Physicochemical analysis of wastewater discharge and impact on Ganges River of major cities of North India

The inadequate practice of discharge of wastewater into the receiving water bodies alters physicochemical parameters, which ultimately disturbs the livelihood of the aquatic flora and fauna. The present study was focussed on the evaluation of different technologies-based wastewater treatment plants efficiencies through analysing the physicochemical parameters of wastewater collected from each treatment step including inlet, outlet and downstream Ganges River in Prayagraj, Varanasi and Kanpur (India) during winter and summer seasons. The removal efficiency of the MBBR technology of Prayagraj WWTP was observed better than ASP and UASB technology of Varanasi and Kanpur respectively for both seasons. Correlation analysis explained strong negative correlation of pH and DO with nearly all the parameters of the study; whereas TDS, hardness, ammonia and BOD were highly correlated with each oxther in each city. The factor analysis suggested the best fit amongst the physicochemical parameters, with four factors elucidating 78.00% of the total variance, which further explained that DO, TDS, total alkalinity, nitrate, COD, and temperature were the major components for pollution. The results indicated that most of the samples were not appropriate for direct discharge into water bodies and irrigation purposes thus needed further implementation of advanced technologies in their treatment procedure.