Avaliação de parâmetros físicos-químicos e fitotoxicidade das águas do Córrego Paragem

Abstract

The stream Paragem is born south of the city of Dourados and crosses the urban and agricultural areas of the municipality. Its environment presents intense occupation, being subject to the most diverse environmental impacts. However, another complicating is the occupations and irregular ocuppancy that occur to a great extent of the stream. The present study had as objective to analyze the water quality at four points of the stream stops, with emphasis on physical-chemical analysis and phytotoxicity through germination and elongation Lactuca sativa. Four sampling points were selected, being two controls that are groundwater and osmosis water, in which water samples collected in April, May, and June of 2018. Water analysis consisted of pH, electrical conductivity, Redox Potential, turbidity, total solids, total dissolved solids, ammonia, as well as Principal Component Analysis and hierarchical analysis of the data. The phytotoxicity of the water samples was evaluated using the length of root and hypocotyl of the Lactuca sativa seedlings. Box tests followed by Tukey tests were used for the analysis of variance of root and hypocotyl lengths obtained at each sampling point. The sites studied Nascente, Palmeiras, Aguiar, and Frei Antônio were the electrical conductivity was above the limits of the current legislation in Brazil. The Frei Antônio presented the worst water quality with electrical conductivity and total dissolved solids higher than the current Brazilian legislation. It was concluded that physical-chemical analysis, together phytotoxicity of samples from stream water stopping using Lactuca sativa, was a valid indicator of environmental conditions and are useful tools to assess and compare the toxicity of stream surface water.