HARVESTING MICROALGAE (CHLAMYDOMONAS

REINHARDTII) FOR BIOFUEL PRODUCTION USING

WASTEWATER TREATMENT TECHNIQUES

By Michael Fuad

Potential of Algae

http://geography.about.com/library/blank/blxusa.htm

Potential of Algae

http://geography.about.com/library/blank/blxusa.htm

Potential of Algae

Complete Process Producing Biofuel

Complete Process Producing Biofuel

Complete Process Producing Biofuel

Complete Process Producing Biofuel

Complete Process Producing Biofuel

Complete Process Producing Biofuel

Esterification produces biofuels

What is the problem?

• Algae cost $20.00/gallon of biofuel• Furthermore, a significant part of that

production cost is associated with harvesting microalgae

Background

• 10 µm

http://algae.tcoalternativefuels.com/wp-content/uploads/2008/05/chlorellasp_microscope.jpg

10 µm

Background

http://www.steve.gb.com/images/science/centrifugation.png

Background

Alternative Harvesting Methods:1. Ultrasonic separation—Bosma et al. (2003)

Background

Alternative Harvesting Methods:1. Ultrasonic separation2. Froth flotation—Csordas et al. (2004)

Background

Alternative Harvesting Methods:1. Ultrasonic separation2. Froth flotation3. Flocculation

Background

http://globalpolyglu.com/treatment1-2.html

Background

http://globalpolyglu.com/treatment1-2.html

Background

http://globalpolyglu.com/treatment1-2.html

Background

• Water and Wastewater Technology by Hammer and Hammer (1996) explained flocculation

Background

• A Lee et al. (2007)—algae are negatively charged microparticles

Hypothesis

• I hypothesized that chemicals used in wastewater treatments could be used to flocculate microalgae

Background

• Knuckey et al. (2006)—identified factors that affect flocculation, i.e. pH and dosage

Goals

1. Determine if flocculation is an effective alternative to centrifugation for harvesting C. reinhardtii from suspension; and

2. Identify factors that optimize flocculation of C. reinhardtii in order to achieve harvesting efficiency that is similar to or better than centrifugation in preparation for biofuel production.

Procedure

• Measure effectiveness of harvesting by flocculation using spectrophotometer, measuring optical density (absorbance)

Materials: Ionic Compounds

1. Aluminum sulfate—Al2(SO4)3 2. Ferric chloride—FeCl3

3. Calcium carbonate—CaCO3

4. Ammonium sulfate—(NH4)2SO4

Materials: Polyacrylamides

Results

Results

0

0.2

0.4

0.6

0.8

1

pH 7.00pH 3.00

Ionic Compound

Floc

cula

tion

Effici

ency

Al2(SO4)3 FeCl3 CaCO3 (NH4)2SO4

Results

0

0.2

0.4

0.6

0.8

1

pH 7.00pH 3.00

Ionic Compound

Floc

cula

tion

Effici

ency

Al2(SO4)3 FeCl3 CaCO3 (NH4)2SO4

Results

0

0.2

0.4

0.6

0.8

1

pH 7.00pH 3.00

Ionic Compound

Floc

cula

tion

Effici

ency

Al2(SO4)3 FeCl3 CaCO3 (NH4)2SO4

Results: pH 3.00

1 2 3 4 5 6 7 8 9 10 11 12 130.00

0.20

0.40

0.60

0.80

1.00

Polyacrylamide Number

Floc

cula

tion

Effici

ency

Results: pH 3.00

1 2 3 4 5 6 7 8 9 10 11 12 130%

20%

40%

60%

80%

100%

Polyacrylamide Number

Floc

cula

tion

Effici

ency

Results: pH 3.00

1 2 3 4 5 6 7 8 9 10 11 12 130%

20%

40%

60%

80%

100%

Polyacrylamide Number

Floc

cula

tion

Effici

ency

Conclusions

• Flocculation effectively harvests microalgae• The optimum flocculation technique is to use

Clarifloc Polyacrylamide C-6288 at a pH of 3.00 and a dosage of 0.025 g flocculant/g dry algae

• Since flocculation is more efficient than centrifugation, flocculation is a less expensive method of harvesting microalgae

Limitations

• My research limited to a single species of algae

• Flocculation factors might vary for different algae species

• Effect of chemicals on environment is experimentally unknown. However, theoretically, flocculation is safe for environment

Future Work

• Engineer a continuous flocculation system

• Apply the flocculation techniques to other microalgae species with potential

http://brator.sinto.co.jp/global/picture/dspirast.jpg

Acknowledgements

• Dr. Roger Ruan• Science Research Team• Mrs. Fruen• Mr. Hall

http://www.bioeconomyconference.org/07%20Images/ruan.jpg

HARVESTING MICROALGAE (CHLAMYDOMONAS

REINHARDTII) FOR BIOFUEL PRODUCTION USING

WASTEWATER TREATMENT TECHNIQUES

By Michael Fuad