CONCENTRATION OF SUSPENDED SOLIDS BY SPECTROPHOTOMETRY

Abstract

The use of sensors with optical principles designed to estimate sediment transport, and mainly the concentration of suspended solids (CSS) constitutes a robust technique that is currently consolidated and well disseminated in the scientific community, thus configuring an important tool in research, management and control of river basins. The present study, carried out in a water body located near the mouth of the Coxim River - (Coxim, MS), consisted of comparing Nephelometric Techniques and the integrated area of ​​absorbance at wavelengths in the spectrum from 400 to 600 mm (A400-600) and these are measured using a UV/VIS spectrophotometer for indirect determination of CSS. This water body showed characteristics of high sediment input; and for the purpose of possible relationships between the parameters and the characterization of suspended sediments transported by the river, the granulometry (Medium Sand, Fine Sand, Silt and Clay) of the processed samples was determined. The interactions between the parameters to indirectly determine CSS showed the following correlations: (p<0.001); Nephelometric with (R=0.942) and A400-600 (R=0.959); and the particle size fractions, in turn, indicated: (%) of Silt (52.6 ± 17.4), in addition to values ​​close to the distribution of Clay (15.3 ± 6.73), Fine Sand (15.6 ± 10.83) and Medium Sand (16.7 ± 11.84). In this context, according to the results of the residues and correlations, it was observed that A400-600 behaved in a more allusive way compared to the Nephelometric technique in drought and flood events, thus estimating the Detection Limit for CSS (26 .47 mg.L^-1 and 44.67 mg.L^-1) respectively.