Details zur Publikation

Kategorie Textpublikation
Referenztyp Zeitschriften
DOI 10.1007/s11356-013-1685-y
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Titel (primär) Characterisation of microbial activity in the framework of natural attenuation without groundwater monitoring wells?: a new Direct-Push probe
Autor Schurig, C.; Melo, V.A.; Miltner, A. ORCID logo ; Kaestner, M.
Quelle Environmental Science and Pollution Research
Erscheinungsjahr 2014
Department UBT
Band/Volume 21
Heft 15
Seite von 9002
Seite bis 9015
Sprache englisch
Keywords Natural attenuation; Microbial degradation activity; Vadose zone; Direct-Push; BACTRAPs; In situ microcosms; Toluene; Aquifer; Groundwater monitoring well
UFZ Querschnittsthemen RU3;
Abstract At many contaminated field sites in Europe, monitored natural attenuation is a feasible site remediation option. Natural attenuation includes several processes but only the microbial degradation leads to real contaminant removal and very few methods are accepted by the authorities providing real evidence of microbial contaminant degradation activity. One of those methods is the recently developed in situ microcosm approach (BACTRAP®). These in situ microcosms consist of perforated stainless steel cages or PTFE tubes filled with an activated carbon matrix that is amended with 13C-labelled contaminants; the microcosms are then exposed within groundwater monitoring wells. Based on this approach, natural attenuation was accepted by authorities as a site remediation option for the BTEX-polluted site Zeitz in Germany. Currently, the in situ microcosms are restricted to the use inside groundwater monitoring wells at the level of the aquifer. The (classical) system therefore is only applicable on field sites with a network of monitoring wells, and only microbial activity inside the monitoring wells at the level of the aquifer can be assessed. In order to overcome these limitations, a new Direct-Push BACTRAP probe was developed on the basis of the Geoprobe® equipment. With respect to the mechanical boundary conditions of the DP technique, these new probes were constructed in a rugged and segmented manner and are adaptable to various sampling concepts. With this new probe, the approach can be extended to field sites without existing monitoring wells, and microbial activity was demonstrated to be measureable even under very dry conditions inside the vadose zone above the aquifer. In a field test, classical and Direct-Push BACTRAPs were applied in the BTEX-contaminated aquifer at the ModelPROBE reference site Zeitz (Germany). Both types of BACTRAPs were incubated in the centre and at the fringe of the BTEX plume. Analysis of phospholipid fatty acid (PLFA) patterns showed that the bacterial communities on DP-BACTRAPs were more similar to the soil than those found on classical BACTRAPs. During microbial degradation of the 13C-labelled substrate on the carrier material of the microcosms, the label was only slightly incorporated into bacterial biomass, as determined by PLFA analysis. This provides clear indication for decreased in situ natural attenuation potential in comparison to earlier sampling campaigns, which is presumably caused by a large-scale source remediation measure in the meantime. In conclusion, Direct-Push-based BACTRAPs offer a promising way to monitor natural attenuation or remediation success at field sites which are currently inaccessible by the technique due to the lack of monitoring wells or due to a main contamination present within the vadose zone.
dauerhafte UFZ-Verlinkung
Schurig, C., Melo, V.A., Miltner, A., Kaestner, M. (2014):
Characterisation of microbial activity in the framework of natural attenuation without groundwater monitoring wells?: a new Direct-Push probe
Environ. Sci. Pollut. Res. 21 (15), 9002 - 9015 10.1007/s11356-013-1685-y