The ability of Eichhornia azurea (Swartz) Kunth to clean water contaminated by thermotolerant coliforms

Abstract

In order to contribute with sustainable development, within the proposal to use biological systems for low-cost water treatments, proposing a natural and clean alternative, among the alternatives, bioremediation stands out, especially the phytoremediation technique with aquatic macrophytes. The objective of this work was to verify the capacity of water hyacinth Eichhornia azurea (Swartz) Kunth to clean water contaminated with thermotolerant coliforms. The research work was developed at the Microbiology Laboratory of the State University of Bahia (UNEB), Campus X, Teixeira de Freitas-BA. Initially, a collection of the species was carried out in the Itanhém River. After the adaptive period, specimens of the plant were distributed in four different tanks, each containing distinct characteristics of coliform contamination level. Weekly water collections were carried out from each tank for microbiological analysis. The data obtained were structured in tables and graphs, the method used to test the hypothesis of considerable difference between the treatment tanks and the time of loss of water contamination was the Variance Analysis using the Student's t-test. It was possible to observe the reduction of coliform populations present in the experimental tanks, where the mean decay of coliforms was 3.34895 log NMP/100 mL. In addition, the weight gain analysis of the plant specimens was performed, which reached an increment of up to 64 % in relation to the initial weight. The analyzed species presented potential for use in phytoremediation techniques.