Assessment of Seasonal Variation in the Water Quality Characteristics of Tuikual River, Aizawl, Mizoram

Tuikual river is a river that runs through Aizawl city, the river is known as Tuithum Lui just before joining the Tlawng river which is the main source of water supply in Mizoram. The research was conducted for a period of one year from October 2019 to September 2020 where the samples were collected at monthly intervals. The studied area has been divided into four sampling sites along the river from upstream to downstream. The river carries pollutants such as untreated city garbage, sewage discharges and biomedical effluents. The upstream Site 1 sample containing biomedical effluents from Aizawl Civil Hospital (the biggest hospital in Mizoram) and Site 2 sample containing biomedical effluents from Aizawl Civil Hospital and Ebenezer Hospital (a private hospital). The downstream Site 3 (known as Khawhpawp) and Site 4 (known as Tuithum) are tourist attraction that finally joins Tlawng River. Important water quality parameters namely Temperature, Dissolved Oxygen (DO), Biological Oxygen Demand (BOD), Acidity, Nitrite, Phosphate-P and Sulphate have been estimated for the study of seasonal variation of Tuikual River water quality. The results are computed on a seasonal basis i.e. Pre-monsoon (February-May), Monsoon (June-September) and Post-monsoon (October-January). The monsoon (rainy) season possessed higher values in all the studied parameters except for Dissolved Oxygen which may be due to the flow of heavy rainwater that carries a huge amount of pollutants from the surroundings into the river body of water. The findings were then compared with water quality standards given by USPH, BIS, WHO and ICMR. The correlation coefficient statistical analysis was done using Microsoft Excel. The investigation reveals that there is a significant seasonal variation in all the studied parameters.