Proceedings of the 2007 National Conferenceon Environmental Science and Technology

Godfrey A. Uzochukwu

Proceedings of the 2007National Conferenceon Environmental Scienceand Technology

123

EditorGodfrey A. UzochukwuWaste Management InstituteNorth Carolina A&T State University261 Carver Hall AnnexGreensboro NC 27411USAuzo@ncat.edu

ISBN 978-0-387-88482-0 e-ISBN 978-0-387-88483-7DOI 10.1007/978-0-387-88483-7

Library of Congress Control Number: 2008937810

c© Springer Science+Business Media, LLC 2009All rights reserved. This work may not be translated or copied in whole or in part without the writtenpermission of the publisher (Springer Science+Business Media, LLC, 233 Spring Street, New York,NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use inconnection with any form of information storage and retrieval, electronic adaptation, computersoftware, or by similar or dissimilar methodology now known or hereafter developed is forbidden.The use in this publication of trade names, trademarks, service marks, and similar terms, even ifthey are not identified as such, is not to be taken as an expression of opinion as to whether or notthey are subject to proprietary rights.

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Preface

The purpose of the Third National Conference on Environmental Science andTechnology, which was held in Greensboro, North Carolina on September 12–14,2007 was to address pollution prevention, solutions, and research needs and fosterrelationships that could result in partnerships needed to protect and sustain the en-vironment and improve the quality of life. The following topics are included in thisbook: Pollution Prevention, Fate and Transport of Contaminants, Bioremediation,Bio-processing, Innovative Environmental Technologies, Global Climate Change,and Environmental Justice and Ethics.

Several discussions about Global Climate Change, Pollution Prevention, Envi-ronmental Justice and Ethics among Godfrey A. Uzochukwu (Waste ManagementInstitute, North Carolina A & T State University), Sherry Southern and Jeffrey Alli-son (DOE—Savannah River Site), Thomas Parker (CDM), Glennis Nelson (CDM),Jason Callaway (Allied Waste), Steve Roland (O’Brien & Gere), Marv Richard-son (O’Brien & Gere) and Rick Crume (US Environmental Protection Agency)set the stage for the Third National Conference on Environmental Science andTechnology. The following persons served on the Executive Conference Commit-tee: G.B. Reddy (Professor of Environmental Microbiology), Shoou-Yuh Chang(Professor of Environmental Engineering), Vinayak Kabadi (Professor of Chemi-cal Engineering), Keith Schimmel (Associate Professor of Chemical Engineering),Emmanuel Nzewi (Professor and Director of Civil and Environmental Engineer-ing), Stephanie Luster-Teasley (Assistant Professor of Environmental Engineering)and Godfrey A. Uzochukwu (Professor and Director, Waste Management Insti-tute). These individuals approved the conference theme – Environmental Scienceand Technology. The authors of presentations accepted for the Conference wereasked to prepare a six-page (maximum) paper, following the guidelines developedby Springer. Full papers were peer reviewed and recommended for publication inthe proceedings.

The following agencies are thanked for their financial support of the con-ference; NOAA Interdisciplinary Environmental Technology Cooperative ScienceCenter); NSF Science & Technology Center; Allied Waste Services, O’Brien &Gere; US Department of Energy (Savannah River Site); US Environmental Protec-tion Agency; North Carolina A&T State University (Waste Management Institute,DOE Chair of Excellence in Environmental Disciplines, School of Agriculture and

v

vi Preface

Environmental Sciences and College of Engineering. In addition, the hard workof Cheryl Bowers, Allyson Alston, Sheena Shearin, Cecilia Worthington, Patri-cia White, Patricia O’Connor, Gloria Hughes, Furmose Gomez and Jesse Davis isgratefully acknowledged. We would like to express our thanks to Springer staff forassembling this book.

Special thanks go to the following conference keynote speakers: Stanley F. Battle,Chancellor, North Carolina A&T State University; Gregory Green, US Environ-mental Protection Agency, Research Triangle Park; Sherry Southern, United StatesDepartment of Energy and Thomas Parker, CDM.

The conference co-sponsors, Springer and other supporting organizations did notreview the published materials in this book. Their support for the conference is notan endorsement of the content.

Greensboro, NC, USA Godfrey A. UzochukwuGreensboro, NC, USA Keith SchimmelGreensboro, NC, USA Shoou-Yuh ChangGreensboro, NC, USA Vinayak KabadiGreensboro, NC, USA Stephanie Luster-TeasleyGreensboro, NC, USA Gudigopuram B. ReddyGreensboro, NC, USA Emmanuel Nzewi

Contents

Part I Bioprocessing

Synthesis of Poly(L(+) Lactic Acid) by Polycondensation Methodin Solution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Jian Zhang, Parakalan Krishnamachari, Jianzhong Lou,and Abolghasem Shahbazi

The Feasibility of Using Cattails from Constructed Wetlandsto Produce Bioethanol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9Katherine Suda, Abolghasem Shahbazi, and Yebo Li

Significance of Bile Salt Tolerant Lactobacillus reuteri . . . . . . . . . . . . . . . . . . 17Siham A. Ahmed, Salam A. Ibrahim, Chyer Kim,and Abolghasem Shahbazi

The Effect of Insulin from Jerusalem Artichoke (Helianthus tuberosus)Extract on Growth and Viability of Lactobacillus salivariusin Fermented Milk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Souod R. Alani, Angela M. Fraser, Mustafa A. Alsharafani,Farouk F. Al-Nouri, and Salam A. Ibrahim

Lactic Acid Production from Apple Skin Waste by Immobilized Cellsof Lactobacillus reuteri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31Moussa M.E. Salem, Salam A. Ibrahim, Chyer Kim, Chung W. Seo,Abolghasem Shahbazi, and Amer AbuGhazaleh

Part II Bioremediation

Cu and Zn Uptake Inhibition by PAHs as Primary Toxicity in Plants . . . . . 41Zarhelia Carlo-Rojas and Wen-Yee Lee

Metagenomic Environmental Assessment of Aquatic Ecosystems . . . . . . . . 47Parke A. Rublee, Vincent C. Henrich, and Michael M. Marshall

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Part III Environmental Justice and Ethics

Water Quality in an Environmental Justice Communityin Durham, NC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55Blakely Adair, John J. Bang, Yolanda B. Anderson, Saundra F. DeLauder,Marcia Bradshaw, Marion Lamberth, Faustina Meheux, Rakesh Malhotra,Roy Fortmann, Peter Egeghy, Ronald Williams, and Donald Whitaker

The Impact of Social Capital on Environmental Risk Reductionin Moncure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61John J. Bang, Yolanda B. Anderson, Saundra F. DeLauder, Marcia Bradshaw,Faustina Meheux, Rakesh Malhotra, Roy Fortmann, Peter Egeghy,Ronald Williams, and Donald Whitaker

Air Quality Issues for an Aging Population . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Richard V. Crume, Kathleen E. Sykes, and Yoko S. Crume

Environmental Pollution, Race and Place: Research and PolicyImplications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77Ibipo Johnston-Anumonwo

Financial Reporting of Environmental Risks and Liabilities . . . . . . . . . . . . . 85Gwendolyn McFadden-Wade, Jean T. Wells, and Diana R. Robinson

Oak Biodiesel: State Building and Fire Codes Affecting BiodieselManufacturing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91Myra M. Shird and Regina M. Williams

The Ecological Effects of Salt Water Intrusion on the AgricultureIndustry After Hurricane Katrina . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97Vereda Johnson Williams

Municipal Wastewater Concentrations of Pharmaceuticaland Xeno-Estrogens: Wildlife and Human Health Implications . . . . . . . . . . 103Maxine Wright-Walters and Conrad Volz

Challenges in the Devolution of Environmental Health Service Deliveryin South Africa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115Renay Van Wyk

A Review of Health and Hygiene Promotion as Part of SanitationDelivery Programmes to Informal Settlements in the Cityof Cape Town (South Africa) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121Renay Van Wyk

Contents ix

Pollution, Environmental Justice, and the North CarolinaPork Industry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127Osei Yeboah, Terrence Thomas, Timothy Foster, and Edward Fosu

Reducing Community Exposure to Toxics: A Critical Componentin Building Healthy and Sustainable Communities . . . . . . . . . . . . . . . . . . . . . 139Robert C. Wingfield

Environmental Ethics of Health Mission To Enugu Nigeria . . . . . . . . . . . . . . 149Godfrey A. Uzochukwu, Mary E. Uzochukwu, and Ethelbert Odo

Part IV Fate and Transport of Contaminants

Use of Kalman Filter and Particle Filter in a One DimensionalLeachate Transport Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157Shoou-Yuh Chang and Sikdar M.I. Latif

Organic Pollutant Transport in Groundwater Using Particle Filter . . . . . . . 165Shoou-Yuh Chang and Xiaopeng Li

Modeling the Sorption Behavior of Aromatic Amine Onto SedimentUnder Acidic Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173Shihua Chen and Marianne C. Nyman

Radioactive Contaminanant Transport in Subsurface PorousEnvironment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181An Jin and Shoou-Yuh Chang

Transport and Degradation of a Trichloroethylene Plume Withina Stream Hyporheic Zone . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189John B. Williams, Gary Mills, Daniel Barnhurst, Sherry Southern,and Noelle Garvin

Part V Global Climate Change

Using a Spoken Diary and Heart Rate Monitor in Modeling HumanExposure to Airborne Pollutants for EPA’S Consolidated HumanActivity Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197Curry I. Guinn and Daniel J. Rayburn Reeves

Proposal for Focus Shift in Addressing Climate Changeand Environmental Assesment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205Gennadyi Gurman

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Sensor Webs in Digital Earth: Monitoring Climate Change Impacts . . . . . . 211Matt Heavner, Rob Fatland, Eran Hood, Cathy Connor, Tracy Lee Hansen,Mary Sue Schultz, Tom LeFebvre, and Albert Esterline

Thermal Characterization of Biodegradable Poly (Lactic Acid)/ClayNanocomposites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219Parakalan Krishnamachari, Jian Zhang, Jizhong Yan, Abolghasem Shahbazi,Leonard Uitenham, and Jianzhong Lou

Tools for Carbon Management: Potential Carbon Footprint ReductionThrough Fuel Switching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227Parikhit Sinha and David M. Cass

Coral Disease and Global Climate Change . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233Garriet W. Smith and Marie-Ange Smith

Climate Change, Drought, and Wetland Vegetation . . . . . . . . . . . . . . . . . . . . 239Brant W. Touchette and Sara E. Steudler

Dynamics of Soil Organic Nitrogen and its Functions in Soil CarbonStabilization Processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245Xianzhi Song

Greenhouse Gas Mitigation Potential of Corn Ethanol: Accountingfor Corn Acreage Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251Lyubov A. Kurkalova, Silvia Secchi, and Phillip W. Gassman

Comparative Effects of Sea Level Rise Versus Hurricane Eventon Coastal Erosion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259John B. Williams

Global Warming in Asheville, North Carolina . . . . . . . . . . . . . . . . . . . . . . . . . 265George Ford, William McDaniel, and Aaron Ball

Part VI Innovative Environmental Technology and Sensors

Tuckaseegee Watershed Observatory: A Collaborative EnvironmentalResearch Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271Brian P. Howell, Roger Clapp, Jeff Marston, Chris Donaldson,and Brent McCoy

Encapsulation of Potassium Permanganate Oxidant in Polymers . . . . . . . . . 279Stephanie Luster-Teasley, David Price, and Dereje Worku

Contents xi

C. Elegans Chemotaxis and Reproduction Following EnvironmentalExposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285Mulumebet Worku and Carresse Gerald

Storing Weather Data and Dissemination Via the Web . . . . . . . . . . . . . . . . . . 293Kawana O. Fuller and Austin Frazier

Rapid and Simple Method for the Encapsulation of Lactobacillus reuteriin the Production of Lactic Acid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301Salam A. Ibrahim, Somphavanh Phetsomphou, Chyer Kim, AbolghasemShahbazi, Chung W. Seo, Amer AbuGhazaleh, and Moussa M.E. Salem

Part VII Pollution Prevention/Solvents and Processes

Analysis of Partition Coefficients and Ternary Liquid-LiquidEquilibrium Data for Highly Non-Ideal Systems . . . . . . . . . . . . . . . . . . . . . . . 311Wahid Islam and Vinayak Kabadi

Application of Chitosan in Remediation of Dyes . . . . . . . . . . . . . . . . . . . . . . . . 319Gbekeloluwa B. Oguntimein, Olatunde Animashaun, and Ivie Okpere

An Apparatus for Density and VLE Measurements for Gas-LiquidSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325Rashawn K. Washignton and Vinayak N. Kabadi

MSE Walls in Solid Waste Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331Thomas M. Yanoschak

Study of the Molecular Weight Dependence of Glass TransitionTemperature for Amorphous Poly(L-Lactide) by Molecular DynamicsSimulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339Jian Zhang, Jizhong Yan, Leonard Uitenham, and Jianzhong Lou

Channel Catfish Estrogenicity and Sewer Overflows; Implicationsfor Xenoestrogen Exposure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345Conrad Daniel Volz, Frank Houghton, Nancy Sussman, Diana Lenzner,Devra Davis, Maryann Donovan, Talal El Hefnawy, and Patricia Eagon

Sorption and Desorption of Nitrogen and Phosphorus by Zeoliteand Shale . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353Johnsely S. Cyrus and G.B. Reddy

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365

Contributors

Amer AbuGhazaleh Southern Illinois University, Carbondale, IL, USA

Blakely Adair North Carolina Central University, Durham, NC, USA

Siham A. Ahmed Department of Family and Consumer Sciences, North CarolinaA&T State University, Greensboro, NC 27411-1064, USA

Souod R. Alani Department of 4H Youth Development and Family & ConsumerSciences, North Carolina State University, Raleigh, NC 27695, USA

Farouk F. Al-Nouri Food Sciences & Biotechnology Department, College ofAgriculture, Baghdad University, Iraq

Mustafa A. Alsharafani Ministry of Science & Technology, P.O. Box 765,Baghdad, Iraq

Yolanda B. Anderson North Carolina Central University, Durham, NC, USA

Olatunde Animashaun Department of Medical Technology, Morgan StateUniversity, Baltimore, Maryland, 21251, USA

Aaron Ball Western Carolina University, Cullowhee, NC, USA

John J. Bang North Carolina Central University, Durham, NC, USA

Daniel Barnhurst Washington Savannah River Corporation, Aiken, SC, USA

Marcia Bradshaw North Carolina Central University, Durham, NC, USA

Zarhelia Carlo-Rojas Environmental Science and Engineering PhD (ESE)Program UTEP, El Paso, TX, USA

David M. Cass O’Brien & Gere, Blue Bell, Pennyslvania, USA

Shoou-Yuh Chang North Carolina A&T State University, Greensboro, NC,27411, USA

S. Chen Department of Civil and Environmental Engineering, MRC 319,Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA

Roger Clapp WATR, Bryson City, NC, USA

xiii

xiv Contributors

Cathy Connor University of Alaska Southeast, Juneau, Alaska, USA

Richard V. Crume U.S. EPA, Research Triangle Park, NC, USA

Yoko S. Crume NC A&T State University, Greensboro, NC, USA

Johnsely S. Cyrus Department of Natural Resources and Environmental Design,North Carolina A&T State University, Greensboro, NC 27411, USA

Devra Davis University of Pittsburgh Cancer Institute, Center for EnvironmentalOncology, Pittsburgh PA, USA; University of Pittsburgh, Graduate School ofPublic Health, Pittsburgh PA, USA

Saundra F. DeLauder North Carolina Central University, Durham, NC, USA

Chris Donaldson WCU, Cullowhee, NC, USA

Maryann Donovan University of Pittsburgh Cancer Institute, Center forEnvironmental Oncology, Pittsburgh PA, USA; School of Medicine, University ofPittsburgh, Pittsburgh PA, USA

Patricia Eagon University of Pittsburgh Cancer Institute, Center for Environmen-tal Oncology, Pittsburgh PA, USA; Veterans Research Foundation, Veterans AffairsMedical Center, Pittsburgh PA USA; School of Medicine, University of Pittsburgh,Pittsburgh PA, USA

Peter Egeghy U.S. EPA National Exposure Research Laboratory, RTP, NC, USA

Albert Esterline NCA&T, Greensboro, NC, USA

Rob Fatland Vexcel/Microsoft Geospatial Solutions, Boulder, CO, USA

George Ford Western Carolina University, Cullowhee, NC, USA

Roy Fortmann U.S. EPA National Exposure Research Laboratory, RTP, NC, USA

Timothy Foster North Carolina A&T State University, Greensboro, NC, USA

Edward Fosu North Carolina A&T State University, Greensboro, NC, USA

Angela M. Fraser Department of 4H Youth Development and Family & ConsumerSciences, North Carolina State University, Raleigh, NC 27695, USA

Austin Frazier North Carolina A&T State University, Greensboro, NC, USA

Kawana O. Fuller Department of Computer Science, North Carolina A&TState University, Greensboro, NC 27411, USA

Noelle Garvin University of Georgia SREL, Aiken, SC, USA

Phillip W. Gassman Iowa State University, Ames, IA, USA

Carresse Gerald North Carolina A&T State University, Greensboro, NC, USA

Curry I. Guinn University of North Carolina Wilmington, USA

Gennadyi Gurman Queens Botanical Garden, Flushing, NewYork, USA

Contributors xv

Tracy Lee Hansen NOAA Earth System Research Lab, Boulder, CO, USA

Matt Heavner University of Alaska Southeast, Juneau, Alaska, USA

Talal El Hefnawy University of Pittsburgh Cancer Institute, Center forEnvironmental Oncology, Pittsburgh PA, USA

Vincent C. Henrich The University of North Carolina at Greensboro, Greensboro,NC, USA

Eran Hood University of Alaska Southeast, Juneau, Alaska, USA

Frank Houghton Veterans Research Foundation, Veterans Affairs Medical Center,Pittsburgh PA, USA

Brian P. Howell Western Carolina University, Cullowhee, NC, USA

Salam A. Ibrahim Department of Family and Consumer Sciences, Food andNutritional Sciences, North Carolina A&T State University, Greensboro, NC27411-1064, USA

Wahid Islam Department of Chemical Engineering, North Carolina A&T StateUniversity, Greensboro, NC, USA

A. Jin North Carolina A&T State University, Greensboro, NC 27411, USA

Ibipo Johnston-Anumonwo State University of New York, Cortland, New York,USA

Vinayak Kabadi Department of Chemical Engineering, North Carolina A&TState University, Greensboro, NC, USA

Chyer Kim Department of Family and Consumer Sciences, North Carolina A&TState University, Greensboro, NC 27411-1064, USA

Parakalan Krishnamachari North Carolina A&T State University, Greensboro,NC, USA

Lyubov A. Kurkalova North Carolina A&T State University, Greensboro, NC,USA

Marion Lamberth North Carolina Central University, Durham, NC, USA

Sikdar M.I. Latif North Carolina A&T State University, Greensboro, NorthCarolina 27411, USA

Wen-Yee Lee ESE Program; Chemistry Department, UTEP, El Paso, TX, USA

Tom LeFebvre NOAA Earth System Research Lab, Boulder, CO, USA

Diana Lenzner University of Pittsburgh, Graduate School of Public Health,Pittsburgh PA, USA

Xiaopeng Li North Carolina A&T State University, Greensboro, North Carolina27411, USA

xvi Contributors

Yebo Li The Ohio State University/Ohio Agricultural Development Center,Wooster, OH, USA

Jianzhong Lou Department of Chemical Engineering, North Carolina A&TState University, Greensboro, North Carolina 27411, USA

Stephanie Luster-Teasley North Carolina A&T State University, Greensboro,NC, USA

Rakesh Malhotra North Carolina Central University, Durham, NC, USA

Michael M. Marshall The University of North Carolina at Greensboro,Greensboro, NC, USA

Jeff Marston WCU, Cullowhee, NC, USA

Brent McCoy WCU, Cullowhee, NC, USA

William McDaniel Western Carolina University, Cullowhee, NC, USA

Gwendolyn McFadden-Wade North Carolina A&T State University, Greensboro,NC, USA

Faustina Meheux North Carolina Central University, Durham, NC, USA

Gary Mills University of Georgia SREL, Aiken, SC, USA

M.C. Nyman Department of Civil and Environmental Engineering, MRC 319,Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA

Ethelbert Odo Orient Home Care Services Inc., Grand Prairie TX, USA

Gbekeloluwa B. Oguntimein Department of Civil Engineering, Morgan StateUniversity, Baltimore, Maryland, 21251, USA

Ivie Okpere Department of Civil Engineering, Morgan State University,Baltimore, Maryland, 21251, USA

Somphavanh Phetsomphou North Carolina A&T State University, Greensboro,NC, USA

David Price North Carolina A&T State University, Greensboro, NC, USA

G.B. Reddy Department of Natural Resources and Environmental Design, NorthCarolina A&T State University, Greensboro, NC 27411, USA

D.J.R. Reeves University of North Carolina Wilmington, USA

Diana R. Robinson North Carolina A&T State University, Greensboro, NC, USA

Parke A. Rublee The University of North Carolina at Greensboro, Greensboro,NC, USA

Moussa M.E. Salem National Research Center, Dokki, Cairo, Egypt

Mary Sue Schultz NOAA Earth System Research Lab, Boulder, CO, USA

Contributors xvii

Silvia Secchi Iowa State University, Ames, IA, USA

Chung W. Seo North Carolina A&T State University, Greensboro, NC, USA

Abolghasem Shahbazi Department of Natural Resources and EnvironmentalDesign, North Carolina A&T State University, Greensboro, NC 27411-1064, USA

Myra M. Shird North Carolina Agricultural and Technical State University,Greensboro, NC, USA

Parikhit Sinha O’Brien & Gere, Blue Bell, Pennyslvania, USA

Garriet W. Smith University of SC, Aiken, SC, USA

Marie-Ange Smith University of SC, Aiken, SC, USA

Xianzhi Song Western Carolina University, Cullowhee, NC, USA

Sherry Southern U.S. DOE, Aiken, SC, USA

Sara E. Steudler Elon University, Elon, NC, USA

Katherine Suda North Carolina A&T State University, Greensboro, NC, USA

Nancy Sussman University of Pittsburgh, Graduate School of Public Health,Pittsburgh PA, USA

Kathleen E. Sykes U.S. EPA, Washington, DC, USA

Terrence Thomas North Carolina A&T State University, Greensboro, NC, USA

Brant W. Touchette Elon University, Elon, NC, USA

Leonard Uitenham North Carolina A&T ST.U., Greensboro, NC, USA

Leonard Uitenham North Carolina A&T State University, Greensboro, NC, USA

Godfrey A. Uzochukwu North Carolina A&T State University, Greensboro, NC,USA

Mary E. Uzochukwu North Carolina A&T State University, Greensboro,North Carolina

Renay Van Wyk Masters Environmental Health, University of Johannesburg,South Africa

Conrad Daniel Volz Department of Environmental and Occupational Health,Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA;Center for Environmental Oncology, Co-Director Exposure Assessment, Universityof Pittsburgh Cancer Institute, Pittsburgh, PA, USA; Scientific Director, Center forHealthy Environments and Communities, Pittsburgh, USA

Rashawn K. Washignton Chemical Engineering, North Carolina A&T StateUniversity, Greensboro, NC 27411, USA

Jean T. Wells Howard University, Washington, DC, USA

xviii Contributors

Donald Whitaker U.S. EPA National Exposure Research Laboratory, ResearchTriangle Park, NC, USA

John B. Williams Department of Biological & Physical Sciences, South CarolinaState University, Orangeburg, SC, USA

Ronald Williams U.S. EPA National Exposure Research Laboratory, RTP, NC,USA

Regina M. Williams North Carolina Agricultural and Technical State University,Greensboro, NC, USA

Vereda Johnson Williams Economics, Transportation and Logistics Department,North Carolina A&T State University, Greensboro, NC 27411, USA

Robert C. Wingfield Department of Chemistry, Fisk University, Nashville, TN37208, USA

Dereje Worku North Carolina A&T State University, Greensboro, NC, USA

Mulumebet Worku North Carolina A&T State University, Greensboro, NC, USA

Maxine Wright-Walters Department of Environmental and Occupational Health,Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA

Jizhong Yan North Carolina A&T State University, Greensboro, NC, USA

Thomas M. Yanoschak HDR, Raleigh, North Carolina, USA

Osei Yeboah North Carolina A&T State University, Greensboro, NC, USA

Jian Zhang University of Kansas, Greensboro, NC, USA

Part IBioprocessing

Synthesis of Poly(L(+) Lactic Acid)by Polycondensation Method in Solution

Jian Zhang, Parakalan Krishnamachari, Jianzhong Lou,and Abolghasem Shahbazi

Abstract The disposal problem due to non-degradable petroleum-based plasticshas raised the demand for biodegradable polymers. Poly(lactide) (PLA) is abiodegradable aliphatic polyester derived from 100% renewable resources, such ascorn and sugar beets. Moreover, it has unique physical properties that make it use-ful in diverse applications including paper coating, fibers, films, and packaging. Inthis work, the results of the synthesis of high molar weight poly(L(+) lactic acid)(PLA) which is able to thermally crystallize have been described. The synthesis ofpoly(L(+) lactic acid) was carried out in a solution of p-xylene. Tin(II) chloride wasused as catalysts in a quantity of 1.0 wt% calculated on the monomer. Polycondensa-tion was carried out over a period from ten to over 20 h. The resulting poly(L(+) lac-tic acids) were characterized by FT-IR, DSC and the GPC. The molecular weight ofPLLA reached as high as 26000. FTIR spectra of PLLA were analyzed to determinethe configuration of the PLLA. The main byproduct of condensation polymerizationis cyclo-polyester. The glass transition temperature of PLA after is 46.25◦C. PLAafter the recrystallization does not show glass transmission temperature because thecrystallinity is more than 40%.

Introduction

Poly(L-lactic acid) (PLLA) is synthesized from renewable resources and it hasreceived much interest in recent years. It is degraded by hydrolytic cleavage of theester bonds to produce lactic acid and its oligomers, which can be metabolized bymany microorganisms. Application of PLLA includes biomedical purposes suchas surgical sutures, fractured bone fixation, tissue engineering, and drug deliverysystems. Cargill Dow Co. began to produce PLLA on a commercial scale underthe trade name of Nature WorksTM. The price of PLLA has been reduced greatly

J. Lou (B)Department of Chemical Engineering, North Carolina A&T State University,Greensboro, North Carolina 27411, USA

G.A. Uzochukwu et al. (eds), Proceedings of the 2007 National Conferenceon Environmental Science and Technology, DOI 10.1007/978-0-387-88483-7 1,C© Springer Science+Business Media, LLC 2009

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owing to the technology developed by Cargill Dow Co. by combining agriculturalprocesses with biological and chemical technologies. (Richard and Bhanu 2002;Ray et al., 2000)

As far as we know, Cargill Dow Co. produces PLLA through ring openingpolymerization of L-lactide, which is formed by catalytic depolymerization oflow molecular weight PLLA prepolymer synthesized by direct polycondensationpolymerization of l-lactic acid (LA). Cargill Dow Co. employs this route mainlybecause direct condensation polymerization of LA in bulk state gives only low-to intermediate-molecular weight polymers due to the low equilibrium constant ofthe condensation polymerization reaction. A solvent with high boiling point, suchas xlyene, which is compatible with PLLA, is used for the removal of dissociatedwater by means of the so-called azeotropic distillation technique to shift the equilib-rium state to the polymer side. PLLA with high molecular weight can be producedthrough this solution polymerization route. This route requires large reactor volumeand facilities for evaporation and recovery of the solvent, which increases the pro-duction cost of PLLA. Recently, Mitsui Chemicals opened a new process based ondirect polycondensation of low-molecular weight PLLA in solid state without theuse of an organic solvent11 to produce high-molecular-weight PLLA.

Experimental Section

Materials. L-Lactic acid (LA) from Aldrich was a 85% aqueous solution ofthe monomer. The excess water was removed before use by distillation underreduced pressure at 100◦C. The following products were used without further treat-ment: Tin(II) chloride, Methanol, Chloroform and p-xylene all (HPLC grade) fromAldrich.

Polymerization. 80 g of the product of distillation L(+) lactic acid, 0.8 g Tin(II)chloride and 200 mL of xylene were added into a 600 mL Parr 4590 series stirredreactor and the reaction mixture was heated. The water was azeotropically dis-tilled off, and the reaction was continued at 160◦C for 24 h under reduced pressure(∼400 mm Hg). Then the Tin(II) chloride was filtered off, and the resulting polymerwas dissolved in chloroform, and then was precipitated twice in excess methanol.The product was dried in a vacuum oven at 60◦C until constant weight was attained.(Hiltunen et al., 1997)

Characterizations. The DSC measurements were carried out under a nitro-gen atmosphere with samples sealed into the standard DSC aluminum sample kitsusing DSC Q100 (TA instruments). The following thermal cycle was employed:First, the sample was heated up to a temperature 110◦C for 30 min; next, cooleddown to 20◦C; then, sample was heated up to 200◦C (1st scan) and then cooleddown to 10◦C; finally, heated to 200◦C again (2nd scan). The samples investigatedhad weights within the range of 5–10 mgs. Both heating and cooling rates were20◦C/min. By integrating the normalized area of the melting exotherm, determiningthe heat involved, and rating it to the reference 100% crystalline polymer (93.6 J/g),

Synthesis of Poly(L(+) Lactic Acid) by Polycondensation Method in Solution 5

the relative crystallinity of PLA was assessed. Infrared spectra were recorded witha Pike Miracle ATR, Ge crystal, single bounce on a Bruker Tensor 37 FTIR and4 wave number resolution scans for sample and background. GPC measurementswere performed on a Waters model 410 differential refractometer equipped withWaters Styragel HMW 6E THF column (7.8 × 300 mm) with effective molecularweight range 5000 to 1 × 107. Operating conditions were solvent THF; solute PLAand polystyrenes (standards of Shodex company); injected volume 20 μL; sampleconcentration of the order of 1 mg/ml. Flow rate of 1 mL/min. The sensitivity ofthe refractometer was set to 128 and a scale factor of 100 was adopted. (Aou et al.,2005)

Results and Discussion

Figure 1 presents the FTIR spectra of synthesized PLA. The 1758 cm-1 of FTIRspectra presents the C=O stretching region. And C-O-C stretching mode wasobserved at 1190 cm-1 as a IR band. 1459, 1392 and 2997 cm-1 regions are CH3and CH bending region and are further confirmed the existence of CH and CH3.1264 and 1099 cm-1 present the C-O stretching of cyclo-polyester. And this is themain byproduct of condensation polymerization. (Kister et al., 1998)

Figure 2 shows the DSC thermograms of the PLA. The results of thermal char-acterization are shown in Table 1. The first scan values for Tg, Tm and crystallinitydenote the properties of PLA just after the recrystallization at 110◦C for 30 min.The second scan values are results after heated to 200◦C cycle. The glass transition

3500

3510 2997

0.00

0.05

0.10

0.15

0.20

3000

Abs

orba

nce

Uni

ts

2500 2000Wavenumber cm–1

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1264

1392

17581190

1099

1000

Fig. 1 FTIR-spectrum of PLA

6 J. Zhang et al.

50

–10

–5

exot

herm

icH

eat F

low

(W

/g)

0

100

Tm=141.7°C; 8.186J/g

Tm=145.7°C; 59.83J/g

Tg=46.25°C

Temperature °C150 200

Fig. 2 DSC thermograms of PLA: 1st scan (after recrystallization at 110◦C, top dash line); 2ndscan (after first cycle, bottom solid line)

Table 1 Thermal characterization results

PLA Tg, ◦C Tm, ◦C ΔH, J/g Crystallinity, %

1st Scan – 145.7 59.83 63.92nd Scan 46.25 141.7 8.168 8.7

temperature of PLA after is 46.25◦C. PLA after the recrystallization does not showglass transmission temperature. because the crystallinity is more than 40%.

Polydisperse polymers in solution are fractionated according to size or hydrody-namic Volume during GPC, which is also known as size exclusion chromatography.Molecular weight is related to the hydrodynamic volume. In GPC a dilute poly-mer solution is injected into a solvent stream which then flows through a seriesof columns packed with porous gel beads. Smaller molecules pass through andaround the beads while larger molecules are excluded from all but the largest pores.Thus fractionation occurs with the largest molecules eluting first. The molecularweight of an eluting polymer molecule varies exponentially with eluting volume,the latter of which is proportional to time under constant flow rate conditions. Toobtain molecular weight data and convert the GPC chromatogram into a molecu-lar weight distribution, the relation between molecular weight and elution time isobtained from a series of polymer standards of known molecular weight. In thesestudy Polystyrene standards made by the Shodex company was used. Three differ-ent molecular weight standards was used, of the order of 104,105 and 106 respec-tively. Dependence between molecular size and molecular weight can be described

Synthesis of Poly(L(+) Lactic Acid) by Polycondensation Method in Solution 7

by Mark Houwink equation. The parameters K and Alpha as found in literature forthe both polymers in THF solvent is 0.011 ml/g, 0.725 and 0.00174 ml/g, 0.736 forPolystyrene and PLA respectively. This is used in the universal calibration method.We can calculate molecular mass of unknown polymer by using a calibration foranother (more common) polymer.

[η] = K Ma (1)

where η is the intrinsic viscosity and M is the molecular weight of the polymer.By linearizing the plot of Log (K∗Ma+1) versus the retention volume for differentstandards of polystyrene we can a get a slope and intercept of the fit. Which can beused back in fitting a straight line to already known values of K and a of PLA inTHF solvent. This helps us in finding the unknown molecular weight of PLA fromthe equation (Fig. 3) and GPC Chromatogram data of PLA (Fig. 4).

Log(K∗ Ma + 1) = (Retention time of PLA)∗Slope + Intercept (2)

7.5

5.5

6.0

6.5

7.0

7.5

8.0

8.5

9.0

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8.0 8.5 9.0Volume (ml)

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9.5 10.0Fig. 3 Polystyrenecalibration

8.30

Detectorresponse

Elution volume Vr (ml)11.56

Fig. 4 Chromatogramshowing the broad peak ofPLA

8 J. Zhang et al.

After substituting the appropriate values in equation (2) i.e. K = 0.00174 ml/g,a = 0.736 and the retention volume of 10.38, Molecular weight of PLA can be calcu-lated as: Log (0.00174 × M1.736) = –1.61302(10.38) + 21.652, M = 26.11 × 103.Therefore the Molecular weight of PLA is 26000.

Conclusion

PLLA was synthesized by the direct bulk condensation polymerization using Tin(II)chloride as a catalyst under reduced pressure (∼400 mm Hg). The molecular weightof PLLA reached as high as 26000. FTIR spectra of PLLA were analyzed to deter-mine the configuration of the PLLA. The main byproduct of condensation poly-merization is cyclo-polyester. The glass transition temperature of PLA after is46.25◦C. PLA after the recrystallization does not show glass transmission tempera-ture because the crystallinity is more than 40%.

Acknowledgments Funding for this project was provided by the USDA; Mrs. Nicole Whitemanof NatureWorks provided technical advice.

References

Aou, K., Kang, S., Hsu, S.L. 2005. Morphological study on thermal shrinkage and dimensionalstability associated with oriented poly(lactic acid). Macromolecues 38:7730–7735.

Hiltunen, K., Seppala, J.V., Harkonen, M. 1997. Effect of catalyst and polymerization conditionson the preparation of low molecular weight lactic acid polymers. Macromolecules 30:373–379.

Kister, G., Cassanas, G., Vert, M. 1998. Effects of morphology, conformation and configuration onthe IR and Raman spectra of various poly(lactic acid)s. Polymer 39:267–273

Ray, E.D., Patrick, R.G., David, E.H. 2000. Polylactic acid technology. Advanced Material12:1841.

Richard, A.G., Bhanu, K. 2002. Biodegradable polymers for the environment. Science 297:803.

The Feasibility of Using Cattails fromConstructed Wetlands to Produce Bioethanol

Katherine Suda, Abolghasem Shahbazi, and Yebo Li

Abstract This project investigates the feasibility of harvesting the cattails in theconstructed wetlands of the North Carolina A&T Farm to be converted into ethanol.Using the cattails to produce renewable energy will add value to the land as wellas reduce emissions of greenhouse gases by replacing petroleum products. Pretreat-ment of the dried cattails with dilute NaOH was followed by solid-liquid separationand enzymatic hydrolysis and fermentation of the solids. Two trials gave an averageconversion efficiency of 43.4% for the pretreated solids alone which, in conjunc-tion with the crop yield for the cattails, would give up to 4,012 L ethanol/ha, afavorable comparison with corn stover’s 1,665 L/ha at a 60% conversion rate. Giventhe high potential – 9,680 L/ha at 60% conversion efficiency for solid and liquidstreams – and the social and environmental benefits gained by adding value to thewaste management system and reducing carbon emissions otherwise made by gaso-line, it is recommended that further studies be made using cattails as a feedstock forbioethanol.

Introduction

Renewable transportation fuels are being developed to lower emissions of green-house gases and to enhance energy security. Biodiesel and starch-based ethanolpredominate, but the technology required for conversion of cellulose to ethanolis improving; some pilot plants are currently in operation, and the first full-scaleplants are due to come on line in 2007 and 2008. Cellulosic ethanol has a betterenvironmental profile than starch-based ethanol, with a 90% reduction in carbonemissions over gasoline as compared to a 29% reduction using starch-based ethanol(Wang, 2005), and it has the advantages of not requiring fertile agricultural land andof adding value to marginal farmland. Another benefit of cellulosic ethanol is the

K. Suda (B)North Carolina A & T State University, Greensboro, NC, USA

G.A. Uzochukwu et al. (eds), Proceedings of the 2007 National Conferenceon Environmental Science and Technology, DOI 10.1007/978-0-387-88483-7 2,C© Springer Science+Business Media, LLC 2009

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supply distribution afforded since it can be converted from a variety of cellulosicmaterials according to growing conditions and availability around the country.

One possible source of cellulosic feedstock is the cattails used for phytoreme-diation in constructed wetlands. Whereas harvesting plants from natural wetlandsis a sensitive issue because of possible environmental harm, harvesting the above-water portion of cattails once a year from a constructed wetland is a sustainablepractice which will not interfere with their role in cleaning the wastewater. Thereis no energy input required to grow them, as they receive their water and nutrientsfrom the wastewater. Using the cattails as a feedstock for bioethanol is one way toadd value to the land with little environmental impact.

This project examines the feasibility of using the cattails from constructed wet-lands to produce bioethanol. The focus is on pretreatment, followed by enzymatichydrolysis and fermentation of the solid fraction. Environmental impact, in termsof emissions reductions, is calculated, and economic factors are considered. Thepreliminary results are presented.

Methods

The basic steps to be followed in producing ethanol from cellulosic plant materialinclude harvesting, cleaning and shredding the feedstock, pretreatment, enzymatichydrolysis, fermentation, distillation and drying. This paper focuses on pretreatmentof the feedstock with sodium hydroxide followed by enzymatic hydrolysis and yeastfermentation.

Feedstock Characteristics. Cattails were cut and chopped with pruning shears,dried at 70◦C for 5 days, and ground in a Wiley mill to 2 mm mesh size. The energycontent for cattails was determined using a Parr bomb calorimeter. Dried sampleswere sent to Dairy One Forage Lab (Ithaca, NY) to be analyzed for cellulose, hemi-cellulose, and lignin content by ANKOM 200 Fiber Analyzer.

Pretreatment of the feedstock. Alkaline pretreatment was carried out in order torender the cellulose more accessible to the cellulase for enzymatic hydrolysis. About500 g of the dried, ground cattails were stirred into 5 L of a 1.0 N NaOH solution andleft at room temperature overnight. The mixture was then centrifuged for 20 min,after which, the liquid was poured off, the solids rinsed with water and re-suspendedin the water two times with centrifuging and decanting of the supernatant after eachrinse. Moisture content of the pretreated mix was determined by drying a sampleat 60◦C until weight was constant. Another sample was sent to Dairy One Labs forcellulose, hemicellulose and lignin analysis.

Culturing the yeast for fermentation. Saccharomyces cerevisiae (ATCC24858) and Yamadazyma stipitis (ATCC 58784) were used to ferment the sugars.Y. stipitis breaks xylose down producing ethanol, and S. cerevisiae produces ethanolfrom glucose. Aseptic technique was used to rehydrate the freeze-dried yeasts. Theywere incubated at 30◦C (S. cerevisiae) and 25◦C (Y. stipitis) and stepped up until 1.0L was obtained.

The Feasibility of Using Cattails from Constructed Wetlands to Produce Bioethanol 11

Enzymatic hydrolysis and fermentation. Enzymatic hydrolysis was carried outin two batches in a BioFLo 110 Fermentor/BioReactor (New Brunswick Scientific,Edison, NJ) at 50◦C, 4.8 pH and 200 rpm agitation. Pretreated cattails were mixedwith deionized water to a concentration of 50 g/L. Cellulase enzymes (Spezyme CP,Genencor International, Rochester, NY) were added at 82 GCU/g dry matter. ThepH was monitored and adjusted with buffer solutions of 5% NaOH and 5% HCl.Samples were taken throughout the process for later analysis by high pressure liq-uid chromatography (HPLC) using a 717 Plus Autosampler (Waters, Milford, MA).Hydrolysis proceeded for 24 h before yeasts were added. At 24 h, the temperaturewas reduced to 37◦C and the yeasts, S. cerevisiae and Y. stipitis, were added. Acondenser was attached to the fermentation vessels to allow cooling water to con-dense the evaporating ethanol back into the vessel. Fermentation proceeded at 37◦C,250 rpm agitation, and pH of 4.8, and the process was allowed to run for five days.

Results and Discussion

Feedstock Characteristics. Two years of data from the A&T Farm indicate that theaverage yield of cattails from the constructed wetlands is 16.1 mton/ha with a max-imum of 42.7 mton/ha (Dr. G.B. Reddy, personal communication, October 2006).The harvested plants had average moisture content (w.b.) of 78.6%. The energy con-tent at 5.4% moisture content (w.b.) was found to be 17.4 MJ/kg. Cellulose, hemi-cellulose and lignin content for the dry material were determined as 28.7%, 23.4%,and 10.1%, respectively. Because a large part of the energy in the process is used todry the feedstock, further studies should look at the possibility of using it withoutdrying.

Pretreatment. Supernatant from the pretreated material was analyzed by HPLCto determine the concentration of xylose, glucose and arabinose in the liquid por-tion of the hydrolyzate. The only sugar detected was xylose at 0.156% which wasdecided to be too little to pursue further. However, later it was questioned exactlyhow much 0.156% might have been as the supernatant had been diluted with therinse water. It may be possible to use suction filtration or a reverse osmosis mem-brane to separate the liquids and solids and get higher yields from the solid stream.Future plans are to track and ferment the liquid fraction separately.

After pretreatment, cellulose content had increased from 28.7% to 46.2% totaldry solids. Calculating the cellulose content based on the mass of pretreated drysolids shows that 28.7% of the cellulose was actually lost during pretreatment. Like-wise, hemicellulose and lignin were reduced in the solids, with lignin diminishingby 51.4%, and hemicellulose by 67.5%. Evaporation of the supernatant showed thatthere were suspended solids, presumably the lost cellulose. Hemicellulose is alka-line soluble, and most was expected to be dissolved by the NaOH, while lignin hasalkaline-soluble fractions (Reith et al., 2002; Walthers et al., 2001).

Enzymatic Hydrolysis and Fermentation. Enzymes began to convert thebiomass to sugars within 2 min of being added (Fig. 1). The initial glucose

12 K. Suda et al.

Enzymatic Hydrolysis and Fermentation in Reactor 1 (5% Concentration Dry Solids)

0.0

0.2

0.4

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0 20 40 60 80 100 120 140Time, h

Co

nce

ntr

atio

n, %

glucose xylose arabinose ethanol

24

Fig. 1 Enzymatic hydrolysis and fermentation in reactor 1

concentration measured 1.100% and 1.041% respectively, in reactor 1 and reactor2. Just before addition of the yeast, at 24 h, the glucose concentration had reached1.691% and 1.615%. Xylose showed an increase in concentration from 0.187%and 0.158% to 0.245% and 0.229% in reactors 1 and 2 respectively. The xylose intwo reactors and the glucose in one had actually started to decline in concentrationbefore the yeast was added. Possibly they were further degrading into compoundsthat were not being measured.

Arabinose concentration during enzymatic hydrolysis and fermentation wassteady at about 0.8%. The enzymes and yeast had no effect on it. The arabinosemust have been released during pretreatment. With addition of arabinose-fermentingyeasts, the ethanol yield could be increased.

Results of the HPLC showed ethanol yield in this study was 0.997% and 0.951%in the two reactors, which yields an average efficiency of 43.4%. This is equal to 94L ethanol/mton cattail. Badger (2002) reports a reasonable efficiency of 57% usingacid hydrolysis to give 227 L ethanol/mton dry corn stover. Using enzymatic hydrol-ysis was expected to give a higher yield. One reason for the low yield could be thatthe enzymes used in this study, Spezyme CP, are tailor-made for corn stover. Sup-plemental enzymes might improve yields. Better fermenting organisms have beendeveloped and a way of obtaining them for future studies is being studied. The twoyeasts used have different optimum temperatures. It is supposed that the ethanolproduced came from the glucose because of the higher than optimum temperaturefor Y. stipitis.

The Feasibility of Using Cattails from Constructed Wetlands to Produce Bioethanol 13

Tying the alcohol yield in with the yield of cattails from the wetlands gives anaverage of 1,521 L ethanol/ha cattails, and a maximum of 4,018 L ethanol/ha cat-tails. Based on current DOE estimates of 60% conversion efficiency (334 L/mton),and using the sustainable harvest amounts of corn stover for current tillage practices,we have an ethanol yield from corn stover of 804 L/ha, and for no-till farming, 1,665L/ha (Perlack et al., 2005). Assuming that further trials with cattails will approach60% efficiency, the yield of ethanol per acre of cattails could reach as much as 3,917L/ha.

Environmental Analysis

The preliminary study did not address the environmental impact of harvesting cat-tails. There will be no need for machinery, except for the once yearly sustainableharvest in late summer, so the detrimental environmental impact should be less thanfor feedstocks requiring fertilization and irrigation. In addition, the cattails are beingused for phytoremediation of wastewater, a benefit to the environment in itself.

The major benefit to the environment, if cattails were to be used as a feedstock forbioethanol, is the reduction in greenhouse gas emissions. Using a life cycle analysis,pure bioethanol emits 90% less carbon dioxide than an equivalent energy amountof gasoline (Wang, 2005). Pure ethanol has two thirds the energy of gasoline literper liter, and one liter of gasoline, over its life, emits 2.32 kg carbon dioxide. Todetermine the reductions in emissions achieved by using bioethanol, the followingformula can be used,

0.67 × 2.32 × 0.90 × EtOH = ES (1)

where EtOH is the amount of bioethanol in L/ha, and ES is the emissions (kg/ha)saved by using the bioethanol. By using this formula, it can be seen that using thebioethanol from corn stover with current tillage practices will save 1,115 kg CO2/ha.Cattails at average yield will save 2,128 kg CO2/ha and cattails at maximum pro-duction will save 5,621 kg CO2/ha. Once 60% conversion efficiency for cattails toethanol is achieved, the savings will rise to 5.2–13.4 mtons of carbon dioxide perhectare.

Economic Analysis

A complete economic analysis needs to be carried out including the cost of harvest-ing. Because of the wet nature of the cattail environment, special machinery mustbe designed to cut the plants without sinking into the soft soil. In the case wherethe wetlands are constructed with ethanol production in mind, the dimensions canbe designed to accommodate existing long-armed machinery such as those used tocut grass on highway banks. Sizing, storing, and processing costs are assumed to beapproximately equal to those of corn stover.

14 K. Suda et al.

Based on corn stover costs, a plant must have about 453–907 mtons/day to stayin operation (Fraser, 2006). Converting this weight of corn stover to a volume ofethanol gives a required 151,000–302,000 L/day. Assuming the plant operates 330days a year, the amount of land required per crop per year can be determined fromthe following formula,

(302, 800 × 330)/(EtOH) = A (2)

where EtOH is the amount of bioethanol in L/ha, and A is the area of landrequired in hectares. Using this formula gives a land requirement of about 60,000–124,000 ha/yr for corn stover and 25,000–66,000 ha/yr of cattails at the preliminary43% conversion rate.

Although cattails are abundant in North Carolina, particularly in the eastern partof the state, there are not very many constructed wetlands. However, some mid-size municipalities across the country have found them to be cost effective as partof their wastewater treatment (Gelt, 1997). In addition, cattails have been used toclean some industrial wastewater streams. An integrated system which uses mixedfeedstock including the cattails from constructed wetlands in the community shouldbe investigated as a promising scenario.

Conclusion

Although the initial trials using cattails to make bioethanol achieved only 43.4%conversion efficiency, it is believed that further trials will obtain better results byusing more advanced conversion organisms, and by combining the liquid and solidfractions. The low conversion rate is more than made up for by the high productivityof the wetlands, and by the reduction in emissions in the life cycle analysis of thefuel produced. With advances in technology, it is not unlikely that ethanol plantswill soon be able to use a variety of feedstocks. Cattails from constructed wetlandscould be a valuable part of an integrated system with their role as cleaning agentsand clean fuel feedstock.

Acknowledgments Many thanks are extended to Kevin Jenkins and Crystal Biddle for theirresearch assistance.

References

Badger, P. 2002. “Ethanol from Cellulose: a General Review.” In: J. Janick and A. Whipkey (Eds.),Trends in New Crops and New Uses. ASHS Press, Alexandria, VA.

Fraser, J. 2006. Best Kept Secret in the Ethanol Industry: BlueFire Ethanol (BFRE). Seeking Alpha:Stock Market Opinions and Analysis. Online at http://seekingalpha.com.

Gelt, J. 1997. “Constructed Wetlands: Using Human Ingenuity, Natural Processes to Treat Water,Build Habitat.” Arroyo , March 1997, 9(4).

Perlack, R., L. Wright, A. Turhollow, R. Graham, B. Stokes, and D. Erbach. 2005. “Biomass asFeedstock for a Bioenergy and Bioproducts Industry: the Technical Feasibility of a Billion-ton

The Feasibility of Using Cattails from Constructed Wetlands to Produce Bioethanol 15

Annual Supply.” A joint study sponsored by US DOE and USDA. Oak Ridge, TN: Oak RidgeNational Laboratory, 15 December 2005.

Reith, J., H. den Uil, H. van Veen, W. de Laat, J. Niessen, E. de Jong, H. Elbersen, R. Weusthuis,J. van Dijken, L. Raamsdonk. 2002. “Co-production of Bioethanol, Electricity and Heat fromBiomass Residues.” In: Twelfth European Conference and Technology Exhibition on Biomassfor Energy, Industry and Climate Protection, Amsterdam, The Netherlands.

Walthers, T., P. Hensirisak, and F. Agblevor. 2001. “Model Compound Studies: Influence of Aer-ation and Hemicellulosic Sugars on Xylitol Production by Candida Tropicalis.” Applied Bio-chemistry and Biotechnology 91–93:423–435.

Wang, M. 2005. “The Debate on Energy and Greenhouse Gas Emissions Impacts of Fuel Ethanol.”Argonne National Laboratory. Energy Systems Division Seminar. Chicago, IL, 3 August 2005.