Caracterización química y ecotoxicológica de metales pesados en sedimentos de las riveras del río Machángara, sector parque industrial

Abstract

The sediments are perhaps the most important components of aquatic ecosystems being the basis of biodiversity; but they can also act as a carrier and a source of contamination, such as heavy metals that are released into the water column due to changing conditions such as pH, redox potential, dissolved oxygen, etc. Therefore, the analysis of heavy metals in sediments to detect contamination that regularly escapes to a water analysis and provides information about critical areas of aquatic systems. Thus, this research assessed the quality of Machángara river sediments in the area of Industrial Park of Cuenca, through chemical analysis of heavy metals Pb, Cd and Zn in the bioavailable phase andecotoxicological tests. The biological effects were evaluated percentage dead organisms (Eiseniafoetida) and inhibition of seed germination and radicle elongation bioassays using a battery, in which the lethal dose fifty and fifty inhibitory concentration was determined, by Probit statistical analysis, the investigation concluded by estimating the ecological risk factor of sediments through the calculations of PEC and PNEC for each of the sampled sites. The sites were evaluated beginning, middle and end of the industrial park in the left margin, right and middle of the river; and statistical analysis using ANOVA was reached to establish whether there were significant differences between these places. The conclusive results of this research were: sediment quality in the nine sites evaluated were considered "" dangerous for the environment "" means that are harmful to all aquatic organisms. All sediments had environmental risk, however this factor is intensified in some place more than others, like the end of the industrial park and the range in which they are settled in the industrial park, which are the sites of major environmental risk.