• BS, Geological Engineering with Honors, New Mexico State University, 1997
• MS, Environmental Engineering, University of Illinois at Urbana-Champaign, 1999
• Ph D, Environmental Engineering, University of Illinois at Urbana-Champaign, 2003

Journal Articles

C. R. Fernandez Pulido, Pandara Valappil Femeena and R. A. Brennan, 2024, "Nutrient cycling with duckweed for the fertilization of root, fruit, leaf, and grain crops: impacts to plant-soil-leachate systems", Agriculture, 14, (2)

P. V. Femeena, B. Roman and R. A. Brennan, 2023, "Maximizing duckweed biomass production for food security at low light intensities: experimental results and an enhanced predictive model.", Environmental Challenges, 11, (100709)

P. V. Femeena, C. Costello and R. A. Brennan, 2023, "Spatial optimization of nutrient recovery from dairy farms to support economically viable load reductions in the Chesapeake Bay Watershed.", Agricultural Systems, 207, (103640)

Rachel A Brennan, F Pandara Valappil and G R House, 2022, "Creating a circular nitrogen bioeconomy in agricultural systems through nutrient recovery and upcycling by microalgae and duckweed: past efforts and future trends", Transactions of the American Society of Agricultural and Biological Engineers (ASABE) Special Collection: Circular Food and Agricultural Systems., 65, (2)

B. Roman and R. A. Brennan, 2021, "Duckweed protein supports the growth and organ development of mice: a feeding study comparison to conventional casein protein", Journal of Food Science, 86, (3), pp. 1097-1104

B. Roman and R. A. Brennan, 2021, "Life cycle assessment of an Eco-Machine indicates beneficial environmental impacts for upcycling wastewater nutrients into protein-rich duckweed", Journal of Environmental Management, 288

Rachel A Brennan, Fernandez Pulido, C R Zhang, J J Caballero and M A Bruns, 2021, "Lemna minor (duckweed) enhances crop yield and nutrient retention in agricultural soils", Ecological Engineering, 168, pp. 106273

Rachel A Brennan, M A Arenas and F Pandara Valappil, 2021, "The Water-Energy-Food Nexus Discovery Map: linking geographic information systems, academic collaboration, and large-scale data visualization", Sustainability, 13, pp. 5220

B Roman and Rachel A Brennan, 2021, "Life cycle assessment of an Eco-MachineTM indicates beneficial environmental impacts for upcycling wastewater nutrients into protein-rich duckweed", Journal of Environmental Management, 288, pp. 112361

O Calicioglu, C Mutel, D L Sills, T. L Richard and Rachel A Brennan, 2021, "Techno-economic analysis and life cycle assessment of an integrated wastewater-derived duckweed pond and biorefinery", ACS Sustainable Chemistry & Engineering, 9, pp. 9395 - 9408

Y Lin, J A Grembi, S S Goots, A Sebastian, I Albert and Rachel A Brennan, 2021, "Development and adaptability of microbial communities in pilot-scale field reactors treating acid mine drainage amended with crab shell", Journal of Hazardous Materials, 420, (126665)

O Calicioglu, F Pandara Valappil, M Y Sengul and Rachel A Brennan, 2021, "Duckweed growth model for large-scale applications: optimizing harvesting regime and intrinsic growth rate via machine learning to maximize biomass yields", Journal of Cleaner Production, 324, (15)

R J Harvey, D D Davis, B Savani, Rachel A Brennan and J A Pecchia, 2021, "Nitrate removal in greenhouse water using mushroom compost within artificially constructed wetlands", Journal of Plant Science and Research, 8, (2)

C. R. Fernandez Pulido, W. Zhang, J. J. Caballero, M. A. Bruns and R. A. Brennan, 2021, "Recovery of waste nutrients by duckweed for reuse in sustainable agriculture: second-year results of a field pilot study with sorghum", Ecological Engineering, 168, (106273)

L. Yishan and Rachel A Brennan, 2020, "Crab shell amendments enhance the abundance and diversity of key microbial groups in sulfate-reducing columns treating acid mine drainage", Applied Microbiology and Biotechnology, 104, (19), pp. 8505-8516

B. Roman and R. A. Brennan, 2019, "A beneficial by-product of ecological wastewater treatment: an evaluation of wastewater-grown duckweed as a protein supplement for sustainable agriculture.", Ecological Engineering, 1, (100004)

A. N. Kreider, C. R. Fernandez Pulido, M. A. Bruns and R. A. Brennan, 2019, "Duckweed as an agricultural amendment: nitrogen mineralization, leaching, and sorghum uptake", Journal of Environmental Quality, 48, (2)

O. Calicioglu, T. L. Richard and R. A. Brennan, 2019, "Anaerobic bioprocessing of wastewater-derived duckweed maximizing product yields in a biorefinery value cascade", Bioresource Technology, 289

M. J. Shreve, A. Brockman, M. Hartleb, S. Prebihalo, F. L. Dorman and R. A. Brennan, 2016, "The white-rot fungus Trametes versicolor reduces the estrogenic activity of a mixture of emerging contaminants in wastewater treatment plant effluent", International Biodeterioration & Biodegradation, 109, pp. 132-140

J. A. Grembi, B. A. Sick and R. A. Brennan, 2016, "Remediation of high-strength mine impacted water with mixed organic substrates containing crab shell and spent mushroom compost", Journal of Environmental Engineering, 142, (2), pp. 04015075

D. J. Kelsey, C. Nieto-Delgado, F. S. Cannon and Rachel A Brennan, 2015, "Incorporation of organic fungicides in bindered anthracite bricks for improved storage and performance in iron foundries", Journal of Applied Microbiology, 119, pp. 65-75

J. A. *McElhoe and Rachel A Brennan, 2012, "Effect of chitin purity and proppant loading on the bioremediation of chloroethenes", Journal of Environmental Engineering, 138, (8), pp. 862-872

J. A. Grembi, B. A. Sick, S. S. Goots, S. Lin and Rachel A Brennan, 2011, "Remediation of high-strength mine impacted water with crab shell substrate mixtures: laboratory column and field pilot tests", National Meeting of the American Society of Mining and Reclamation

M. A. Robinson-Lora and Rachel A Brennan, 2011, "Anaerobic precipitation of manganese and co-existing metals in mine impacted water treated with crab shell-associated minerals", Applied Geochemistry, 26, pp. 853-862

C. E. Newcombe and Rachel A Brennan, 2010, "Improved passive treatment of acid mine drainage in mushroom compost amended with crab-shell chitin", Journal of Environmental Engineering, 136, (6), pp. 616-626

M. A. Robinson-Lora and Rachel A Brennan, 2010, "Biosorption of manganese onto chitin and associated proteins during the treatment of mine impacted water", Chemical Engineering Journal, 162, pp. 565-572

H. Cai, A. G. Eramo, P. J. Evans, R. Fricke and Rachel A Brennan, 2010, "In situ bioremediation of perchlorate in vadose zone soil using gaseous electron donors: microcosm treatability study", Water Environment Research, 82, (5), pp. 409-417

M. A. Robinson-Lora and Rachel A Brennan, 2010, "Chitin complex for the remediation of mine impacted water: geochemistry of metal removal and comparison with other common substrates", Applied Geochemistry, 25, (3), pp. 336-344

M. A. Robinson-Lora and Rachel A Brennan, 2009, "The use of crab-shell chitin for biological denitrification: batch and column tests", Bioresource Technology, 100, (2), pp. 534-541

M. A. Robinson-Lora and Rachel A Brennan, 2009, "Efficient metal removal and neutralization of acid mine drainage by crab-shell-chitin under batch and continuous-flow conditions", Bioresource Technology, 100, (21), pp. 5063-5071

L. N. Daubert and Rachel A Brennan, 2007, "Passive remediation of acid mine drainage using crab shell chitin", Environmental Engineering Science, 24, (10), pp. 1475-1480

F. Rezaei, T. L. Richard, Rachel A Brennan and B. E. Logan, 2007, "Substrate-enhanced microbial fuel cells for improved remote power generation from sediment-based systems", Environmental Science & Technology, 41, (11), pp. 4053-4058

Rachel A Brennan, R. A. Sanford and C. J. Werth, 2006, "Chitin and corncobs as electron donor sources for the reductive dechlorination of tetrachloroethene", Water Research, 40, (11), pp. 2125-2134

Rachel A Brennan, R. A. Sanford and C. J. Werth, 2006, "Biodegradation of tetrachloroethene by chitin fermentation products in a continuous flow column system", Journal of Environmental Engineering, 132, (6), pp. 664-673

Rachel A Brennan and R. A. Sanford, 2002, "A continuous steady-state method for delivering tetrachloroethene (PCE) to chlororespiring bacteria using Tenax", Applied and Environmental Microbiology, 68, (3), pp. 1464-1467

E. Egemen, J. Corpening, J. Padilla, Rachel A Brennan and N. Nirmalakhandan, 1999, "Evaluation ozonation and cryptic growth for biosolids management in wastewater treatment", Water Science & Technology, 39, (10), pp. 155-158

F. G. Edwards, E. Egemen, Rachel A Brennan and N. Nirmalakhandan, 1999, "Ranking of toxics release inventory chemicals using a level III fugacity model and toxicity", Water Science & Technology, 39, (10), pp. 83-90

Rachel A Brennan, N. Nirmalakhandan and R. E. Speece, 1998, "Comparison of predictive methods for Henrys law coefficients of organic chemicals", Water Research, 32, (6), pp. 1901-1911

Rachel A Brennan, 1998, "Daniel W. Mead Student Paper Contest Winners", Journal of Professional Issues in Engineering Education and Practice, 124, (2), pp. 32-35

N. Nirmalakhandan, Rachel A Brennan and C. Trevizo, 1998, "Groundwater treatment by cascade air-stripping process", New Mexico Journal of Science, 38, pp. 348-360

N. Nirmalakhandan, S. Xu, C. Trevizo and Rachel A Brennan, 1997, "Additivity in microbial toxicity of non-uniform mixtures of organic chemicals", Exotoxicology & Environmental Safety, 37, (1), pp. 97-102

N. Nirmalakhandan, Rachel A Brennan and R. E. Speece, 1997, "Predicting Henrys constant and the effect of temperature on Henrys constant", Water Research, 31, (6), pp. 1471-1481

O. Calicioglu, M. J. Shreve, T. L. Richard and R. A. Brennan, , "Effect of pH and temperature on microbial community structure and carboxylic acid yield during the acidogenic digestion of duckweed", Biotechnology for Biofuels, 11, pp. 19

O. Calicioglu and R. A. Brennan, , "Sequential ethanol fermentation and anaerobic digestion increases bioenergy yields from duckweed.", Bioresource Technology, 257, pp. 344-348

M. J. Shreve and R. A. Brennan, , "Trace organic contaminant removal in six full-scale integrated fixed-film activated sludge (IFAS) systems treating municipal wastewater", Water Research, 151, pp. 318-331

Magazines/Trade Publications

C. Chan and Rachel A Brennan, 2011, "Hydroponic rafts may be a solution to Chinese water pollution"

C. Chan and Rachel A Brennan, 2010, "Clean water act", Engineering Penn State, 26, (1), pp. 12-13

Rachel A Brennan, 2010, "Getting crabby about high-strength mine drainage? The combination of chitin, protein, and calcium carbonate in crab shells may offer a passive treatment solution", Reclamation Matters, Autumn Issue

A. Eramo and Rachel A Brennan, 2009, "A new use for used mushroom compost: bioremediation of diesel-contaminated soil", Mushroom News

E. Spanier and Rachel A Brennan, 2009, "Crustacean cleanup: crab shell chitin shows promise in remediating acid mine drainage"

Manuscripts

Ayse Ozgul Calicioglu and R. A. Brennan, , "Duckweed growth model for large-scale applications: optimizing harvesting regime and intrinsic growth rate via machine learning to maximize biomass yields.", Journal of Cleaner Production, 324, (15), pp. 19

• November 2020 - October 2025, "ECO-CBET: Transforming the Nitrogen Bioeconomy," (Sponsor: National Science Foundation).

• May 2020 - September 2025, "Food Resilience in the Face of Catastrophic Global Events," (Sponsor: Open Philanthropy Project [MP]).

• June 2021 - May 2025, "IGE: Stakeholder-Driven Sustainable Development Experiences for Enhancing STEM Graduate Education," (Sponsor: National Science Foundation).

• July 2019 - June 2024, "A Systems Approach for Meeting Local and Global Food-Energy-Water Nexus Challenges," (Sponsor: Strategic Initiative).

• September 2021 - August 2024, "IRES Track I: Manifestations of climate change in extreme events," (Sponsor: National Science Foundation).

• July 2022 - June 2024, "A New Sustainable Lab Ambassador Program within the College of Engineering.," (Sponsor: The Leonhard Center for Enhancement of Engineering Education).

• March 2022 - June 2023, "A one-stop online platform for water-energy-food nexus research: Integrating systems modeling and deep learning-based literature mining.," (Sponsor: IEE Sustainability Seed Grant Program).

• January 2020 - May 2022, "Drawdown as a Unifying Theme in First Year Seminars to Promote Engagement and Retention within the College of Engineering," (Sponsor: The Leonhard Center for Enhancement of Engineering Education).

• January 2020 - August 2022, "Integrating Law, Policy, and Engineering: Digital Open Badges for Sustainability," (Sponsor: The Leonhard Center for Enhancement of Engineering Education).

• January 2021 - December 2022, "Piloting a Water-Energy-Food Nexus Model for Improving Smallholder Livelihoods and Environmental Sustainability in Magdalena, Colombia," (Sponsor: Penn State Global Programs, University of Bogota Jorge Tadeo Lozano (UTadeo), and the Colombian Institute of Educational Credit and Technical Studies Abroad (ICETEX)).

• Fulbright Specialist, U.S. Department of State, 2019 - 2023

• Executive Leadership in Academic Technology, Engineering, & Science (ELATES) Fellow, April 2020 - May 2022

• Distinguished Honors Faculty, Schreyer Honors College, 2019 - 2021

• Premiere Teaching Award, Penn State Engineering Alumni Society, 2014

• Harry West Teaching Award for the Advancement of Civil Engineering Education, 2014

• Faculty Early Career Development (CAREER) Award, National Science Foundation, 2007 - 2013

• Kavli Fellow, National Academy of Sciences, 2012

• McKee Groundwater Protection, Restoration, or Sustainable Use Award, Water Environment Federation, 2011

• Outstanding Teaching Award, Penn State Engineering Alumni Society, 2011

• Oustanding Professor Award, Alpha Chi Sigma Professional Chemistry Fraternity, 2007

Service to Penn State:

• Committee Work, Chairperson, College of Engineering Promotion and Tenure Committee, September 2023 - 2024

• Academic Leadership and Support Work, Other, Interim Associate Head, July 2023

• Academic Leadership and Support Work, Chairperson, Interim Associate Head, Faculty Search Committee, November 2023

• Academic Leadership and Support Work, Chairperson, Interim Associate Head, Strategic Action Committee, August 2023

• Committee Work, Member, College of Engineering Promotion and Tenure Committee, May 2022 - 2023

• Academic Leadership and Support Work, Coordinator, College of Engineering Strategic Planning Implementation, September 2021 - 2023

• Committee Work, Member, Affiliate Faculty, Strategic Planning for the Department of Civil & Environmental Engineering, July 2021 - 2022

• Committee Work, Chairperson, Affiliate Faculty, Diversity, Equity, & Inclusion Committee, Department of Civil and Environmental Engineering, November 2021 - August 2022

• Assistance to Student Organizations, Advisor, Engineers for a Sustainable World, Penn State Chapter, December 2020

• Academic Leadership and Support Work, Director, Drawdown Scholars Research Experiences for Undergraduates Program, 2020 - 2023

• Academic Leadership and Support Work, Director, Water-Energy-Food Nexus Strategic Initiative, 2019 - 2025

• Committee Work, Chairperson, Teaching Excellence Committee, January 2018 - June 2020

• Committee Work, Chairperson, Sustainability Council, College of Engineering, 2018 - 2022

• Committee Work, Chairperson, Sustainability Council, August 2018 - July 2022

• Committee Work, Other, Area Coordinator for Environmental Engineering, 2018 - 2019

• Committee Work, Chairperson, Capstone Coordinator for Civil Engineering, August 2017 - May 2018

• Academic Leadership and Support Work, Director, Advanced Ecological Engineering Systems Laboratory (Eco-Machine), 2008

Service to External Organizations:

• Service to Citizen and/or Client Groups, Instructor, Facilities Water Conservation and Mngmt, Facilities Engineering Institute, 2020 - 2023

• Service to Governmental Agencies, Other, Vice-Chair, State College Borough Water Authority Advisory Board, January 2018