PHYTOREMEDIATION OF CHROMIUM BY Eichhornia crassipes AND Pistia stratiotes PLANTS APPLIED AS SINGLE SPECIES AND IN COMBINATION AND EFFECTS ON THE GROWTH, PHYSIOLOGY, AND ANATOMY OF BOTH SPECIES

• Main Author: ERRY TAKENE - NIM: 20615002 , DEOROSARI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/26502
• Institution: Institut Teknologi Bandung

<p align="justify">Eichhornia crassipes and Pistia stratiotes are plant species with potential to absorb heavy metals like chromium (Cr) and act as phytoremediation agents; however, the effects of Cr absorption and accumulation on their growth, physiology and anatomy have not been widely studied. The objectives of this study were to: (1) determine the effectiveness of Cr absorption and accumulation by E. crassipes and P. stratiotes, applied separately as single species and in combination; and (2) evaluate the physiological, anatomical and growth responses of each phytoremediation agent. Treatments were administered by exposing plants, both as single species and in combination, to hydroponic media containing K2Cr2O7 as simulated waste with Cr concentration of 7 mg L-1. A solution of K2Cr2O7 without addition of plants was used as comparison (control). To observe physiological and anatomical effects, plants were also grown in media without K2Cr2O7 addition. Cr concentration in growing media and the rate of change in concentration were measured every three days for 15 days. After the retention period, plant parameters measured include Cr accumulation in root and shoot, physiology (chlorophyll and proline), anatomy and growth (wet and dry weight). Results showed that the remaining Cr in media was lowest in the combination species treatment, i.e., about 3 mg L-1 with a decrease rate of 6.30% per day. The decrease in Cr concentration within growing media of single and combination species treatments was significantly different from control without plants (p<0.05). Cr accumulation was higher in roots than in shoots, and highest accumulation was recorded in the combined species treatment, i.e., 10,582 mg kg-1. Results of chlorophyll measurements showed lower content in plants exposed to Cr, with the most difference in P. stratiotes, both in single and combination treatments; the final content of 1 mg g-1 was significantly different from control (p <0.05). Proline level was higher in leaves than in roots; the highest concentration was found in leaves of P. stratiotes, i.e., 8.53 &#956;g g-1 which was significantly different from control (p <0.05). Cr exposure affected anatomical changes in cells and root tissues, including the length and number of layers of outer, inner, and overall cortical cells; length of aerenchyma and width of intercellular space in the aerenchyma; size of endodermis cell, and diameter of the xylem trachea. Generally, it can be concluded that the application of combined species treatment can absorb more Cr than single species. The accumulation of Cr in plants leads to decreased chlorophyll content, increased leaf proline, changes in tissue anatomy, and reduction in wet and dry weight. <p align="justify">