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Dr Shuiwang Duan

Asst Research Scientist

Assistant Research Scientist

Environmental Science & Technology 0223 H.J. Patterson Hall 1126 Campus Dr College Park, MD 20742-2315


  • Water Quality
  • Water and Nutrient Management
  • Stream and River Restorations
  • Stable Light Isotopes
  • ARC GIS application in watershed water quality


  • M.S. in Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Science, 1997.
  • B.S. in Geology, Chengdu University of Technology, 1994.

Pollutions of nutrients, organic contaminants and heavy metals in agricultural/urban stormwater, streams, rivers and coastal waters.  Impacts of land-use and land-cover and climate changes on sources and transport of pollutions from watersheds to coastal. Managing and restoring freshwater ecosystems at agricultural and urban area. Application of geographic information system (GIS) and modeling in watershed pollution management.


My current research focuses on Nutrient management in the Chesapeake Bay Watershed

• Monitoring edge-of-field stormwater runoff from Maryland agricultural landscapes
Effects of agricultural practices on quantity and quality of fluvial organic matter
• Application of nitrate dual isotopes in tracking sources of nitrogen

Past Projects: 

  • Sources, Transport and management Organic Carbon, Nitrogen and Phosphorus in Urban Stormwater Runoff.
  • Hotspots of Emerging Contaminants (e.g., Endocrine disrupting chemicals), Nutriensts and Trace Elements in the Potomac Watersheds and Management Practice.
  • Organic Matter and Nutrients in Large Rivers and Coastal Waters.
  • Effect of Warming and Road Salt Application on Release of Organic Matter, Nutrients and Sulfate from Sediment in Urban Area


Zhang, Z.Y., J.L. Huang, S.W. Duan, Y.L. Huang, J.T. Cai, J. Bian. Use of an interpretable machine learning method to identify the factors influencing the nonlinear linkage between land use pattern with river water quality: A case study in Chesapeake Bay watershed. In prep.

Duan, S.W., L.R. Iwanowicz, K. Noguera-Oviedo, P. He, S.S. Kaushal, E.J. Rosenfeldt, D.S. Aga, S. Murthy. 2021. Hot Spot analysis of endocrine-disrupting compounds and estrogenic activity in the Potomac Watershed. In prep.

Duan, S.W., S.S. Kaushal, P. He, E. Rosenfeldt, D.S. Aga, S. Murthy. Co-management of endocrine-disrupting compounds and nutrients with Best Management Practices and wastewater treatment plants in the Potomac River Watershed. In prep.

Duan, S.W., M. Evans, S.S. Kaushal, J.L. Huang, E. Rosenfeldt, S. Murthy. Catchment lithology and land use controls on dissolved inorganic carbon in the Potomac River, USA. In Prep.

Kaushal, S.S., J.E. Reimer, P.M. Mayer, R.R. Shatkay, C. Maas, W.D. Nguyen, W.L. Boger, A.M. Yaculak, T.R. Doody, M. Pennino, N.W. Bailey, J.G. Galella, A. Weingrad, D.C. Collison, K.L. Wood, S. Haq, T.N. Johnson, S. Duan, K.T. Belt. Freshwater salinization syndrome alters retention and release of multiple contaminants along the green infrastructure (GI) tract. Submitted to Freshwater Science.

Kaushal, S.S., G.E. Likens, P.M. Mayer, M.L. Pace, J.E. Reimer, C.M. Maas, J.G. Galella, R.M. Utz, S.W. Duan et al. 2021. Freshwater Salinization Syndrome: from Emerging Global Problem to Managing Risks. Biogeochemistry, 154, 255–292. DOI: 10.1007/s10533-021-00784-w.

Duan, S.W., K. Banger, and G.S. Toor. 2021. Evidence that Phosphate Mining and Agriculture Influence Nutrient Concentrations, Forms and Ratios in a Watershed in Central Florida. Water, 12(8): 1046.

Duan, S.W., S.S. Kaushal, J.L. Huang. E. Rosenfeldt, S. Murthy. 2021. Changes in sources and transformation of dissolved nitrogen along the Potomac River (USA) across a land use gradient. Applied Geochemistry, 131, 105006.

Guardian, M.G.E., P. He, A. Bermudez, S.W. Duan, S.S. Kaushal, E. Rosenfeldt, D.S. Aga. 2021. Optimized Suspect Screening Approach for a Comprehensive Assessment of the Impact of Best Management Practices in Reducing Micropollutants Transport in the Potomac River Watershed. Water Research, X (11), 100088.

Duan, S.W., L.R. Iwanowicz, K. Noguera-Oviedo, S.S. Kaushal, E.J. Rosenfeldt, D.S. Aga, S. Murthy. 2021. Evidence that Watershed Nutrient Management Practices Effectively Reduce Estrogens Pollution in Environmental Waters. Science of The Total Environment, 758, 143904.

Kalev, S., S.W. Duan, G.S. Toor. 2021. Enriched dissolved organic carbon export from a residential stormwater pond. Science of the Total Environment. doi: 10.1016/j.scitotenv.2020.141773.

Huang, Y.L., J.L. Huang , A. Ervinia, S.W. Duan. 2020. Tracking riverine nitrate sources under changing land use pattern and hydrologic regime. Mar Pollut Bull152:110884. doi: 10.1016/j.marpolbul.2020.110884. Epub 2020 Jan 25.

Huang, Y.L., Huang, J.L., A. Ervinia, S.W. Duan, S. Kaushal. 2021. Land use and climate variability amplifies watershed nitrogen exports in coastal China.  Ocean and Coastal Management, 104428,

Duan, S.W., P.M. Mayer, S.S. Kaushal, B.M. Wessel, T. Johnson. 2019. Regenerative stormwater conveyance (RSC) for reducing nutrients in urban stormwater runoff depends upon carbon quantity and quality. Science of The Total Environment 652: 134-146.

Haq, S., S.S. Kaushal, S.W. Duan. 2018. Episodic salinization mobilizes base cations, carbon, and nutrients from sediments to stream water across urban metropolitan regions. Biogeochemistry 141: 463–486.

Kaushal, S.S., S. Duan, T.R. Doody, S. Haq, R.M. Smith, T.A. Newcomer Johnson, K. Delaney Newcomb, J. Gormana, N. Bowman, P.M. Mayer, K.L. Wood, K.T. Belt, W.P. Stack. 2017. Human-accelerated weathering increases salinization, major ions, and alkalinization in fresh water across land use. Applied Geochemistry, 83: 121-135.

Duan, S.W., Y.X. He, S.S. Kaushal, T.S. Bianchi, N.D. Ward, L. Guo. 2017. Impact of wetland decline on decreasing dissolved organic carbon concentrations along the Mississippi River continuum.  Frontiers in Marine Sciences, 3:280. doi: 10.3389/fmars.2016.00280.

Duan, S.W., T.A. Newcomer-Johnson, P. Mayer, and S.S. Kaushal. 2016. Phosphorus retention in stormwater control structures across streamflow in urban and suburban watersheds. Water, 8, 390; doi:10.3390/w8090390.

Lu, T., N. Chen, S. Duan, Z. Chen, B. Huang. 2016. Hydrological controls on cascade reservoirs regulating phosphorus retention and downriver fluxes. Environ Sci Pollut Res Int. 23(23): 24166-24177.

Zhou, X., N. Chen, Z. Yan, S. Duan. 2016. Warming increases nutrient mobilization and gaseous nitrogen removal from sediments across cascade reservoirs. Environ Pollut., 219:490-500. doi: 10.1016/j.envpol.2016.05.060.

Mo, Q., N. Chen, X. Zhou, J. Chen, S. Duan. 2016. Ammonium and phosphate enrichment across the dry-wet transition and their ecological relevance in a subtropical reservoir, China. Environ Sci Process Impacts., 13;18(7):882-94. doi: 10.1039/c6em00225k.

Yang, Q., X. Zhang, X. Xu, G.R. Asrar, R.A. Smith, J.S. Shih, S. Duan. 2016. Spatial patterns and environmental controls of particulate organic carbon in surface waters in the conterminous United States. Sci Total Environ., 554-555: 266-275. doi: 10.1016/j.scitotenv.2016.02.164.

Duan, S.W., and S.S. Kaushal. 2015. Salinization alters fluxes of bioreactive elements from stream sediments and soils across land use. Biogeosciences, 12, 7331–7347, doi:10.5194/bg-12-7331-2015.

Zheng, G.M., P. DiGiacomo, S.S. Kaushal, M. Yuen-Murphy, and S.W. Duan. 2015. Evolution of sediment plumes in the Chesapeake Bay and implications of climate variability. Environmental Science & Technology, 49(11):6494-503. doi: 10.1021/es506361p.

Duan, S.W., N.H. Chen, S. Kaushal, P. Chigbu, A. Ishaque, E. May. 2015. Dynamics of dissolved organic carbon and nitrogen in the Maryland Coastal Bays. Estuarine, Coastal and Shelf Science, 164 (5), 451–462.

Brinkmeyer R, Amon RM, Schwarz JR, Saxton T, Roberts D, Harrison S, Ellis N, Fox J, DiGuardi K, Hochman M, Duan S, Stein R, Elliott C.  2015. Distribution and persistence of Escherichia coli and Enterococci in stream bed and bank sediments from two urban streams in Houston, TX.  Science of the Total Environment 502: 650-658. doi: 10.1016/j.scitotenv.2014.09.071.

Duan, S.W., R.T. Powell, and T. S. Bianchi. 2014.  High frequency measurement of nitrate concentration in the Lower Mississippi River, USA. Journal of Hydrology 519: 376–386 doi:10.1016/j.jhydrol.2014.07.030

Duan, S. W., K. Delaney-Newcomb, S. S. Kaushal, S. E. G. Findlay, K. T. Belt. 2014. Potential effects of leaf litter on water quality in urban watersheds. Biogeochemistry 121: 61-80 doi:10.1007/s10533-014-0016-9

Duan, S.W., R. M.W. Amon, R. L. Brinkmeyer. 2014. Tracing sources of organic matter in adjacent urban streams having different degrees of channel modification. Science of the Total Environment 485-486: 252-262 doi: 10.1016/j.scitotenv.2014.03.066.

Kaushal, S.S., K. Delaney-Newcomb, S.E.G. Findlay, T.A. Newcomer, S. Duan, M.J. Pennino, G.M. Sivirichi, A.M. Sides-Raley, M.R. Walbridge, K.T. Belt. 2014. Longitudinal patterns in carbon and nitrogen fluxes and stream metabolism along an urban watershed continuum. Biogeochemistry 121: 23–44 doi: 10.1007/s10533-014-9979-9

Kaushal, S. S., P. M. Mayer, P. G. Vidon, R. M. Smith, M. J. Pennino, T. A. Newcomer, S.W. Duan, C. Welty, and K. T. Belt. 2014. Land use and climate variability amplify carbon, nutrient, and contaminant pulses: a review with management implications. Journal of the American Water Resources Association (JAWRA) 50: 585-614 doi: 10.1111/jawr.12204

Duan, S. Allison, M.A., Bianchi, T.S., McKee, B.A., Shiller, A. M., Guo, L. and Rosenheim, B.  2013. Sediment, Organic carbon, Nutrients, and Trace Elements:  Sources, Transport, and Biogeochemical Cycles in the Lowermost Mississippi River, In “Biogeochemical Dynamics at Major River-Coastal Interfaces: Linkages with Global Climate Change” Edited by T.S. Bianchi, M.A. Allison and W.J. Cai, Chapter-16, pp. 397-420, Cambridge University Press (ISBN 9781107022577).

Duan, S.W., and S. S. Kaushal. 2013. Warming increases carbon and nutrient fluxes from sediments in streams across land use. Biogeosciences 10: 1193-1207 doi:10.5194/bg-10-1193-2013

Duan, S.W., S. S. Kaushal, P. M. Groffman, L. E. Band, and K. T. Belt. 2012. Phosphorus export across an urban to rural gradient in the Chesapeake Bay watershed. Journal of Geophysical Research – Biosciences 117, G01025, doi: 10.1029/2011JG00178.

Amon, R.M.W., A.J. Rinehart, S. Duan, P. Louchouarn, A. Prokushkin, G. Guggenberger, D. Bauch, C. Stedmon, P.A. Raymond, R.M. Holmes, J.W. McClelland, B.J. Peterson, S.A. Walker, A.V. Zhulidov. 2014. Dissolved organic matter sources in large Arctic rivers.  Geochimica et Cosmochimica Acta 94: 217–237 doi:10.1016/j.gca.2012.07.015

Shiller, A.M., Shim, M.J., Guo, L., Bianchi, T.S., Smith, R. Duan, S.W. 2012. Hurricane Katrina impact on water quality in the east Pearl River, Mississippi. Journal of Hydrology, 414/415: 388-392 doi:10.1016/j.jhydrol.2011.11.010.

Duan S.W., R.W.M. Amon, T.S. Bianchi and P.H., Santschi. 2011.  Temperature control soluble reactive phosphorus in the lower Mississippi River? Estuaries and Coasts 34(1): 78-89 doi 10.1007/s12237-010-9284-3.

Xu, C., Santschi, P.H., Hung,C.-C., Zhang,S., Schwehr,K,A., Roberts,K.A., Guo, L.D., Gong, G.-C., Quigg, A., Long, R., Pinckney, J., Duan, S.W., Amon, R., and Wei, C.L.2011. Controls of Th-234 removal from the oligotrophic ocean by polyuronic acids and microbial activity. Marine Chemistry 123: 111-126, doi:10.1016/j.marchem.2010.10.005.

Duan S.W., R.W.M. Amon, T.S. Bianchi, and P.H., Santschi. 2010. Effects of Tributary Inputs on Nutrient Export from the Mississippi and Atchafalaya River. Marine and Freshwater Research 61(9):1029–1038  doi:10.1071/MF09235

Louchouarn P., R. Amon, and S. Duan. 2010. Analysis of low-level lignin-derived phenols in environmental samples by gas chromatography/tandem mass spectrometry. Marine Chemistry 118 (1-2): 85-97 doi:10.1016/j.marchem.2009.11.003.

Walker, S.A., Amon, R.M.W., Stedmon, C., Duan, S.W., and Louchouarn, P. 2009. The use of PARAFAC modeling to trace terrestrial dissolved organic matter and finger-print water masses in Canadian Arctic surface waters. Journal of Geophysical Research- Biosciences 114, G00F06, doi:10.1029/2009JG000990.

Duan, S.W., L. Tao, L.J. Wang, X.M. Zhang, and X.B. Chen. 2008.  Seasonal Changes in Nitrogen and Phosphorus Transport in the Lower Changjiang River before the Construction of the Three Gorges Dam. Estuarine, Coastal and Shelf Science 79(2): 239–250 doi:10.1016/j.ecss.2008.04.002

Duan, S. and T. S. Bianchi, 2007. Particulate and Dissolved Amino Acids in the Lower Mississippi and Pearl Rivers (USA). Marine Chemistry, 107: 214-229 doi:10.1016/j.marchem.2007.07.003

Duan, S.W., T. S. Bianchi, A. M. Shiller, K. Dria, P. Hatcher and K. R. Carman. 2007. Seasonal variations in abundance and bulk composition of dissolved organic matter in the Lower Mississippi and Pearl Rivers (USA). Journal Geophysical Research – Biosciences, 112: G02024, doi:10.1029/2006JG000206

Duan, S.W., F. Xu and L.J. Wang. 2007. Long-term changes in nutrient concentrations of the Changjiang River and principal tributaries. Biogeochemistry, 85: 215-234 doi: 10.1007/s10533-007-9130-2

Duan, S.W., T.S. Bianchi, and T.P. Sampere. 2007. Temporal variability in the composition and abundance of terrestrially-derived dissolved organic matter in the lower Mississippi and Pearl Rivers. Marine Chemistry, 103: 172-184 doi:10.1016/j.marchem.2006.07.003

Duan, S.W. and T. S. Bianchi. 2006.  Seasonal changes in the abundance and composition of plant pigments in particulate organic carbon in the lower Mississippi and Pearl Rivers (USA). Estuaries and Coasts, 29: 427–442.

Shiller, A. M., S.W. Duan, P. Erp and T. S. Bianchi. 2006.  Photo-oxidation of dissolved organic matter in river water and its effect on trace element speciation. Limnology and Oceanography, 51: 1716–1728.

Gong, G.C., J. Chang, K.P. Chiang, T.M. Hsiung, C.C. Hung, S.W. Duan and L. Codispoti, 2006. Reduction of primary production and changing of nutrient ratio in the East China Sea: Effect of the Three Gorges Dam? Geophysical Research Letters, 33, L07610, doi: 10.1029/2006GLO25800.

Dagg, M. J., T.S. Bianchi, G.A. Breed, W-J. Cai, S. Duan and et al., 2005. Biogeochemical characteristics of the lower Mississippi River, USA, during June 2003. Estuaries, 28: 664-675.

Shen, Zhang, H.B. Ji, W.J. Yan and S.W. Duan. Composition and flux of nutrients transport to estuary of the Changjiang River, Journal of Geographical Sciences, 2003, 13: 3-12.

Duan, S.W., S. Zhang and H. Huang, 2000.  Transport of dissolved inorganic nitrogen from the major rivers to estuaries in China.  Nutrient Cycling Agroecosystem. 57: 13-22.

Duan, S.W., S. Zhang and X.B. Chen, X.M. Zhang, L.J. Wang and W.J. Wan. 2000.  Concentrations of nitrogen and phosphorus and nutrient transport to estuary of the Yangtze River.  Environmental Science (Chinese), 21: 53-56.

Duan, S.W., and S. Zhang, 1999.  Seasonal variations of nitrogen and phosphorus concentrations in the Monitoring Stations of the Three Major Rivers in China, Geographical Science (Chinese), 19: 411-416.