AN ASSESSMENT OF HEAVY METAL ACCUMULATION CAPACITY OF FIVE AQUATIC MACROPHYTES AND BIOCHEMICAL RESPONSE.

The phytoextraction capacity of five aquatic macrophytes (Eichhorniacrassipes,Hydrillaverticellata Pistia stratioties, Salviniamolesta and Lagenandra toxicaria) with respect to heavy metals like Ni, As, Zn, Cr and Fe were studied. It was done to study the plants capacity comparatively using monometallic system. Inorder to assess the biochemical response of the studied plants to heavy metal stress, metabolites like total carbohydrates, total soluble protein, tannin, total carotenoids, alkaloids, flavanoids, terpenoids, saponin and phenol were quantitatively estimated before and after treatment. With regard to Ni, As and Fe sample II showed maximum absorption and least by sample V. Zn absorption is greatest in plant sample II and least in sample I. As with Cr plant sample IV showed maximum absorption and least by sample I. The most significant biochemical change observed is the substantial increase in quantity of total carbohydrate, total soluble protein, total carotenoids, saponin and phenol content of the treated plants. Similarly there is a substantial reduction in metabolites like tannin, alkaloids, flavanoids and terpenoids after treatment. The studied macrophytes proved to the useful in the uptake of heavy metals in the monometallic system and showed great of potential for further applications in the industrial and waste water treatments.