Phytoremediation test of aquatic plant species in Lake Ledulu Rote Island (Indonesia) using neutron activation analysis

Ledulu Lake is one of the lakes in the Rote Ndao Region. Lake Ledulu was formed in the Quaternary period with Cenozoic constituents and Neogene deposits based on geological formations. The formations found in the Lake area are sediment, chemical, limestone. The purpose of this study was to measure the metal content in the lake water and its absorption by aquatic vegetation in the ecosystem of Ledulu lake, using Instrumental neutron activation analysis (INAA) technique. NAA is one of the modern methods that is able to measure the level of heavy metal uptake in aquatic biota (water animals and aquatic plants). The metal content in the water of the lake (mg/L) is: Bromine 405.06, Calcium 7,195.66, Cerium 9.10, Cobalt 2.43, Chromium 45.90, Lanthanum 12.07, Magnesium 1,189.93, Sodium 24,382.31. Aquatic plants that absorb heavy metals in lake Ledulu are Panicum sp, Ludwigia adscendens (L.) H.Hara, Ottelia alismoides (L) pers, Najas sp, Ipomea aquatica Forssk, Pontederia korsakowii (Regel & Maack) M.Pell. & C.N.Horn, Callitriche sp, Bacopa monnierii, and Nymphaea alba L. Sodium is not absorbed by Panicum sp, Ludwigia adsendence (L), and Nymphaea alba. Lanthanum is only absorbed by Panicum sp and Callitriche sp. All other elements can be absorbed by aquatic plants in the Ledulu lake ecosystem with different absorption concentrations.