Abstract
River Ganges (locally called as river Ganga) is one of the most scared rivers in India. The river is symbol of hope, faith and is worshipped for its wholesomeness due to its purity and sanctity. Pollution of river water due to anthropogenic activity is a very common issue worldwide. Similarly, river Ganga pollution in India throughout its entire courses, is a major concern due to city outfalls. This river, also named as river Hooghly in West Bengal, India, is exposed to outfalls carrying domestic wastewater of its both bank and their distribution in river Ganga is strongly influenced by season and tide. This study aimed to generate an idea of distance and direction wise changes of concentration of pollutants in wastewater in river Ganga. During 2014, the selection of five major outfalls was done by considering Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), heavy metals, total fecal coliform level, and the study continued for next four consecutive years to find out the influence of tide and season. Geographical Information System (GIS) based maps provided a better reflection of these changes. Student’s t-test highlighted the significant changes in concentration of parameters season wise. A significant higher value of DO, BOD, nitrate nitrogen, and chloride were found in pre-monsoon season compared to monsoon season. Regression Equation generated for highly correlated parameters (coliform and heavy metals) helped to predict the level of one parameter with others. The zone of influence of BOD, DO, phosphorus and nitrate nitrogen from each of the five selected outfalls was very prominent. Acoustic Doppler current profiler at two of the five outfalls helped to estimate strip-wise depth average discharge which helped to estimate the value of water quality parameters by Plug Flow Model during high tide and low tide. A strong tidal variation was observed during low tide. This study helped to predict the influential zone from outfalls which will help to generate an alternative solution of river water use. This approach can be applied globally to prepare river water usage guidelines.
Highlights
River Ganges, one of the most sacred rivers in India, travels through West Bengal spanning around 570 km
Parameters like color, odor, pH, temperature, and Dissolved Oxygen (DO) were analyzed in the field immediately
The unpleasant odor may be due to the presence of metals, salts, alkaline materials, and end product of biological reactions [40, 41]
Summary
River Ganges (locally called as river Ganga), one of the most sacred rivers in India, travels through West Bengal spanning around 570 km. Tidal nature of the river influences countryside discharge draining into the Bay of Bengal [1]. River Ganga in West Bengal is tidal in nature and its effect stretches up to Nabadwip [2]. Low tide and high tide prevail in river and influence the dispersion of pollutants from different discharge points. High tide increases water level and reach above the invert level of the drains near the mouth which results into backflow of river water into drains. The tidal nature of river has an influence on changing concentration of pollutants releasing into the river through the outfalls directly connected to the river alongside its bank. The nature of tide, direction of the flow of water, and volume of water in the river among others are the main reason behind this change
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
