Untersuchungen zum Methankreislauf in der Saale

Abstract

AbstractThe activities and interrelations of the processes of methanogenesis and methane oxidation were investigated in the water and sediment of the middle Saale River. The studies showed that in the impounded reaches of the river, which is heavily polluted by organic waste and inorganic compounds, sediments occur with high methane production rates (6.3–64.6 mmol/m2 · h). The methane oxidation in the surface sediment layer (20–240 μmol/1 · h) was shown to function as an effective barrier for the methane diffusion out of the sediment. The methane concentrations in the anaerobic sediment were very high (383–1696 μmol/1), but low in the water (0.33–9.3 μmol/1) in consequence of oxidation processes and water turbulence. The distribution of methane‐oxidizing bacteria was studied. High cell concentrations were found (water, 8.8 · 101 — 2.8 · 104 cells/ml; sediment, 1.3 · 106 — 1.3 · 107 cells/gram). The ecological importance of the processes of the methane cycle was evaluated by calculation of the oxygen demand (methane oxidation) and of the mineralization capacity in the river system. The anaerobic mineralization of organic matter with the methanogenesis as terminal step amounted to 59–87% of the total mineralization. The sediment and consequently the particular organic load was found to be a significant factor for estimation and control of the water quality in the river.