Pilot testing of a bioremediation system for water and soils contaminated with heavy metals: vegetable depuration module

CERIONI, J; GODEAS, ALICIA MARGARITA; SILVANI, VANESA ANALÍA; BENAVIDEZ, MATÍAS; SCOTTI, ADALGISA; VISCIGLIA, M

Encuentro; XIV Encuentro Internacional Ciencias de la Tierra; 2019

ICES, CNEA, UNCUYO

We present a novel constructed wetland called a vegetable depuration module (VDM) as a pilottest of a bioremediation system (BS) for decontaminating water and soil polluted with heavy metals. The VDM consisted of a pool filled with stones of different granulometry and a substrate top layer composed of a mixture of soil and volcanic ash (50:50, v/v) supplemented with 350ppm Zn. The BS of sunflower plants colonized by the arbuscular mycorrhizal fungus Rhizophagus intraradices was planted in the VDM. Initially, the substrate registered high concentrations of Zn, Cr, Mn, Cu, and Sr, and had Eh > +500mV and pH 8.4. Irrigation with a Cu solution by vertical flow was carried out. After 3months, bioaccumulation factors ranged from 1.00 to 8.90, and translocation rates were >1 for Sr and Cu. Total metals extracted by the BS and percolation were 31%, 34%, 50%, 45%, and 57% for Zn, Cu, Mn, Cr, and Sr, respectively. Only the BS was capable of extracting 94% of Cu and 38% of Zn. VDM allowed us to calibrate the extractive performance of the studied elements in BS. This biotechnological development holds great potential for phytoremediation of polluted areas.