Senecio bonariensis Hook. & Arn. promising arsenic phytoextractor from water in laboratory and field trials

Abstract

The use of plant species to cleanse groundwater with excessive concentrations of arsenic (As) derived from contact with weathered materials has become a valuable option to treat it. The aim of this work was to analyze the bioaccumulation capacity of As of Senecio bonariensis (Asteraceae) through controlled laboratory tests and uncontrolled trials in the field in order to generate a low cost method applicable in rural areas that do not have systems of water treatments. Plants collected from the natural environment were arranged in hydroponic crops under controlled and uncontrolled conditions, in the first case with increasing concentrations of As for 45 days, and in the second, with a constant concentration of As for a period in a range between 45 and 90 days. The plants were processed and dried for the measurement of As. In both tests, in all the samples there was a noticeable accumulation of As, generally greater in roots than in leaves. Under controlled conditions the plants accumulated more As in relation to greater concentration of this element in the water. In all the trials a high bioaccumulation of As was found, which turns the plant into a hyperaccumulator. Due to the ability of S. bonariensis to accumulate As, and even more because of the great biomass produced by this species, it becomes an excellent one to be used for the remediation of arsenical waters.