Overview
Our research examines the biogeochemistry and hydrogeology of aqueous systems, with emphasis on the subsurface. Recent and ongoing projects in the group include:

• Variation in soil and groundwater biogeochemistry with land use across the Kansas aridity gradient
• Spatial and temporal variation in geochemistry and microbiology of the High Plains aquifer system, south-central Kansas
• Biogeochemical controls on microbial activity in anoxic environments
  
• Geochemistry as a tracer for fluid source in Cherokee Basin strata
• Geochemical controls on microbial methane formation in coal-bearing strata of the Cherokee Basin

Research approach and facility
We conduct both field and laboratory studies. In both cases, our research approach is to combine chemical analyses of water, gas, and solids with geochemical modeling calculations and analyses that directly examine microbial community composition. Students in the group, therefore, can gain experience with a broad range of techniques.

Our laboratory contains equipment needed for a variety of geochemical and microbiological tasks. It contains a dual-column gas chromatograph for analyzing gas composition (Gow Mac), an ion chromatography system capable of analyzing both cations and anions (Dionex), a UV Vis spectophotometer, an anaerobic chamber, a custom gas manifold for mixing gases and making anaerobic media, equipment needed for DNA extraction, and a fluorescence microscope for visualizing cells. Field equipment available in the laboratory includes a submersible pump for sampling groundwater and hand held pH, temperature, conductivity meters. More information about facilities available in the Department of Geology and on the K-State campus is available here.
 
​Peer-reviewed publications
Please check out Matthew Kirk's profile on Google Scholar.

Current and recent funding

• Collaborative Research: Biogeochemical drivers of interspecies electron transfer from iron reducers to methanogens (2018-2021)
• Microbiomes of Aquatic, Plant and Soil Systems (MAPS) Mediating Sustainability: An Observational and Experimental Network across Kansas. NSF RII Track-1 EPSCoR program (2017-2022)
• Seeding growth of a critical zone observatory for water research in Kansas. Kansas State University Water Seed Program (2016-2017) 
• Experimental and numerical modeling analysis of carbon dioxide as a control on microbial activity in anoxic environments. Kansas NSF EPSCoR First Awards in Climate or Energy Research program (6/2014 - 8/2015)
• Field study of fundamental controls on methane formation in a coalbed methane reservoir. American Chemical Society Petroleum Research Fund (8/2013 - 8/2017)
• Field trip to Costa Rica for educational and research activities. K-State International Incentives program (2013 - 2014)

Bacteria (green) growing in a porous medium column reactor experiment.

Sampling water and natural gas from a commercial gas well in Michigan.

Bioreactor experiments containing iron- and sulfate-reducing bacteria.