Microcosms-experiments to assess the potential for natural attenuation of contaminated groundwater.
Groundwater samples from six wells of a former gas plant site were characterised using chemical, microbial and ecotoxicological methods. Degradation studies were performed in batch-culture under aerobic conditions with the groundwater samples containing their autochthonous microflora and original contaminant mixture. The highest O2-consumption (3 mmol 100 ml-1), combined with BTEX (8.3 mg l-1) and naphthalene (171.3 mg l-1) degradation, as well as formation of organic acids was found after N- and P-supplementation with the highest contaminated groundwater sample. The other highly polluted groundwater sample showed no activity obviously because of the toxicity of some compounds. The major part of the PAHs and BTEX was eliminated in the assays with the low contaminated groundwater samples. The results indicate that the microbial degradation capacity and thereby the natural attenuation capacity in each groundwater differ and cannot be assessed simply by chemical, microbial and toxicological data. Additionally activity tests with authentic groundwater samples with and without nutrient supplementation are recommended.
Institute of Hygiene and Environmental Medicine, RWTH Aachen, Pauwelsstrasse 30, D-52074 Aachen, Germany.
K
K
Althoff
M
M
Mundt
A
A
Eisentraeger
W
W
Dott
J
J
Hollender
D002245:Carbon Dioxide / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D005858:Germany; D006863:Hydrogen-Ion Concentration; D008832:Microchemistry; D009281:Naphthalenes; D010100:Oxygen / Q000032:analysis; D010101:Oxygen Consumption; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D014881:Water Supply
D009281:Naphthalenes; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; D002245:Carbon Dioxide; C031721:naphthalene; D010100:Oxygen