NITROGEN AND PHOSPHORUS REMOVAL EFFICIENCY OF SWEET FLAG (ACORUS CALAMUS L.) FROM EUTROPHIC WATER

In the recent time, eutrophication is one of the major reasons for the degradation of surface water quality. Using biological agent to mitigate surface water eutrophication is environmentally sound and acceptable. Hydroponic experiment was carried out to study the effect of the aquatic emergent plant Acorus calamus L. on the removal of nitrogen (N) and phosphorus (P) in eutrophic water. The results showed that the plant height of A. calamus showed the highest growth (56.49 cm) when cultured at a mixed total nitrogen (TN) and P concentrations of 40 + 1.0 mg/l (C2). However, 53.4 cm growth of the hydroponic A. calamus was obtained at a mixed concentration of TN + P of 60 + 3.0 mg/l (C9). The N content of A. calamus leaves at C9 was the highest (0.659%). It showed a direct relationship with the increase in the N concentration of the hydroponic solution. The range of P content in dry matter of A. calamus leaves ranged from 0.311 - 0.501%. The average removal rate of N by A. calamus to three different concentrations of nitrogen treatment was 62.4, 66.2 and 69.7%, respectively. On the other hand, the average removal rate of N by A. calamus was recorded as 43.3, 52.8 and 62.0%, for three different concentrations of P treatments, respectively. At the 14th day of the experiment, the ammonia nitrogen removal rate of C9 treatment reached 81.0%, which was significantly higher than other treatments. But at the end of the experiment, the NO3-N removal rate of C9 treatment was the highest, reaching 27.4%, which was significantly higher than other treatments. Comprehensive analysis showed that A. calamus, treated at C9 grew well and had a better removal effect on N and P from the ambient experimental water.