Prediction of Water Quality of a Stream Carrying Industrial Treated Waste Water Using QUAL2K

Abstract

Water is essential to life, and its contamination affects all living beings on earth. Dissolved oxygen (DO), Biochemical Oxygen Demand (BOD), pH are some of the most important water quality parameter not only for human beings but also for the survival of aquatic life. Discharge of organic, industrial, agricultural, biodegradable wastewater into rivers, results in decrease of DO concentration and increase of BOD concentration in downstream waters. In this work, we have considered point sources of pollution and their effect on the river water quality. Qual2K model is used for analysis of river water quality. The water quality parameters included in the model were DO, BOD, among others. In real situations, the water quality monitoring stations are located at some distance and many point sources might discharge water into the river between two monitoring stations. In such situations, the contributions of the various point sources to the degradation in water quality become difficult to ascertain. The QUAL2K model has proved to be especially useful in predicting the impact of point sources on DO in downstream water quality. The experiments for the study were chosen using statistical designs. The values of various parameters were considered at various points along the stretch. The model was run with the values of two-point source discharges and head water. The water quality was predicted for a point at a distance from the last sampling point. The results predicted by the model were validated by testing the water quality at five points along the stretch. The data from simulations were analyzed using analysis of variance (ANOVA) and explicit and implicit regression models were obtained to explain the data using simple equations.