Sulphur transformation and deposition in the rhizosphere of Juncus effusus in a laboratory-scale constructed wetland.
Sulphur cycling and its correlation to removal processes under dynamic redox conditions in the rhizosphere of helophytes in treatment wetlands are poorly understood. Therefore, long-term experiments were performed in laboratory-scale constructed wetlands treating artificial domestic wastewater in order to investigate the dynamics of sulphur compounds, the responses of plants and nitrifying microorganisms under carbon surplus conditions, and the generation of methane. For carbon surplus conditions (carbon:sulphate of 2.8:1) sulphate reduction happened but was repressed, in contrast to unplanted filters mentioned in literature. Doubling the carbon load caused stable and efficient sulphate reduction, rising of pH, increasing enrichment of S(2-) and S(0) in pore water, and finally plant death and inhibition of nitrification by sulphide toxicity. The data show a clear correlation of the occurrence of reduced S-species with decreasing C and N removal performance and plant viability in the experimental constructed wetlands.
Department of Bioremediation, Helmholtz Centre for Environmental Research-UFZ, Permoserstrasse 15, 04318 Leipzig, Germany.
A
A
Wiessner
P
P
Kuschk
M
M
Jechorek
H
H
Seidel
M
M
Kästner
D001673:Biodegradation, Environmental; D002244:Carbon / Q000378:metabolism; D004463:Ecology / Q000295:instrumentation / Q000379:methods; D006863:Hydrogen-Ion Concentration; D009584:Nitrogen / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*; D013995:Time; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism*; D053833:Wetlands
D014874:Water Pollutants, Chemical; D013455:Sulfur; D002244:Carbon; D009584:Nitrogen