Estudio comparativo de los efectos físicos causados por agua contaminada con sales de cromo en Lemna minor y Limnobium laevigatum.

Abstract

In the present research, a comparison was made in the physical effects caused of Lemna minor and Limnobium laevigatum by water contaminated with chromium (Cr) to know their potential as bioindicators and phytoremediators, for which they were exposed to water contaminated with dichromate of potassium in different concentrations (10 mg/L, 20 mg/L and 30 mg/L) with three repetitions of each one for a period of 60 days. Before the experimentation, the species were in an adaptation stage where they were supplied with a nutritious solution. For each sample there were available 9 liters of contaminated water with five plants of Limnobium laevigatum and in the case of Lemna minor with 45 gr in separate experimental units. These samples were placed in a greenhouse with temperature control and continuous oxygenation. The physical changes, such as changes in color, growth and vigor in the species used for the experimentation were recorded every 10 days, in addition, contaminated water analyzes were performed every 30 days. At the end of the experimental time it was determined that Limnobium laevigatum had undergone drastic color changes, decreased growth rate, lack of vigor and mortality in a greater range than Lemna minor. The percentage of Lemna minor chromium removal was 25.1% in the A treatment, 6.55% in B treatment and 3.96% in C treatment, while in Limnobium laevigatum it was 32.5% in A treatment, 11.55% in B treatment and 7.03% in C treatment. It is concluded that the best species to be used as bioindicator is Limnobium laevigatum and the best one as phytoremediator is Lemna minor. The use of Limnobium laevigatum is recommended in future researches since it is a specie with great bioremediation potencial and wich one does not show few studies.