Use of inductively coupled plasma optical emission spectrometry detection in determination of arsenic bioaccumulation in Trifolium pratense L. from contaminated soil

Abstract

Increment of arsenic (As) in soil, a highly poisonous element, is a considerably important issue nowadays due to its danger of entry to the environmental cycles and food contamination. Bioaccumulation properties of many plants have been studied, although a very few reveal as a proper bioaccumulator plant for As. The Red clover, Trifolium pratense L. geographically widespread. The aim was conducted in order to determine the potential ability of this plant for cleaning up contaminated soil. Food grown on such lands usually contains heavy metals. Phytoremediation treatment of the soil prevents their entry into food, because it reduces the concentration of pollutants. Eighty-five Red clover one month old plants were grown in a nursery until transplant into the contaminated soil by inorganic As. Leaves and roots of 60 of plants sample were taken separately in every ten day during 60 days and analysed by ICP-OES while 25 samples were kept in different pH (8-4) in contaminated soil samples. Mean values of inorganic As(V) and As(III) in shoots and roots of plants were determined, and the statistical approaches were used for establishing the differences Bioaccumulation factor was calculated for As contents of plant parts for every 10 days. The soil arsenic level (19.09 mg/kg) higher than the global average (10.0 mg/kg), but within the maximum acceptable limit for agricultural soil (20.0 mg/kg) recommended by the European Union after 10 days. The lowest mean arsenic concentration was found after 40 days of cultivation of plant in pH=6 (1.01 mg/kg). It was observed that Red clover had suitable ability for phytoextraction method and soil recovery more Arsenic in pH<7 after 20-30 days of growth. The rate of As uptake by Red clover was significantly affected by the grown days after cultivated in contaminated treated (p<0.05) and pH of soil while up-taking in pH≤6 (p-value <0.05).