Steve Comfort

Steve Comfort

  • Contact Information
  • My Story
  • Publications & Presentations
  • Background
  • Interests
  • Grants
  • Advising
  • Courses Taught
  • Outreach

Title Soil Environmental Chemist
Address 205 Kiesselbach Crop Research Laboratory
1870 North 37th Street
Lincoln NE
Phone 402-472-1502 & Lab 472-6540
FAX 402-472-7904
Vitae Download file

Hi, I'm Steve Comfort, a soil environmental chemist and professor in the School of Natural Resources (SNR).

I am associated with the water, geology, soils faculties in SNR and coordinate the Environmental Restoration Science major at UNL.

My interests are in understanding the fate and transport of organic chemicals in the environment and devising remediation strategies for contaminated soil and water.

Accidental spills and discharges of farm chemicals and industrial solvents take place each year. When these events occur, normally beneficial chemicals become sources of contamination for ground and surface water. Although the soil-water environment has an enormous potential to naturally attenuate (adsorb, degrade) these foreign substances, this capacity can be exceeded when chemicals are deliberately or inadvertently released to localized areas. To combat these point sources of contamination, our research attempts to devise treatments that can remove these contaminants or alter their chemical structure so that natural attenuation can proceed. Examples of our work include both field-scale treatment of pesticide-contaminated soils and the use of chemical oxidants to treat contaminated groundwater.

Our recent efforts are focusing on developing techniques to remove volatile organic compounds from low permeable zones in aquifers.

My primary teaching responsibility is devoted to teaching an undergraduate coutitled "Soils, Environment and Water Quality." This course is now being offered online for distance education. In the past, I have taught a graduate-level course titled 'Soil Environmental Chemistry." It involves outreach activities which provide in-depth training on the fate of chemicals in soils and groundwater - to individuals associated with pesticide application or installation of septic systems - in the state of Nebraska.

Steve Comfort
Steve Comfort
Treatment of DNAPL in low permeable zone. Click Here for larger image
In Situ Chemical Oxidation  of Contaminated Groundwater
In Situ Chemical Oxidation of Contaminated Groundwater
Field-Scale Treatment of  Pesticide-Contaminated Soil
Field-Scale Treatment of Pesticide-Contaminated Soil

Environmental Restoration Science Program (Major)

Student Project

Lindy Rauscher, an environmental restoration science major, worked with environmental chemist Steve Comfort and his graduate students on an award-winning UCARE project, investigating the use of permanganate to remediate PAH-contaminated water.

Lindy Rauscher poster

The video below follows Mandi Conway, an SNR undergraduate in Environmental Restoration Science, as she and graduate students help with a clean-up site in Cozad, Nebraska. Dr. Steve Comfort, ERS faculty, explains how the program gives students the skills to repair environmental damage.

Alumni Profiles

What can you do with a degree in Environmental Restoration Science? Recent graduate John Dinneen works for an environmental remediation company in Wisconsin and was recently in Sargent, Nebraska to work to remove harmful chemicals at a gas station site.

Slow-release Oxidant Candles

3-ft permanganate-wax candles
3-ft permanganate-wax candles
Candles placed in designated wells
Candles placed in designated wells
Candles inserted directly into formation via DPT
Candles inserted directly into formation via DPT

Traditional ISCO versus Aerated Oxidant Candles Injections

EPA Clean-Up Technology Webinar (03-21-2016)

EPA Clean Up Technology Webinar
View the webinar

Selected Publications

Kambhu, A., Gren, M., Tang, W., Comfort, S., Harris, C. (2017). Remediating 1,4-dioxane-contaminated water with slow-release persulfate and zerovalent iron. Chemosphere, 175, 170-177. Online
Christenson, M., Kambhu, A., Reece, J., Comfort, S., Brunner, L. 2016. A five-year performance review of field-scale, slow-release permanganate candles with recommendations for second-generation improvements. Chemosphere. 150:239-247. Online
Chainarong Sakulthaew, Steve D. Comfort, Chanat Chokejaroenrat, Xu Li, Clifford E. Harris. 2015. Removing PAHs from urban runoff water by combining ozonation and carbon nano-onions. Chemosphere, 141: 265-273 Online
Kananizadeh, N., C. Chokejaroenrat, Y. Li and S. Comfort. 2015. Modeling improved ISCO treatment of low permeable zones via viscosity modification: Assessment of system variables. J. Contam. Hydrol. 173: 25-37 Online
Chokejaroenrata, C., S.D. Comfort, C. Sakulthaew, and B. Dvorak. 2014. Improving the treatment of non-aqueous phase TCE in low permeability zones with permanganate. J. Hazardous Materials 268:177-184. Online
Huang,Yong H., Tian C. Zhang, Patrick J. Shea, and Steve D. Comfort. 2014. Competitive Reduction of Nitrate, Nitrite, and Nitrobenzene in Fe0-Water Systems. Journal of Environmental Engineering Aug 2014, Vol. 140, No. 8
Sakulthaew, Chainarong, Steve Comfort, Chanat Chokejaroenrat, Clifford Harris, and Xu Li. 2014. A combined chemical and biological approach to transforming and mineralizing PAHs in runoff water. Chemosphere, 117:1-9 Online
Chokejaroenrat Chanat, Negin Kananizadeh, Chainarong Sakulthaew, Steve Comfort, and Yusong Li. 2013. Improving the sweeping efficiency of permanganate into low permeable zones to treat TCE: Experimental results and model development. Environ. Sci. Technol. 47:13031-13038 Online
A. Kambhu, S.D. Comfort, C. Chokejaroenrat, and C. Sakultahew. 2012. Developing slow-release persulfate candles to treat BTEX contaminated groundwater. Chemosphere 89:656-664 Online
Christenson, M.D., A. Kambhu, and S.D. Comfort. 2012. Using slow-release permanganate candles to remove TCE from a low permeable aquifer at a former landfill. Chemosphere 89:680-687. Online
Halihan, T., J. Albano, S.D. Comfort, and V.A. Zlotnik. 2012. Electrical resistivity imaging of a permanganate injection during in situ treatment of RDX-contaminated groundwater. Ground Water Monitoring & Remediation 32:43-52. Online
Rauscher, Lindy, Chainarong Sakulthaew, and Steve Comfort. 2012. Using slow-release permanganate candles to remediate PAH-contaminated water. J. Hazard. Materials 241-242:441-449. Online
Chokejaroenrat, C., S.D. Comfort, C. Harris, D. Snow, D. Cassada, C. Sakulthaew, and T. Satapanajaru. 2011. Transformation of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by Permanganate. Environ. Sci. Technol., 45:3643-3649 Online
Kalderis, D, A. Juhasz, R. Boopathy, and S.D. Comfort. 2011. Soil contaminated by explosives - environmental fate and evaluation of state of the art remediation processes (IUPAC Technical Report). Pure and Applied Chemistry. 83:1407-1484 Online
Albano, J. S.D. Comfort, V. Zlotnik, T. Halihan, M. Burbach, C. Chokejaroenrat, S. Onanong, W. Clayton. 2010. In Situ Chemical Oxidation of RDX-Contaminated Ground Water with Permanganate at the Nebraska Ordnance Plant. Ground Water Monitoring & Remediation 30:96-106. Online
Boparai, H.K., S.D. Comfort, T. Satapanajaru, J.E. Szecsody, P.R. Grossl and P.J. Shea. 2010. Abiotic transformation of high explosives by freshly precipitated iron minerals in aqueous FeII solutions. Chemosphere, 79:865-872. Online
Satapanajaru, T.; Onanong, S.; Comfort, S. D.; Snow, D. D.; Cassada, D. A.; Harris, C., 2009. Remediating dinoseb-contaminated soil with zerovalent iron. Journal of Hazardous Materials, 168, (2-3), 930-937. Online
Waria, M.; Comfort, S. D.; Onanong, S.; Satapanajaru, T.; Boparai, H.; Harris, C.; Snow, D. D.; Cassada, D. A., 2009. Field-Scale Cleanup of Atrazine and Cyanazine Contaminated Soil with a Combined Chemical-Biological Approach. J Environmental Quality, 38, (5), 1803-1811. Online
Boparai, H.K., P.J. Shea, S.D. Comfort, and T.A. Machacek. 2008. Sequencing zerovalent iron treatment with carbon amendments to remediate agrichemical-contaminated soil. Water, Air and Soil Pollution.193:189-196. Online
Boparai, H.K., S.D. Comfort, P.J. Shea, and J.E. Szecsody. 2008. Remediating explosive-contaminated groundwater by in situ redox manipulation (ISRM) of aquifer sediments. Chemosphere 71:933-941. Online
Onanong, S. S.D. Comfort, P.D. Burrow, and P.J. Shea. 2007. Using gas-phase molecular descriptors to predict dechlorination rates of chloroalkanes by zerovalent iron. Environ. Sci. Technol.41:1200-1205. Online
Adam, M.A., S.D. Comfort, D.D. Snow, D. Cassada, M.C. Morley, and W. Clayton. 2006. Evaluating ozone as a remedial treatment for removing RDX from unsaturated soils. Journal of Environmental Engineering.132:1580-1588. Online
Boparai, H.K., P.J. Shea, S.D. Comfort, and D.D. Snow. 2006. Dechlorinating chloroacetanilide herbicides by dithionite-treated aquifer sediment and surface soil. Environ. Sci. Technol. 40:3043-3049. Online
Onanong, S., P.D. Burrow, S.D. Comfort, and P.J. Shea. 2006. Electron capture detector response and dissociative electron attachment cross sections in chloroalkanes and chloroalkenes. J. Phys. Chem. A 110:4363-4368. Online
Adam, M.L., S.D. Comfort, T.C. Zhang, and M.C. Morley. 2005. Evaluating Biodegradation as a Primary and Secondary Treatment for Removing RDX (Hexahydro-1,3,5-trinitro-1,3,5-triazine) from a Perched Aquifer. Bioremediation Journal 9:9-19. Online
Comfort, S.D. 2005. Remediating RDX and HMX Contaminated Soil and Water. In M. Fingerman and R. Nagabhushanam (eds) Bioremediation of Aquatic and Terrestrial EcoSystems. Science Publishers, Inc. Enfield, NH p. 263-310. Online
Park, J., S.D. Comfort, P.J. Shea, and J.S. Kim. 2005. Increasing Fe0-mediated HMX destruction in highly contaminated soil with didecyldimethylammonium bromide surfactant. Environ. Sci. Technol. 39:9683-9688. Online
Comfort, S.D., P.J. Shea, T.A. Machacek, and T. Satapanajaru. 2003. Pilot-scale treatment of RDX-contaminated soil with zerovalent iron. Journal of Environmental Quality. 32(5):1717-25. Online
Huang, Y.H., Zhang, T.C., Shea, P.J., Comfort, S.D. 2003. Effects of oxide coating and selected cations on nitrate reduction by iron metal. Journal of Environmental Quality. 32(4):1306-1315.
Satapanajaru, T., Comfort, S.D., Shea, P.J. 2003. Enhancing metolachlor destruction rates with aluminum and iron salts during zerovalent iron treatment. Journal of Environmental Quality. 32(5): 1726-34.
Smith, S.K., Franti, T.G., Comfort, S.D. 2002. Impact of initial soil water content, residue cover, and post-herbicide irrigation on atrazine and metolachlor runoff. Transactions of the ASAE. 45:1817-1824. Online
Comfort, S.D., Shea, P.J., Machacek, T.A., Gaber, H., Oh, B.-T. 2001.Field-scale remediation of a metolachlor spill site using zerovalent iron. Journal of Environmental Quality. 30:1636-1643 (Journal Series Number:13306) Online
Gorneau, W.S., Franti, T.G., Benham, B.L., Comfort, S.D. 2001. Reducing long-term atrazine runoff from south central Nebraska. Transactions of the ASAE. 44:45-52 (Journal Series Number:12677). Online
Oh, B.-T. Sarath, G., Shea, P.J., Drijber, R.A., Comfort, S.D. 2000. Rapid spectrophotometric determination of 2,4,6-trinitrotoluene in a Pseudomonas enzyme assay. Journal of Microbiological Methods. 42:149-158 (Journal Series Number:12803).
Bier, E.L., J. Singh, Z. Li, S.D. Comfort, and P.J. Shea 1999. Remediating hexahydro-1,3,5-trinitro-1,3,5-triazine-contaminated water and soil by Fenton oxidation. Environmental Toxicology and Chemistry. 18:1078-1084 (Journal Series Number:12206)
Kreslavski, V.D., G.K. Vasilyeva, S.D. Comfort, R.A. Drijber, and P.J. Shea 1999. Accelerated transformation and binding of 2,4,6-trinitrotoluene in rhizosphere soil. Bioremediation Journal. 3:59-67 (Journal Series Number:12333).
Singh, J., Comfort, S.D., Shea, P.J. 1999. Iron-mediated remediation of RDX-contaminated water and soil under controlled Eh-pH. Environmental Science and Technology. Environmental Science and Technology. 33:1488-1494 (Journal Series Number:12224) Online
Li, Z.M, P.J. Shea, and S.D. Comfort 1998. Nitrotoluene destruction by UV-catalyzed Fenton oxidation. Chemosphere. 36:1849-1865 (Journal Series Number:11825).
Peterson, M.M., G.L. Horst, P.J. Shea, and S.D. Comfort 1998. Germination and seedling development of switchgrass and smooth bromegrass exposed to 2,4,6-trinitrotoluene. Environmental Pollution. 99:53-59 (Journal Series Number:11968)
Singh, J., P.J. Shea, L.S. Hundal, S.D. Comfort, T.C. Zhang, and D.S. Hage 1998. Iron-enhanced remediation of water and soil containing atrazine. Weed Science. 46:381-388 (Journal Series Number:12032)
Singh, J., S.D. Comfort, and P.J. Shea 1998. Remediating RDX-contaminated water and soil using zero-valent iron. Journal of Environmental Quality. 27:1240-1245 (Journal Series Number:12001)
Singh, J., S.D. Comfort, L.S. Hundal, and P.J. Shea 1998. Long-term RDX sorption and fate in soil. Journal of Environmental Quality. 27:572-577 (Journal Series Number:11906)
Hundal, L.S., J. Singh, E.L. Bier, P.J. Shea, S.D. Comfort, and W.L. Powers 1997. Removal of TNT and RDX from water and soil using iron metal. Environmental Pollution. 26:896-904 (Journal Series Number:11703)
Hundal, L.S., P.J. Shea, S.D. Comfort, W.L. Powers, and J. Singh 1997. Long-term TNT sorption and bound residue formation in soil. Journal of Environmental Quality. 26:896-204 (Journal Series Number:11551)

Educational Background

  • BS - University of Wisconsin-Madison, Soil Science and Agricultural-Extension Education (1981)
  • MS - University of Minnesota, Soil Science (1984)
  • PhD - University of Wisconsin-Madison, Soil Science (1988)

SNR Program Area(s)

  • Environmental Science

Areas of Interest

  • Soil and Water Chemistry
  • Organic Chemicals
  • Fate and Transport of Remediation of Contaminated Soil and Water
  • Restoration
  • Environmental Restoration
  • Environmental Soil Analysis

Currently this page only displays grants that were awarded on 1/1/2009 to the present. If a grant was awarded prior to 1/1/2009 and is still active, it will not be displayed on this page.

Grant Title Predicitng the zone of influence of direct-push oxidant candles with aerators
Starting Date 7/1/2015
Principal Investigators
Steve Comfort
Yusong Li
Ending Date 6/30/2017
Funding Level $12,000.00
Funding Source Agricultural Research Division Graduate Research Assistant Support

Grant Title Testing of Direct-Push Candles
Starting Date 8/1/2014
Principal Investigators
Steve Comfort
Ending Date 10/31/2015
Funding Level $32,243.00
Funding Source Air Lift Environmental LLC

Grant Title STTR: Improving the Treatment of Contaminated Aquifers by Developing Direct Push Slowp Release Oxidant Candles with Pneumatic Circulators
Starting Date 9/12/2013
Principal Investigators
Steve Comfort
Ending Date 8/31/2014
Funding Level $49,450.00
Funding Source Air Lift Environmental LLC

Grant Title Cozad Contaminated Groundwater
Starting Date 10/22/2013
Principal Investigators
Steve Comfort
Ending Date 10/21/2018
Funding Level $12,500.00
Funding Source City of Cozad

Grant Title Nebraska Water Resource 104B 2011
Starting Date 3/1/2011
Principal Investigators
Steve Comfort
Ending Date 2/28/2015
Funding Level $12,000.00
Funding Source US Department of the Interior - Geological Survey


Undergraduate Majors Bachelor of Science in
  • Environmental Restoration Science
Graduate Program(s)

Master of Science in Natural Resource Sciences

Doctor of Philosophy in Natural Resource Sciences

Courses Taught
Course Number Course Title Fall Even Years Fall Odd Years Spring Even Years Spring Odd Years Summer Session Cross Listing
NRES 361 Soils, Environment and Water Quality X X AGRO/GEOL/NRES/SOIL/WATS 361
NRES 451 Soil Environmental Chemistry X X ENVE 451/851
NRES 851 Soil Environmental Chemistry X ENVE 451/851
NRES 996A Research in Soils X X X X AGRO 996A
WATS 361 Soils, Environment and Water Quality X X AGRO/GEOL/NRES/SOIL/WATS 361