Monitoring and interpretation of H2 as a redox indicator in an anaerobic leachate plume

Concentrations of hydrogen (H2)was measured in 52 sampling points in the leachate pollution plume at the Grindsted Landfill. The H2 concentrations indicate that the redox level of the main part of the strongly anaerobic plume is iron-reducing. Calculation of Gibb's free energy for various redox processes at the actual groundwater temperature of 8 degrees C suggests that sulfate-refuction may also take place, but that methanogenesis must take place in microniches or by fermentation since the free energy and the H2 levels are not favorable for carbondioxide reduction. These results are in accordance with the microbial studies performed in the plume. Prior to the study, testing of well construction and materials was performed to
allow for correct measurements to be made.