Changes in nutrient concentration of Azolla (Azolla caroliniana) at various levels of arsenic and salinity

Rapid technological advances in recent decades despite the many benefits for human, exposed the natural resources and environmental components to various contaminants such as heavy metals. In order to evaluate the potential of Azolla, to absorb arsenic and nutrient from solution contaning different concentrations of salinity, a factorial experiment with completely randomized design and three replications were conducted in the greenhouse. Different levels of Arsenic were 0, 5, 10, 20, 40, 80 and 160 mg/liter. Arsenic was provided from source of sodium arsenate and was added to the Epestin food solution. The concentrations of NaCl in Epestin nutrient solutions were 0, 10, 20, 40 and 80 mM. Nutrient solutions with different concentration of arsenic and NaCl were used to growth azolla, for a period of 30 days. The result showed that existance of Arsenic heavy metal and salinity decreased the growth rate of azolla and even caused death where their concentrations were high. The azolla accumulated high concentration of arsenic solutions in their tissues. Assessing the effect of salinity on arsenic of the azolla indicated that increase in salinity levels of nutrient solution, decreased arsenic concentration. Arsenic increasing concentrations of calcium, sodium, manganese and decrease nitrogen, phosphorus, potassium, magnesium, iron, zinc and copper. Salinity treatments and mutual effects of arsenic and salinity treatments increased sodium and decreasing concentrations of nitrogen, phosphorus, potassium, calcium, magnesium, iron, zinc, manganese and copper.