Combined effect of Fe2+ ions and the meta-isomer of dihydric phenol on duckweed

Abstract

The toxic effects of Fe2+ ions and resorcinol on Lemna minor in their joint presence in the aquatic environment were studied. The test response in the bioassay of solutions of Fe2+, resorcinol, and their mixtures was a violation of the permeability of duckweed membranes. This parameter was estimated from the change in the electrical conductivity of the aquatic medium in which the plant was placed, exposed to the toxicant in the acute experiment (30 min). It was found that the addition of both an equinormal concentration of Fe(II) (0.1n) and a five-fold deficiency (0.02n) to a 0.1n solution of resorcinol reduced the toxicity of resorcinol. Most likely, the effect obtained can be achieved by the formation of a new, less toxic compound (probably of a complex nature). The test used in the work, based on the assessment of the permeability of cell membranes under the action of toxicants, once again proved to be a promising tool for analyzing the combined toxicity of phenolic compounds and metal ions in relation to plant organisms.