Dr Robert Mortimer

Senior Lecturer: Environmental Geochemistry; Director of Student Education

Telephone number: +44(0) 113 34 35251
Email address: r.j.g.mortimer@leeds.ac.uk
Room: 8.106

Research Interests

I am an environmental geochemist interested in biogeochemical processes in sediments and their impact on water quality. My research spans a wide range of different problems and environments but the common theme is the use of innovative high resolution sampling and laboratory microcosm techniques. Ongoing/recent research includes:

• Phosphorus dynamics in rivers and wetlands.
• The role of bed sediments in controlling in-stream nutrient concentrations in rivers.
• The impact of river chemistry and suspended sediment on natural ecology and invading populations.
• The complexities of cycling of N, Mn, Fe and S in marine, estuarine, and freshwater sediments and wetlands.
• Occurrence and controls on anoxic nitrification in sediments.
• The impact of climate change on the dynamics of sediment redox and biogeochemical processes.
• Biogeochemistry of contaminant metals (chromium, uranium, technetium, lead, zinc, copper).
• Use of biogeochemistry to remediate nutrient and metal pollution in contaminated environments.
• The use of DET and DGT gel technology to make innovative measurements of the biogeochemistry of aquatic sediments.
• The use of DET and DGT to investigate tropical soil nutrient concentrations, with links to forest biodiversity.

Publications

• Burke, IT; Mortimer, RJG; Palani, S; Whittleston, RA; Lockwood, CL; Ashley, DJ; Stewart, DI (2012) Biogeochemical reduction processes in a hyper-alkaline leachate affected soil profile , Geomicrobiology Journal, .
• Whittleston, RA; Stewart, DI; Mortimer, RJG; Ashley, DJ; Burke, IT (2011) Effect of Microbially Induced Anoxia on Cr(VI) Mobility at a Site Contaminated with Hyperalkaline Residue from Chromite Ore Processing , Geomicrobiology Journal, 28, pp.68-82. doi:10.1080/01490451.2010.498297
• Palmer-Felgate, EJ; Mortimer, RJ; Krom, MD; Jarvie, HP; Williams, RJ; Spraggs, RE; Stratford, CJ (2011) Internal loading of phosphorus in a sedimentation pond of a treatment wetland: effect of a phytoplankton crash., Sci Total Environ, 409, pp.2222-2232. doi:10.1016/j.scitotenv.2011.02.034
• Palmer-Felgate, EJ; Mortimer, RJG; Krom, MD; Jarvie, HP; Williams, RJ; Stratford, CJ (2011) Internal loading of phosphorus in a sedimentation pond of a treatment wetland: effect of a phytoplankton crash., Science of the Total Environment, 409, pp.2222-2232.
• Clerici, SJ; Palmer-Felgate, EJ; Mortimer, RJ; Krom, MD; Jarvie, HP; Williams, RJ; Spraggs, RE; Stratford, CJ (2011) Response to Letter to the Editor "Aerobic phosphorus release from shallow lake sediments". , Sci Total Environ, 409, pp.4642-4643. doi:10.1016/j.scitotenv.2011.07.031
• Whittleston, RA; Stewart, DI; Mortimer, RJG; Tilt, ZC; Brown, AP; Geraki, K; Burke, IT (2011) Chromate reduction in Fe(II)-containing soil affected by hyperalkaline leachate from chromite ore processing residue, Journal of Hazardous Materials, 194, pp.15-23. doi:10.1016/j.jhazmat.2011.07.067
• Mortimer, RJG; Galsworthy, AMJ; Bottrell, SH; Wilmot, LE; Newton, RJ (2011) Experimental evidence for rapid biotic and biotic reduction of Fe (III) at low temperatures in salt marsh sediments: a possible mechanism for formation of modern sedimentary siderite concretions, Sedimentology, 58, pp.1514-1529. doi:10.1111/j.1365-3091.2011.01224.x
• Palmer-Felgate, EJ; Mortimer, RJG; Krom, MD; Jarvie, HP (2010) Impact of Point-Source Pollution on Phosphorus and Nitrogen Cycling in Stream-Bed Sediments, ENVIRON SCI TECHNOL, 44, pp.908-914. doi:10.1021/es902706r
• Bottrell, SH; Hatfield, D; Bartlett, R; Mortimer, RJG (2010) Concentration, sulfur isotopic composition and origin of organo-sulfur compounds in pore-waters of a highly polluted raised peatland., Organic Geochemistry, 41, pp.55-62.
• Imhoff, EM; Mortimer, RJG; Christmas, M; Dunn, AM (2010) Non-lethal tissue sampling allows molecular screening for microsporidian parastes in Signal (Pacifasticus leniusculus Dana) and White-Clawed Crayfish (Austropotamobius pallipes Lereboullet). , Freshwater Crayfish, 17, pp.145-150.
• Palmer-Felgate, EJ; Jarvie, HP; Withers, PJA; Mortimer, RJG; Krom, MD (2009) Stream-bed phosphorus in paired catchments with different agricultural land use intensity, AGR ECOSYST ENVIRON, 134, pp.53-66. doi:10.1016/j.agee.2009.05.014
• Fannin, C; Spraggs, R; Danes, P; Mortimer, R (2009) Wetland systems for the primary treatments of landfill leachate, Waste and Resource Management, 162, pp.75-83. doi:10.1680/warm.2009.162.2.75
• Bottrell, SH; Mortimer, RJG; Davies, IM; Harvey, SM; Krom, MD (2009) Sulphur cycling in organic-rich marine sediments from a Scottish fjord, SEDIMENTOLOGY, 56, pp.1159-1173. doi:10.1111/j.1365-3091.2008.01024.x
• Jarvie, HP; Mortimer, RJG; Palmer-Felgate, EJ; Quinton, KS; Harman, SA; Carbo, P (2008) Measurement of soluble reactive phosphorus concentration profiles and fluxes in river-bed sediments using DET get probes, J HYDROL, 350, pp.261-273. doi:10.1016/j.jhydrol.2007.10.041
• Mortimer, R; Krom, M (2008) The use of systems thinking software for research-led teaching of biogeochemical cycles: preliminary findings, Planet, 20, pp.21-25.
• Palmer-Felgate, EJ; Jarvie, HP; Williams, RJ; Mortimer, RJG; Loewenthal, M; Neal, C (2008) Phosphorus dynamics and productivity in a sewage-impacted lowland chalk stream, J HYDROL, 351, pp.87-97. doi:10.1016/j.jhydrol.2007.11.036
• Bartlett, R; Mortimer, RJG; Morris, K (2008) Anoxic nitrification: Evidence from Humber Estuary sediments (UK), CHEM GEOL, 250, pp.29-39. doi:10.1016/j.chemgeo.2008.02.001
• Bottrell, SH; Mortimer, RJG; Spence, M; Krom, MD; Clark, JM; Chapman, PJ (2007) Insights into redox cycling of sulfur and iron in peatlands using high-resolution diffusive equilibrium thin film (DET) gel probe sampling , CHEM GEOL, 244, pp.409-420. doi:10.1016/j.chemgeo.2007.06.028
• Bartlett, R; Mortimer, RJG; Morris, KM (2007) The biogeochemistry of a manganese-rich Scottish sea loch: Implications for the study of anoxic nitrification, CONT SHELF RES, 27, pp.1501-1509. doi:10.1016/j.csr.2007.01.027
• Stewart, DI; Burke, IT; Mortimer, RJG (2007) Stimulation of microbially mediated chromate reduction in alkaline soil-water systems , GEOMICROBIOL J, 24, pp.655-669. doi:10.1080/01490450701758221
• Burke, IT; Boothman, C; Lloyd, JR; Livens, FR; Charnock, JM; McBeth, JM; Mortimer, RJG; Morris, K (2006) Reoxidation behavior of technetium, iron, and sulfur in estuarine sediments, ENVIRON SCI TECHNOL, 40, pp.3529-3535. doi:10.1021/es052184t
• Fox, JR; Mortimer, RJG; Lear, G; Lloyd, JR; Beadle, I; Morris, K (2006) The biogeochemical behaviour of U(VI) in the simulated near-field of a low-level radioactive waste repository, APPL GEOCHEM, 21, pp.1539-1550. doi:10.1016/j.apgeochem.2006.05.006
• Lloyd, JR; Renshaw, JC; May, I; Livens, FR; Burke, IT; Mortimer, RJG; Morris, K (2005) Biotransformation of actinides: Microbial reduction of actinides and fission products , Journal of Nuclear and Radiochemical Sciences, 6, pp.17-20.
• Burke, IT; Boothman, C; Lloyd, JR; Mortimer, RJG; Livens, FR; Morris, K (2005) Effects of progressive anoxia on the solubility of technetium in sediments, ENVIRON SCI TECHNOL, 39, pp.4109-4116. doi:10.1021/es048124p
• Mortimer, RJG; Harris, SJ; Krom, MD; Freitag, TE; Prosser, JI; Barnes, J; Anschutz, P; Hayes, PJ; Davies, IM (2004) Anoxic nitrification in marine sediments , MAR ECOL-PROG SER, 276, pp.37-51.
• Mortimer, RJG; Krom, MD; Harris, SJ; Hayes, P; Davies, IM; Davison, W; Zhang, H (2002) Evidence for suboxic nitrification in recent marine sediments , Marine Ecology - Progress Series, 236, pp.31-35.
• Krom, MD; Mortimer, RJG; Poulton, SW; Hayes, P; Davies, IM; Davison, W; Zhang, H (2002) In-situ determination of dissolved iron production in recent marine sediments , AQUAT SCI, 64, pp.282-291.
• Harris, SJ; Mortimer, RJG (2002) Determination of nitrate in small water samples (100 mu L) by the cadmium-copper reduction method: A manual technique with application to the interstitial waters of marine sediments, INT J ENVIRON AN CH, 82, pp.369-376. doi:10.1080/0306731021000015038
• Zhang, H; Davison, W; Mortimer, RJG; Krom, MD; Hayes, PJ; Davies, IM (2002) Localised remobilization of metals in a marine sediment, SCI TOTAL ENVIRON, 296, pp.175-187.
• Konhauser, KO; Morris, K; Mortimer, RJG (2002) The role of microorganisms in sedimentary diagenesis: implications for radionuclide mobility, In: Keith-Roach, MK; Livens, FR (Ed) Interactions of Microorganisms with Radionuclides, Radioactivity in the Environment , 2, Elsevier: London, pp.61-100.
• Mortimer, RJG; Rae, JE (2000) Metal speciation (Cu, Zn, Pb, Cd) and organic matter in oxic to suboxic salt marsh sediments, Severn Estuary, Southwest Britain, Marine Pollution Bulletin, 40, pp.377-386.
• Mortimer, RJG; Hayes, P; Krom, MD; Davies, IM; Davison, W; Zhang, H; Phillips, CJ; Prosser, JI (2000) A new conceptual model for microbial processes in sediments, SET 2000 Special reception for young researchers, House of Commons, London, .
• Mortimer, RJG; Hayes, P; Krom, MD; Davies, IM (2000) Direct evidence of geochemical recycling within sedimentary biogeochemical zones, American Society of Limnology and Oceanography (ASLO), Copenhagen, Denmark, pp.SS42-12.
• Mortimer, RJG; Davey, JT; Krom, MD; Watson, PG; Frickers, PE; Clifton, RJ (1999) The effect of macrofauna on porewater profiles and nutrient fluxes in the intertidal zone of the Humber Estuary , Estuarine, Coastal and Shelf Science, 48, pp.683-699.
• Mortimer, RJG; Krom, MD; Boyle, DR; Nishri, A (1999) Use of a high-resolution pore-water gel profiler to measure groundwater fluxes at an underwater saline seepage site in Lake Kinneret, Israel , Limnology and Oceanography, 44, pp.1802-1809.
• Herut, B; Krom, MD; Pan, G; Mortimer, RJG (1999) Atmospheric input of nitrogen and phosphorus to the Southeast Mediterranean: sources, fluxes and possible impact , Limnology and Oceanography, 44, pp.1683-1692.
• Mortimer, RJG; Krom, MD; Watson, PG; Frickers, PE; Davey, JT; Clifton, RJ (1999) Sediment-water exchange of nutrients in the intertidal zone of the Humber Estuary, Marine Pollution Bulletin, 37, pp.261-279.
• Mortimer, RJG; Krom, MD (1998) New insights into biogeochemical processes from DET probes, Mineralogical Magazine, 62A, pp.1028-1029.
• Mortimer, RJG; Krom, MD; Hall, POJ; Hulth, S; Stahl, H (1998) Use of gel probes for the determination of high resolution solute distributions in marine and estuarine pore waters, Marine Chemistry, 63, pp.119-129.
• Mortimer, RJG; Coleman, ML; Rae, JE (1997) Effect of bacteria on the elemental composition of early diagenetic siderite: implications for palaeoenvironmental interpretations, Sedimentology, 44, pp.759-765.
• Mortimer, RJG; Coleman, ML (1997) Microbial influence on the oxygen isotopic composition of diagenetic siderite, Geochimica et Cosmochimica Acta, 61, pp.1705-1711.
• Krom, MD; Mortimer, RJG (1996) Report on work in Sea of Galilee, New Scientist, 152, pp.6.
• Whittleston, RA; Stewart, D; Mortimer, RJG; Ashley, DJ; Burke, IT (Not yet published) Effect of Microbially Induced Anoxia on Cr(VI) Mobility at a Site Contaminated with Hyperalkaline Residue from Chromite Ore Processing, Geomicrobiology Journal, .