An analysis of the alterations of certain parameters in watercourses under various kinds of influence

Abstract

Rivers and streams receive several substances that alter the characteristics of the water, an effect that becomes more intense when the human population is close to the shore, performs some activity close to it, or dumps effluents from their activities in the watercourses. This project aims to evaluate the alteration of certain parameters in watercourses that are under variable influences, such as human populations, receiving effluents from an effluent treatment facility (ETF), and agriculture. The parameters investigated were: temperature (T), dissolved oxygen (DO), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total phosphorus (TP), organic phosphorus (OP), total Kjeldahl nitrogen (TKN), proteins (P), carbohydrates (C), and lipids (L). The resulting data pointed out that when considering all the parameters under analysis, the highest values (excluding DO) were found after the ETF released effluents. Another finding was that practically all parameters showed high coefficients of variation, which indicate the instability of the values of variables over time, and that the use of the Scott-Knott test was effective in sorting the average in the sample points.