Multiple Linear Regression Analysis to Identify Influential Water Quality Parameters of Dairy ETP

The focus of this study was the statistical analysis of the secondary treated water quality of SARAS dairy effluent treatment plant, Hanumangarh, Rajasthan and find the most influential quality parameters for rapid water quality monitoring. For this, wastewater quality index (WWQI) was computed using sixteen measured physicochemical parameters like temperature, pH, EC, COD, BOD, TA, TH, TDS, Na+, K+, Ca2+, Mg2+, Cl-, SO42-, NO3- and F- as per standard methods. The WWQI values for recreational and irrigation purpose range from 43.77 to 68.97, indicate excellent to good quality of treated water in terms of physicochemical parameters. Karl pearson correlation results indicated pairs COD-BOD, COD-WWQI, BOD-WWQI, pH– WWQI, TH – Ca2+, TH – Mg2+, TA - WWQI and NO3- - SO42- are observed with highly significant levels (0.8 < r < 1.0). The statistical method, multiple linear regression (MLR) analysis was performed using MS excel software to proportionate contribution of each independent variable to the overall variance. This analysis evaluated BOD as statistically the most significant with p-value < 0.05, so is sufficient to predict treated water quality.