Corneliu Mihăiţă Pohonţu
Full Text PDF | fractal dimensions, landfill leachate, phytotoxicity, pollutants, poplar.
Toxicity testing represents one of the methods used in environmental technology with predictability in risk assessment. These have a great deal of efficiency in quantification of pollutants after its interaction with the biotic and abiotic environment as integral parts of an ecosystem. The study was conducted by assessed response of plants (Populus spp.) to phytotoxic compounds which can be interpreted by morphological and physiological parameters of test organism. Leaf length and, especially, fractal dimension are shown to be good indicators of plant response to toxicants in their environment. The source of toxic pollutants was landfill leachate the composition of which is very complex with a high degree of toxicity because it contains a diversified spectrum of heavy metal ions, ammonia, persistent organic pollutants or xenobiotic compounds. Plants were exposed to landfill leachate solutions. Phytotoxicological experiments were conducted during 4 weeks on the cuttings poplar (Populus spp.) using five successive concentrations of landfill leachate (6,25%; 12,5%; 25%; 50%; 100%), in triplicate and keeping the control of process with tap water representing 0% reference solution. The tolerance of plants was determined by quantification of morphological parameters of leaves including their fractal dimension simultaneously with to determine the range of values (LOEC) the lowest effective concentration causing toxic effects and (NOEC) no-toxic effect concentration. Digital images have been analyses using softwares in close correlation with the leaf fractal dimensions and the following leaf parameters: length, width, area, weight. It can be observed that with the increase of landfill leachate concentration determined increase in fractal dimension (Df) of cuttings poplar leaves.