Survey and remediation of TNT in groundwater, sediment and

Contamination survey and remediation of TNT in groundwater,
sediment and wastewater
Nehrenheim, E., Odlare, M., Ribé, V., Chusova, O., Eriksson, I., Eneroth, P.
Mälardalen University, Box 883, 721 23 Sweden, Remedy by Sweden AB, Structor
Miljöteknik AB, Norra Källgatan 17 722 11 Västerås
[email protected], +46739607403
Background
Ever since the world wars, production, use and disposal of ammunition has caused leachage
of explosives to the environment in Europe and former Soviet Union. Therefore, 2,4,6trinitrotoluene (TNT) and other nitroaromatic and nitramine compounds are commonly found
pollutants in soil, groundwater and sediments in the area. The substances are toxic and
some are carcinogenic. TNT is persistent in the environment due to its stability . It dissolves
partly in water (approximately 100 mg/L) under optimal conditions. We research the
presence, ecotoxicity and potential for remediation of TNT in groundwater. A project in
collaboration with the Swedish explosives industry - BIOREX, has been running at
Mälardalen University since 2008. BIOREX started as a development project to assist with
local remediation projects in Vingåker, Karlskoga and Lindesberg (Sweden). This paper is a
collection of the knowledge gained in the project. We present research results from field
surveys, analyses and ecotoxicity testing from the projects as well as some of our most
important achievments in developing new remediation methods. Further, this paper aims to
present yet unpublished experiences from some 7 years of on-site investigations.
Aim
The aim of the research is to i) determine the remediation need by assessing the gradients of
pollution (distribution of the contaminants) ), ii) complexity of contamination (e.g. explosives
and metals), iii) ecotoxicity and iv) potential remediation techniques. Sampling surveys was
conducted at the shooting range disposal site of Bofors Test Center in Karlskoga, from
wastewater treatment plant at the disposal factory in Vingåkersverken and at the Björkborn
Munition production site in Karlskoga.
Conclusion
TNT usually dissolves to a lower extent than the theoretical concentration; 60-70 mg/L is
more common to our experience. It has been found toxic to the test organisms Daphnia
Magna, Vibrio Fisherii, Heterocypris incongruens and inhibitory to the germination of
Lactuca sativa. Furthermore, it has shown a genotoxic effect in the Umu-C assay.. Sediment
and groundwater samples containing low concentrations of metals, TNT and its metabolites,
HMX and RDX, however, showed low to moderate hazard to test organisms. It could be
argued that synergetic effects are negligible from the substances. Our experiments also
showed that our cultivated inoculum increased the degradability of TNT and its metabolites.
TNT can be adsorbed to low cost adsorbents of organic materials, e.g. pine bark. If TNT is
partly degraded, it can be adsorbed by the amino structure of the pine bark surface and
subsequently become immobilized. During degradation of the pine bark surface, the pollutant
is simultaneously degraded and vanishes, i.e. it cannot be desorbed.

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