Areas of Interest

• Bioenergy and Biobased Products; Waste-to-Energy

Education

• Ph.D. Bioprocess Engineering, The Hong Kong University of Science and Technology, Hong Kong (1998-2002).

• M.S. Environmental Engineering, Asian Institute of Technology, Bangkok, Thailand (1996-1997).

• B.S. (first class with honors), Civil Engineering, Malaviya National Institute of Technology, Jaipur, India (1988-1993).

Research Interests

My research interests focus on the application of physical, chemical and biological principles for the production of biofuels and valuable bio-based chemicals from agri-/forest residues and other low cost feedstocks.

I am exploring the applications of ultrasound technology in biorenewables, particularly cellulosic biomass, corn and cassava pretreatment to enhance enzymatic hydrolysis for higher ethanol yield. The ultrasound pretreatment could reduce the enzyme loading, enhance the sugar release rate and thus reduce the overall processing time and cost for biofuel production.

I am evaluating fungal process for conversion of lignocellulosic biomass to ethanol. We have successfully demonstrated that the use of white-rot - Phanerochaete chrysosporium and brown-rot - Gloeophyllum trabeum molds could convert cornstover/switchgrass into fermentable sugars during solid-state fermentation. This research has significant potential in reducing the pretreatment and the enzyme costs for cellulosic ethanol production without generation of inhibitory compounds.

I am also investigating bioenergy production potential of residues from cellulosic ethanol plants. The organic-rich stream has a potential to produce biomethane to meet the energy need of the plant. In another industrial-funded research, I am evaluating the fungal process for converting the co-products from corn-based ethanol plants into high value fungal biomass. The concept can also be applied to co-products from other biofuel and food processing industries. The protein-rich fungal biomass can be used as an animal feed due to high lysine and protein content. The fungal biomass also serves as an ideal source of chitin/chitosan. We are exploring the potential of on-site fungal enzyme production for cellulosic-ethanol plant. This will add new paradigm that could lead to consolidated bioprocessing efforts, which features cellulase production, cellulose hydrolysis, and ethanol fermentation in a single step.

I am exploring the use of innovative reactor design to enhance gas solubility during syngas fermentation. Other research arenas that I have considerable interest and experience are nisin production from soywhey, ultrasound application in food processing, biohydrogen and butanol production from agri-residues and high-rate anaerobic system for bioenergy generation.

Teaching Interests

Fundamentals of Bioprocess Engineering; Biorenewable Resources Engineering; Biomass Conversion for Energy and Chemicals; Anaerobic Biotechnology for Bioenergy Production; Renewable Energy Systems; Biobased Products and Bioprocessing.

Professional Positions and Academic Experiences

• Assistant Professor, Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa (Jan 2008-Present)

• Research Assistant Professor, Department of Civil, Construction, and Environmental Engineering; Biorenewable Resources and Technology; Biotechnology; Environmental Science; and Center for Crops Utilization Research, Iowa State University (Mar 2004-Dec 2007)

• Visiting Assistant Professor, Environmental Engineering Program, Asian Institute of Technology (AIT), Thailand (Jul-Aug 2005; May-Sep 2006; Jun-Sep 2007)

• Post-Doctoral Research Associate, Department of Civil, Construction, and Environmental Engineering, and Biorenewables, Iowa State University (Mar 2002-Feb 2004)

Professional Societies and Services

• Registered Professional Engineer (PE): State of Iowa (Registration # 17553).

• Member, Bioenergy Technology Subcommittee, Water Environment Federation.

• Member, International Water Association.

• Member, Graduate Faculty, Iowa State University.

• Member, Water Environment Federation.

Patents

• Ultrasonication in soy processing for enhanced protein and sugar yields and subsequent nisin production [US Patent No. 60/914,502].

• Fungal process for converting lignocellulosic biomass to ethanol [Provisional patent granted].

• Purification of thin stillage from dry corn milling with fungi [Provisional patent granted].

New Release/Press Clippings:

• UH Tests Ethanol Waste as Animal Feed, Star Bulletin, Vol. 13, Issue 174- Sunday, June 22, 2008 http://starbulletin.com/2008/06/22/news/story02.html

• 
  Hawaii University Tests Vinasse as Animal Feed http://www.allaboutfeed.net/news/id102-55718/hawaii_uni_
  tests_vinasse_as_animal_feed.html

• Iowa State researchers use fungus to improve corn-to-ethanol process http://www.eurekalert.org/pub_releases/2008-05/isu-isr052708.phphttp://www.newswise.com/articles/view/541146/
  

• Ultrasound Pretreatment of Biological Sludge to Enhance Bioenergy Production. IWA Specialized Group on Sludge Management. March 2007

• Researchers Improve Soy Processing by Boosting Protein and Sugar Yields. ScienceDaily. http://www.sciencedaily.com/releases/2007/02/070215133344.htm

• From Corn to Ethanol in a Jiffy. BusinessWeek, pp 107, Jul 2006. http://www.businessweek.com/magazine/content/06_27/c3991080.htm

• Ultrasonics Boosts Release Rates of corn Sugars for Ethanol Production. ScienceDaily. http://www.sciencedaily.com/releases/2006/06/060601213717.htm

• Biotechnology Update. http://www.biotech.iastate.edu/biotech_update/PDF/jun06.pdf

• Turning Corn Fiber into Ethanol. http://www.physorg.com/news68392594.html

• Fast Corn-to-Ethanol Approach Discover. SHORTLINER, Vol. LVI (14), Aug 2006.

Awards

• 2008 R & D 100 Award for Fungal Process for Ethanol Plant Stillage Treatment .

• IWA Project Innovation Award 2008. .

• American Association of Environmental Engineering Excellence Award-2008: University Research Grand Prize, Washington, D.C. "Value-Added Products from Dry-Grind Corn Milling Stillage by Fungal Processing." (With J (Hans) van Leeuwen, Mary Rasmussen and Anthony Pometto).

• UIA 2008 Graduate Research Award, Washington, D.C. "Ultrasound Enhanced Glucose Release from Corn in Ethanol Plants" (Awarded to advisee: Melissa Montalbo).

Publications

Book

• Khanal, S. K. Anaerobic Biotechnology for Energy Production: Principles and Applications.
  John Wiley & Sons and Blackwell Publishing. Expected Publication Date: August 2008.

Refereed Journals

• Sindhuja, S., Khanal, S. K., Pometto, A. L., Jin, B. and Van Leeuwen, J. Use of microfungi for production of high value fungal by-products: A review. Critical Reviews in Environmental Science and Technology (accepted).

• Nitayavardhana, S., Rakshit, S. K., Grewell, D. Van Leeuwen, J. and Khanal, S. K. Ultrasound pretreatment of cassava chips to enhance sugar release for subsequent ethanol production. Biotechnology and Bioengineering (accepted).

• Shrestha, P., Rasmussen, M., Khanal, S. K., Pometto, A.L. and Van Leeuwen, J. Solid-state fermentation of corn fiber by Phanerochaete chrysosporium and subsequent fermentation of hydrolysate into ethanol. Journal of Agriculture and Food Chemistry (accepted).

• Khanal, S. K., Montalbo, M., Van Leeuwen, J., Srinivasan, G. and Grewell, D. 2007. Ultrasound enhanced glucose release from corn in ethanol plants. Biotechnology and Bioengineering, 98 (5), 978-985.

• Ho, J., Khanal, S. K. and Sung, S. (2007). Anaerobic membrane bioreactor for treatment of synthetic municipal wastewater at ambient temperature. Water Science and Technology, 55 (7):79-86.

• Khanal, S. K., Grewell D, Sung, S. and Van Leeuwen, J. (2007). Ultrasound applications in wastewater sludge pretreatment: A review. Critical Reviews in Environmental Science and Technology, 37 (4): 277-313.

• Khanal, S. K., Xie, B., Ong, S. K., Thompson, M. L., Sung, S. and Van Leeuwen, J. (2006). Fate, transport and biodegradation of natural estrogens in the environment and engineered systems-A review. Environmental Science and Technology, 40 (21): 6537-6546.

• Chen, W.-H., Chen, S.-Y., Khanal S. K. and Sung, S. (2006). Kinetic study of biological hydrogen production by anaerobic fermentation. International Journal of Hydrogen Energy 31(15): 2170-2178.

• Akin, B., Khanal, S. K., Sung, S., Grewell, D. and van Leeuwen, J. (2006).Ultrasound pre-treatment of waste activated sludge: effect of specific energy input and total solids on sludge disintegration. Water Science and Technology –Water Supply, 6(6): 35-42.

• Khanal, S. K., and Huang, J.-C. (2006). Online oxygen control for sulfide oxidation in anaerobic treatment of high sulfate wastewater. Water Environment Research, 78 (4): 397-408.

• Khanal, S. K., Chen, W.-H., Li, L. and Sung, S. (2006). Biohydrogen production in continuous flow reactor using mixed microbial culture. Water Environment Research, 78 (2): 110-117.

• Foulkes, B., Khanal, S. K. and Sung, S. (2006). Bioleaching of zinc and copper from anaerobically digested swine manure: effect of sulfur levels and solid contents. Water Environment Research, 78(2): 202-208.

• Jasti, N., Khanal, S. K., Pometto, A. L. and Van Leeuwen, J. (2006). Fungal treatment of corn processing wastewater in an attached growth system. Water Science and Practice, 1 (3): 1-8.

• Khanal, S. K. and Huang, J.-C. (2005). Effect of high influent sulfate on anaerobic wastewater treatment. Water Environment Research, 77(7): 3037-3046.

• Khanal, S. K., Chen, W.-H., Li, L. and Sung, S. (2004). Biological hydrogen production: effects of pH and intermediate products. International Journal of Hydrogen Energy, 29(11): 1123-1131.

• Huang, J.-C. and Khanal, S. K. (2004). Treatment of high sulfate and high strength wastewater in a single stage anaerobic reactor. Water Science and Technology-Water Supply, 4 (1): 35-45.

• Khanal, S. K. and Huang, J.-C. (2003). Anaerobic treatment of high sulfate wastewater with oxygenation to control sulfide toxicity. J. Environmental Engineering, ASCE, 129(12): 1104 1111.

• Khanal, S. K., Shang, C. and Huang, J.-C. (2003). Use of oxidation-reduction potential (ORP) to control oxygen dosing for online sulfide oxidation in anaerobic treatment of high sulfate wastewater. Water Science and Technology, 47(12): 183-189.

• Khanal, S. K. and Huang, J.-C. (2003). ORP based oxygenation for sulfide control in anaerobic treatment of high sulfate wastewater. Water Research, 37(9): 2053-2062.

Refereed Conference Proceedings (speaker denoted by "*")

• Khanal, S. K., Montalbo, M*., Van Leeuwen, J., Srinivasan, G. and Grewell, D. Ultrasonic enhanced liquefaction and saccharification of corn for biofuel production. ASABE Annual International Meeting (AIM), Jun 17-20, Minneapolis, MN.

• Karki, B*., Lamsal, B. P., Grewell, D., Van Leeuwen, J. and Khanal, S. K. Ultrasonication in soy processing for enhanced protein and sugar yields and subsequent bacterial nisin production. ASABE Annual International Meeting (AIM), Jun 17-20, Minneapolis, MN.

• Rasmussen, M*., Khanal, S. K., Pometto, A. L. and Van Leeuwen, J. Thin stillage treatment from dry grind ethanol plants with fungi. ASABE Annual International Meeting (AIM), Jun 17-20, Minneapolis, MN.

• Shrestha, P*., Vincent, M., Khanal, S. K., Pometto, A. L. and Van Leeuwen, J. Fungal fermentation of corn fiber to enhance ethanol production. ASABE Annual International Meeting (AIM), Jun 17-20, Minneapolis, MN.

• Akin, B*., Khanal, S. K., Sung, S., Grewell, D. and Van Leeuwen, J. Effect of total solids concentration on ultrasonic disintegration of waste activated sludge. IWA Specialized Conference – Facing Sludge Diversities: Challenges, Risks, and Opportunities, Mar 28-30, 2007, Antalya, Turkey.

• Khanal, S. K*., Isik, H., Sung, S. and Van Leeuwen, J. Ultrasound pretreatment of waste activated sludge: evaluation of sludge disintegration and aerobic digestibility. IWA World Water Congress and Exhibition, Sep 10-14, 2006, Beijing, China.

• Khanal, S. K*., Isik, H., Sung, S. and Van Leeuwen, J. Ultrasonic conditioning of waste activated sludge for enhanced aerobic digestion. IWA Specialized Conference - Sustainable Sludge Management: State of the Art, Challenges and Perspectives, May 29-31, 2006, Moscow, Russia.

• Khanal, S. K*., Isik, H. and Sung, S. Effects of ultrasound pretreatment on aerobic digestibility of thickened waste activated sludge. 7th Specialized Conference on Small Water and Wastewater Systems, Mar 7 -10, 2006, Mexico City, Mexico.

• Huang, J.-C*. and Khanal, S. K. Biological odor control technology for high sulfate wastes. In Proceedings of 4th Symposium on Anaerobic Digestion of Solid Waste, Aug 31- Sept 2, 2005, Cohenhagen, Denmark.

• Jasti, N*., Khanal, S. K., Pometto, A. L. and Van Leeuwen, J. Attached growth fungal system for food processing wastewater treatment and high value protein recovery. In CD-ROM Proceedings of 78th Annual Conference & Exposition (WEFTEC), Oct 29 - Nov 2, 2005, Washington, D.C.

• Jasti, N*., Khanal, S. K., Pometto, A. L. and Van Leeuwen, J. Treatment of food processing wastewater using attached growth fungal system. In CD-ROM Proceedings of 1st IWA-ASPIRE (Asia Pacific Regional Group) Conference & Exhibition, Jul 10-15, 2005, Singapore.

• Huang, Y.-T., Chen, S.-Y., Khanal, S. K*. and Sung, S. Biological hydrogen production potential of cellulose-derived sugars. In CD-ROM Proceedings of 1st IWA-ASPIRE (Asia Pacific Regional Group) Conference & Exhibition, Jul 10-15, 2005, Singapore.

• Wongkarnka, M., Khanal, S. K*., Eliosov, B., Leeuwen, J. and Ellis, T.G (2004). Production of aerobic yeast from industrial process stream. In CD-ROM Proceedings of 1st IWA-ASPIRE (Asia Pacific Regional Group) Conference & Exhibition, Jul 10-15, 2005, Singapore.

• Khanal, S. K.* and Huang, J.-C. (2003). Treatment of high sulfate wastewater in upflow anaerobic filter. In CD-ROM Proceedings of Asian WaterQual 2003, Oct 19-23, 2003, Bangkok, Thailand.

• Li, C., Ho, J. H., Khanal, S. K. and Sung, S*. (2003). Temperature-phased anaerobic digestion (TPAD) of food waste together with wax-coated cardboard. In CD-ROM Proceedings of Asian WaterQual 2003, Oct 19-23, 2003, Bangkok, Thailand.

• Sung, S., Khanal, S. K., Chen, W.-H*. and Cao, Q. (2003). Bioconversion of sulfide to elemental sulfur in trickling filter. In CD-ROM Proceedings of Asian WaterQual 2003, Oct 19-23, 2003, Bangkok, Thailand.

Technical Presentations (Without Proceedings)

• Sustainable Bioenergy: Focus on the Future of Biofuels and Chemicals, Apr 13-14, 2006, University of Illinois, Urbana-Champaign, Urbana, IL.

• BIO Conference on Biobased Industry Outlook, Aug 29-30, 2005, Iowa State University Ames, IA.

• Biotechnology Byproducts Consortium Symposium, Oct 27-28, 2004, University of Iowa, Iowa City, IA.

• US Department of Energy Workshop on Hydrogen Production via Direct Fermentation, Jun 9, 2004, Baltimore, MD.

• BIO Conference on Biobased Industry Outlook, Mar 7-8, 2004, Iowa State University, Ames, IA.

• Water Environment Federation: Charting the Future Direction of Bioenergy Technologies, Aug 14-15, 200, Tulane University, New Orleans, LA.

• US Department of Energy Hydrogen and Fuel Cells, 2003 Annual Merit Review, May 19- 22, 2003, Berkeley, CA.

• Iowa Academy of Science, 115th Annual Meeting, Apr 25 - 26, 2003, Des Moines, IA.

• Water Environment Federation: WEFTEC 75th Annual Technical Exhibition and Conference, Sep 28 - Oct 2, 2002, Chicago IL.

Invited/ Guest Speaker

• The Fifth International Starch Technology Conference, University of Illinois, Urbana-Champaign, IL (Jun 3 – 6, 2007). “Energy issue.”

• Cornell University, Ithaca, NY (May 9-11, 2007). “Renewable energy from agro-based feedstocks: A key to sustainability.”

• Ohio State University, Columbus, OH (Feb 5, 2007). “Microbial bioconversion of agro-based feedstocks to bioenergy and biobased products.”

• Joint Graduate School of Energy and Environment, King Mongkut’s University of Technology, Bangkok, Thailand (Jan 17, 2007). “Bioenergy and value-added bioproducts from agro-based feedstock: An emerging research frontier.”

• Iowa State University, Biorenewables Meeting (Dec 19, 2006). “Bioenergy production from cellulose-to-ethanol plants-derived stillage.”

• Advanced Science Institute, Hong Kong University of Science and Technology, Hong Kong (Sep 20, 2006). “Ultrasonic pretreatment of waste activated sludge.”

• Beijing Normal University, Beijing (Sep 14, 2006). “Recovery of high-value fungal bio-products from wet corn milling liquid stream.”

• The Society for Engineering in Agricultural, Food, and Biological Systems, Society of Manufacturing Engineering, Society of Mechanical Engineering, Society of Automotive Engineering, Waterloo, IA (Nov 10, 2005), “Alternative Energy: Energy Engineering”

• Department of Agricultural and Biosystems Engineering, North Dakota State University, Fargo, ND (Aug 31, 2005). “Converting agri-residues to biofuels and bio-products.”

• Biobased Industry Outlook Conference, Ames, IA (Aug 29, 2005). “Anaerobic digestion of thin stillage to produce methane and Class-A biosolids.”

• Haceteppe University, Ankara, Turkey (Aug 17, 2005). “Anaerobic membrane bioreactor for municipal sewage treatment.”

• Asian Institute of Technology, Bangkok, Thailand (Aug 11, 2005). “Integrated Waste Biomass-based Biorefinery.”

• Malaysia University of Science and Technology, Malaysia (Jul 15, 2005). “Emerging research frontiers: coupling waste treatment with bio-products and bioenergy recovery.”

• Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA (Mar 24, 2005). “Bioconversion for sustainability.”

• Dept. of Civil Engineering, University of Canterbury, Christchurch, New Zealand (Dec 2003). “Anaerobic biotechnology for waste treatment and resource recovery.”

• Department of Civil and Environmental Engineering, University of Missouri-Columbia, MO, (Oct 31, 2002). “Oxygenated anaerobic treatment of high sulfate wastewater.”