Dynamical
dendrotoxicity and fate of nitroaromatic pollutants was quantified by experiments using newly developed glass fibre wick application
systems, which allowed the simultaneous measurement of growth and transpiration as
dendrotoxicity parameters.
Elimination
of disturbing leaching side effects and avoidance of flooding conditions was
achieved by a basal water (or test solution) supply via glass fibre wicks.
Planting shock could be excluded, because no transplanting was necessary.
Vitality
of the individual trees and uniformity in their physiological response was pre-tested by
gravimetrical measurement of transpiration the experiments were started.
Application systems and trees tested
Examples
for wick application systems for continuous or temporary pollutant supply are
illustrated in the following links:
-
Experimental design for individual measurements of
growth and evapotranspiration of trees, used for willow, poplar, Scots pine,
Norway spruce, birch, and others
-
8-pot-double
tray system: Salix example, used for willow and poplar
-
4-pot-double
tray system: Picea glauca example, used for Canadian white
spruce and Scots pine
-
Double-tray
system for longterm pollutant application to mature single trees, used
for willow, Norway spruce and Scots pine
Pollutants tested
Beside TNT, also important TNT concomitant substances were tested, like dinitrotoluenes
(2,4-DNT
and 2,6-DNT), trinitrobenzene (TNB), and aminodinitrotoluenes
(4-ADNT
and 2-ADNT).
Wick
supplied tree trays planted with Salix EW-13, Salix EW-20 and Populus
ZP-007 were examined for their ability to eliminate real contaminated leachate,
obtained from outdoor
experiments. Influence of contaminated leachate on transpiration and yield of the aboveground biomass was
compared with the effects of defined TNT
solutions and the respective pollutant free controls.
Pollutant analysis
After
a "soil recovery phase" of two weeks, after the application was
terminated, the fate of nitroaromatic compounds (NAC) in soil and plants was
estimated by GC-ECD analytics following an ethyl acetate extraction in an
ultrasonic bath.
Bio-testing of residual soil toxicity
Residual
toxicity of the soil was examined by means of a modified cress test (Lepidium
sativum).
Web
date: June 2002, last update: 13.02.04 19:12 by berndschoenmuth@yahoo.de
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