Abstract

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⁻¹), high turbidity (25.40 ± 0.90 NTU), poor dissolved oxygen content (0.53 ± 0.24 mgL⁻¹), high nitrate, and phosphate concentrations (9.27 ± 0.40 and 2.05 ± 0.10 mgL⁻¹, 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. Eichhornia crassipes (Mart) Solms and Pistia stratiotes (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⁻¹), 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⁻¹, and 0.534 ± 0.025 and 0.346 ± 0.01 mgL⁻¹, respectively).

• Novelty statement

• 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. Eichhornia crassipes (Mart) Solms and Pistia stratiotes (L.) can control the pollution level of Nambul.

摘要

作为Loktak主要污染支流监测过程的一部分，本文分析了Nambul河主要污染段即Imphal Urban地区的水体特征。结果显示低 pH (6.23 ± 0.32)、高电导率 (1373 ± 50.33 µSm ^-1 )、高浊度 (25.40 ± 0.90 NTU)、溶解氧含量差 (0.53 ± 0.24 mgL ^-1 )、高硝酸盐和磷酸盐浓度（9.27 ± 0.40 和 2.05 ± 0.10 mgL ^-1， 分别）。水质指数值表明南布尔河不适合饮用。此外，钠百分比、钠吸附比和凯利比揭示了河流不适合灌溉的性质。因此，为了清洁河水，进行了实验室规模的微观实验，以突出优势大型植物的潜力，即。Eichhornia crassipes (Mart) Solms 和Pistia Stratiotes (L.) 作为植物过滤器。结果显示 pH 值升高（7.6 ± 0.11 和 7.5 ± 0.1），溶解氧含量升高（5.87 ± 0.30 和 3.28 ± 0.30 mgL ^-1），浊度降低（0.60 ± 0.25 和 0.40 ± 0.15 NTU），硝酸盐和磷酸盐浓度降低(0.37 ± 0.03 和 0.52 ± 0.01 毫克升^-1，分别为 0.534 ± 0.025 和 0.346 ± 0.01 mgL ^-1）。

• 新颖性声明

• 目前的研究表明，Nambul 河的水质正在恶化，Loktak 是蒙特勒记录中的拉姆萨尔湿地的主要污染源。

• 在英帕尔市区的所有采样点，计算出的水质指数均高于不适宜饮用的水平。

• 钠含量、钠吸附率和凯利比均高于预期限值，使河水不适合灌溉。

• 此外，微观实验表明，主要的大型植物即。Eichhornia crassipes (Mart) Solms 和Pistia stratiotes (L.) 可以控制 Nambul 的污染水平。