Role of dominant macrophytes to treat Nambul river, the main polluter of Loktak – a dying Ramsar site in the Indo Burma hot spot (Manipur, India)
Creators: name: Thongam, Niteshwori
name: Meitei, Maibam Dhanaraj
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Space Science
subject: Biotechnology
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: FOS: Biological sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: Inorganic Chemistry

description: As a part of the monitoring process of the main polluting tributary of Loktak, the paper analyzed the water characteristics of the main polluted stretch of Nambul river i.e. Imphal Urban region. The results showed low pH (6.23 ± 0.32), high electrical conductivity (1373 ± 50.33 µSm<sup>−1</sup>), high turbidity (25.40 ± 0.90 NTU), poor dissolved oxygen content (0.53 ± 0.24 mgL<sup>−1</sup>), high nitrate, and phosphate concentrations (9.27 ± 0.40 and 2.05 ± 0.10 mgL<sup>−1</sup>, respectively). The Water Quality Index values indicate that Nambul river is unfit for drinking. Moreover, the Sodium Percentage, Sodium Adsorption Ratio, and Kelly’s Ratio revealed the unsuitable nature of the river for irrigation. Therefore, in order to clean the river water, lab scale microcosm experimentation was carried out to highlight the potential of the dominant macrophytes viz. <i>Eichhornia crassipes</i> (Mart) Solms and <i>Pistia stratiotes</i> (L.) as phytofilters. The results showed increased pH (7.6 ± 0.11 and 7.5 ± 0.1), higher dissolved oxygen content (5.87 ± 0.30 and 3.28 ± 0.30 mgL<sup>−1</sup>), less turbidity (0.60 ± 0.25 and 0.40 ± 0.15 NTU) and reduced nitrate and phosphate concentrations (0.37 ± 0.03 and 0.52 ± 0.01 mgL<sup>−1</sup>, and 0.534 ± 0.025 and 0.346 ± 0.01 mgL<sup>−1</sup>, respectively).Novelty statementThe present study showed the deteriorating water quality of Nambul river, the main polluting source of Loktak – a Ramsar site in the Montreux records.Water Quality Index calculated was above the unsuitable level for drinking at all the sampling locations in the Imphal Urban region.Sodium percentage, sodium adsorption ratio and Kelly’s ratio were above the desired limit, making the river water unfit for irrigation.Further, the microcosm experimentation showed that the dominant macrophytes viz. <i>Eichhornia crassipes</i> (Mart) Solms and <i>Pistia stratiotes</i> (L.) can control the pollution level of Nambul. The present study showed the deteriorating water quality of Nambul river, the main polluting source of Loktak – a Ramsar site in the Montreux records. Water Quality Index calculated was above the unsuitable level for drinking at all the sampling locations in the Imphal Urban region. Sodium percentage, sodium adsorption ratio and Kelly’s ratio were above the desired limit, making the river water unfit for irrigation. Further, the microcosm experimentation showed that the dominant macrophytes viz. <i>Eichhornia crassipes</i> (Mart) Solms and <i>Pistia stratiotes</i> (L.) can control the pollution level of Nambul.