The effects of alginate microspheres on phytoremediation and growth of Lemna minor in the presence of Cd

Abstract

Today, the removal of increased amount of contaminant concentrations in nature such as metals, nanoparticles, has become an essential issue to struggle with. In this paper, both the toxic effects of non-essential Cd on Lemna minor in presence of alginate microspheres and metal removal capacity of Cd-exposed L. minor and microspheres were investigated. Three test groups were constructed: group (L) containing Lemna, group (M) containing alginate microsphere and group (L+M) containing alginate microsphere and Lemna. Five different levels of Cd concentrations were added into these groups. Estimation models were constructed to estimate Cd removal capacities of L. minor and microspheres, and time-concentration-dependent growth (GRC) rates of both microsphere-containing and non-containing groups were modelled by regression analysis. It was seen that microspheres alone only had no positive or negative effects on Lemna growth. It was observed that, for all test groups the time-dependent growth rate has both increase-decrease trends in general. The toxicity effect of Cd on Lemna growth was reduced by adding microspheres into medium. Furthermore, the results stated that test groups containing only microspheres (M, 0-97.56%) and consortium groups (M+L, 0-98.26%) were slightly more successful in Cd removal process compared to Lemna (L) groups (L, 0-97.32%).