Abstract:
Phytoremediation is the use of aquatic plants to decrease, extract or remove organic and inorganic
compound from the water and soil. Removal of nutrients such as nitrogen and phosphorus, reduces
the adverse impacts on the aquatic ecosystem. This study was conducted for 28 days to investigate
the phytoremediation potential of Ipomoea aquatica in carp rearing water. The experiment was
consisted with two different stocking densities of Kangkong plants as 6 PT (6 plants/tanks with fish),
9 PT (9 plants/tanks with fish) and C (control–only fish without plant). Cyprinus carpio var. koi
(3.85±0.05 cm and 0.80±0.04g) were stocked at the stocking density of 08 fish/tank. Kangkong
seedlings (height-13.00±1.80 cm) were potted and fixed into floating Styrofoam raft. Fish were fed
twice a day at the rate of 5% BWt/day for the first two weeks and then 7% BWt/day. No significant
difference was found among the treatments for growth parameters of fish. Ammonia levels of 9 PT
(0.14±0.07 mg/L) and 6 PT (0.16±0.08 mg/L) were significantly lower than that of the control
(0.52±0.48mg/L) at the end of the study period. Nitrite (1.5±0.00) mg/L and nitrate (1.67±0.08)
mg/L levels did not show any significant difference between the treatments. The phosphate
concentration was significantly higher in 9 PT (0.80±0.03 mg/L) than 6 PT and control. No significant
differences were found among treatments for plant height (cm), shoot length (cm), root length (cm),
number of leaves, % shoot length, % root length, plant dry weight (g), root dry weight (g), and total
biomass (g). However, wet weight of plants, shoots and % weight gain, shoot dry weight (g) and
surface area of the leaves (cm2) were significantly higher in 6 PT and % root dry weight is
significantly higher in 9 PT than 6 PT. Based on the results of plant growth parameters and water
quality parameters, 6 PT could be recommended as the best stocking density for the
phytoremediation purpose.
