 220

ave = 68

Phosphorus removal performance

0

50

100

150

200

250

300

350

400

450

11/16/2009 11/26/2009 12/6/2009 12/16/2009 12/26/2009 1/5/2010 1/15/2010 1/25/2010

Date

So

lub

le T

KN

- m

g/l

Centrate

Reactor

ave = 147

ave = 54

Kjeldahl nitrogen removal performance

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

11/16/09 11/26/09 12/06/09 12/16/09 12/26/09 01/05/10 01/15/10 01/25/10

Date

So

lub

le C

OD

- m

g/l

Centrate

Reactor

ave = 162

ave = 2395

COD removal performance

Nutrient removal from centrate by algae

• Soluble N >= 80%

• Soluble P >= 80%

• COD >= 90%

• VSS >= 30 g/m2/day

Lab-scale Evaluation

Symbiotic relationship between filamentous fungi and

microalgae in nature

• Filamentous fungi Eukaryotic microorganisms

Used in many different areas .e.g. industry, medicine,

agriculture, and basic science

Can form pellet : compact discrete masses of hyphae

Filamentous fungi and Pellets

The process of Fungi-algae pellets formation

A

D

B

C

The application of fungi-algae pellets as

immobilized cells for wastewater treatment

Fig.1.For Concentrated municipal wastewater

treatment

Fig.2.For 20X swine manure wastewater

treatment

0

20

40

60

0 12 24 36 48

Am

mo

nia

c

on

ce

ntr

ati

on

…

Time (hour)

Ammonia removal

fungi-algaepelletControl

0

20

40

60

0 12 24TP

co

nc

en

tra

tio

n

(mg

/L)

Time (hour)

TP removal

Fungi-algaePelletControl

0

500

1000

1500

2000

0 12 24

CO

D c

on

ce

ntr

ati

on

(m

g/L

)

Time (hour)

COD removal

fungi-algaepellet

020406080

100120

0 12 24 36 48

Am

mo

nia

c

on

ce

ntr

ati

on

(m

g/L

)

Time (hour)

Ammonia removal

fungi-algaepellet

Control

A

0

0.5

1

1.5

2

0 12 24 36 48

TP

co

nc

en

tra

tio

n

(mg

/L)

Time (hour)

TP removal

Fungi-algaePelletControl

B

0200400600800

10001200

0 12 24 36 48CO

D c

on

ce

ntr

ati

on

(m

g/L

)

Time (hour)

COD removal

fungi-algaepellet

Control

C

The application of fungi-algae pellets as

immobilized cell for wastewater treatment

1 2

Removing heavy metals from wastewater

Fungi-algae pellets as both feedstock and catalysts for

bio-oil production by direct thermo-chemical conversion due

to the unique properties of some metals (as catalysts)

Hydrothermal pretreatment (HP)

• Thermochemical conversion

in hot pressurized water

• Energy-efficient for

dewatering

• Protein hydrolysis

• Nutrient recycling for algae

cultivation

http://www.asiabiomass.jp/english/topics/1101_01.html

Fast Microwave Assisted Pyrolysis

(fMAP)

• Use of microwave absorbents

Bio-oils

Properties Chlorella sp. Wooda Fossil oila

Elemental analysis (wt.%)

C 65.40 56.4 83.0-87.0

H 7.84 6.2 10.0-14.0

N 10.28 0.1 0.01-0.7

O 16.48b 37.3 0.05-1.5

HHV (MJ/kg) 30.7c 21 42

Density (kg/L) 0.98d 1.2 0.75-1.0

Viscosity, at 40 oC (Pa s)

pH

0.06

7-7.5

0.04-0.20

2.5-3

2-1000

Comparison of fossil oil and bio-oils from MAP of

Chlorella sp. algae and wood

Nutrient profile of water phase after hydrothermal

liquefaction process (HLP)

PPM (mg/L) Nannochloropsis sp Chlorella sp

Total Nitrogen 10,500 6,636

Ammonia 2,200 5,673

TP 560 1,014

COD 128,400 NA

TOC 39,500 11,373

Recycling of nutrients

Pellet harvesting Fungus-algae pellet

formation

Algae cultivation

Bio-oil Refined Oil

Develop integrated process for water and nutrient

cycle

Nutrient recycle in water

phase

Water recycling

wastewaters Microalgae

Pretreatment Effluent Cultivation facility

Harvest

Biomass

Downstream processing

Liquid fuels Feed Chemicals

Effluent

Input

Process

Output

CO2

Water & nutrient recycle

Nu

trie

nt

recycle

Novel concepts of the coupled system

Life cycle environmental impacts of

wastewater-based algal biofuels

Table 2. The major energy and material flows of algae cultivation and conversion options 1

Centrate PBR Manure PBR Water open pond

Algae yield kg 1 1 1

MJ 18.8 18.8 18.8

Centrate/Manure ton 1.09 0.04 0

electricity kWh 1.70 2.04 2.47

heat MJ 13.87 13.87 13.87

Fresh water ton 0 0.19 0.24

N demand kg N 0 0 0.06

P demand kg P 0 0 0.03

CO2 injection kg 0 1.58 1.90

COD removal kg 1.685 0.304 0

TKN removal kg 0.098 0.015 0

STP removal kg 0.123 0.001 0

Net energy gain MJ -1.19 -2.41 -3.96

2

3

4

Pyrolysis + upgrading

Combustion Dry extraction +

transesterification

inputs

algae kg 1 1 1

MJ 18.8 18.8 18.8

lipid content % 20 20 20

water kg 0.22 0.14 4.40

electricity MJ 0.98 0.12

heat MJ 0.63

outputs

gasoline L 0.15

MJ 5.25

diesel L 0.14 0.21

MJ 5.06 6.51

electricity MJ 1.12 5.94 1.90

heat MJ 6.07 6.09 0.61

Net energy gain MJ -2.28 -6.77 -10.52

* Five scenarios for comparison: 1) water open pond + lipid extraction; 2) hog manure PBR + 5 lipid extraction; 3) centrate PBR + lipid extraction; 4) centrate PBR+ combustion; 5) centrate 6 PBR + pyrolysis. 7

* The net energy gain is defined as the process direct energy output 8 (algae/gasoline/diesel/electricity/heat) - process direct energy input (algae/electricity/ heat). 9

5

4

3

2 1

The use of wastewater as a nutrient source improves the

environmental performance of algae biofuels in all impact

categories.

Algae biofuels derived from centrate have better

environmental performance due to optimum nutrient

profile.

The multi-layer based bioreactor has many favorable

properties including higher algae yield, higher biomass

density, and lower land use, all of which lead to better life

cycle performance than the conventional open pond.

Large-scale implementation of this centrate-PBR system

is limited by availability of centrate.

Conclusions

Significant results

– Unique and high performance algae strains have

been developed

– Processes to effectively remove COD (chemical

oxygen demand), nitrogen, and phosphorus from

wastewaters have been developed

– New harvest techniques have been developed

– New conversion processes have been developed

– Pilot scale algae cultivation system has been

developed.

Acknowledgments: Related Group Members and Collaborators: B. Polta, J.

Willett, A. Sealock, R. Hemmingsen, R. Larkins, J. Sheehan, K. Cavender-

Bares, P. Chen, W. Zhou, M. Min, Y. Chen, L. Wang, Yecong Li, M. Mohr, X.

Ma, L. Li, H. Lei, Q. Kong, X. Wang, Y. Wan, K. Hennessy, Y. Liu, X. Lin,

Yun Li, Y. Cheng, S. Deng, Q. Chen, C. Wang, Y. Wang, Z. Du, X. Lu, R.

Zhu, A. Olson, B. Martinez, B. Zhang, J. Zhu, B. Hu, L. Schmidt, D.

Kittelson, R. Morey, D. Tiffany, X. Ye, P. Heyerdahl, ……

Funding Agencies:

Metropolitan Council

Environmental Services

Metropolitan Council

Environmental Services

Wenguang Zhou, Ph.D.

Roger Ruan, Ph.D

Center for Biorefining

Department of Bioproducts and Biosystems Engineering

University of Minnesota

1390 Eckles Ave., St. Paul, MN 55108, USA

zhouw@umn.edu

ruanx001@umn.edu

612-625-1710

http://Biorefining.cfans.umn.edu

Questions ?