The Self Purification Model for Water Pollution

Abstract

ABSTRACT : Mathematical model have been developed for self purification of river water. Since the ecology of the river depends largely on the quantity of dissolved oxygen in its water, this dissolved oxygen (DO) seems to be a convenient criterion for measuring the degree of pollution of a river as far as organic pollution is concerned. However, even the term organic pollution embodies a great number of different materials and the question assessing this load of pollutants is raised.Considering that the effect of all kinds of organic matter will be consumption of dissolved oxygen, it is usual to measure the load of organic pollution by the quantity of oxygen necessary to completely oxidize this load by bacteriological breakdown, i.e. by its biological oxygen demand (BOD).The present analysis deals with the polluted water in a river. Mathematical models is formulated which simulates the variations of the parameters D = DO (Dissolved oxygen and B = BOD (Biological oxygen demand) over time at each point of a river (or reach of a river).The validity of the prospection use of the model depends heavily on the validity of the equations which have been used and this depends on knowledge of accurate hydrolic parameters advection, diffusion and reaeration. These parameters are fairly well known by a theoretical approach when compared to biodegradation and other phenomena. A details comprehensive field measurement survey is necessary to determine empirically the bulk biodegradation coefficients to be introduce into the model. Under these conditions a complete understanding of the mechanism of self purification can be obtained. This mathematical models is very helpful for the study of oxygen in rivers.