NATIVE MACROPHYTES AS METAL BIOMONITORS IN PERI-URBAN WETLANDS

HADAD, H.R.; NOCETTI, E.; MAINE, M.A.; MUFARREGE, M.M.; DENARO, A.; DI LUCA, G.A.; CAMPAGNOLI, M.A.

Viena

Simposio; 9th International Symposium on Wetland Pollutant Dynamics and Control, WETPOL 2021; 2021

University of Natural Resources and Life Sciences, Vienna (BOKU)

The aim of this work was to evaluate the use of different native macrophytes as metal biomonitorsin peri-urban wetlands (Santa Fe city, Argentina). Plants, water, and sediment were collected insampling points located near of urban centers and roads during year 2018. The study sites werechosen according to signs of environmental degradation, e.g., closeness to urban areas and roads,and pipe dump of unknown origin. They study sites were: Rincon city, an industrial park, an urbanecological reserve (UER), a university campus, and Leyes village. The following dominantmacrophytes were studied in each site: 1) Rincon: Typha domingensis, 2) industrial park: Typhadomingensis, 3) UER: Typha domingensis-Panicum elephantipes, 4) university campus: Cannaglauca, 5) Leyes: Pontederia rotundifoliaPlants were sampled by hand and metal measurements were carried out in aerial and submergedparts of leaves, roots and rhizomes. Water samples were collected in triplicate using plastic bottles.A 3-cm diameter PVC corer was used for the sampling of surface sediment at a depth ofapproximately 10 cm. A preliminary multi-elemental screening was carried out in the samples ofwater, plant tissues, and sediment by inductively coupled plasma emission spectroscopy (ICP).According to these results, the main metals found Cr, Ni, Zn, and Pb were studied. During thestudy, for the determination of metals in water, plant tissues and sediment, samples were treatedaccording to EPA method 200.2 and analyzed by atomic absorption spectrometry.In water, the industrial park showed the highest values of Cr and Pb, while Cr also was detected inUER. Although the UER is a protected site, it was observed that receives run-off from a near sportspark. In sediment, the industrial park and Leyes showed the highest Cr and Zn concentrations.However, all metal concentrations in plant tissues from the industrial park were the highest, and P.rotundifolia plants from Leyes showed the highest Pb root tissue concentrations. These resultsindicates that the studied metal concentrations are not correlated between water, sediment, andplant tissues, demonstrating that macrophytes are better indicators of metal presence thanenvironmental compartments. The plant morphology and the different propagation ways areimportant characteristics in the acquisition and accumulation of metals. The species that present ahigh biomass, such as T. domingensis, are efficient contaminant bioaccumulators. The submergedparts of leaves accumulate a remarkable amount of contaminants followed by roots. Due to thesetissues are in direct contact with water, metals are accumulated mainly by adsorption on theepidermis. Native macrophytes are efficient bioaccumulators and biomonitors for metals.Therefore, designing successful biomonitoring and bioassessment programs are an importantbasis for the rehabilitation and restoration of aquatic ecosystems. It is necessary to carry out furtherstudies focused in different plant species and contaminants. These studies could contribute to theknowledge of plant mechanisms of contaminant accumulation in treatment wetlands.