2 resultados para Environmental impacts
em Repositorio Institucional da UFLA (RIUFLA)
Resumo:
Landscape is dynamic, having complex nature, with tangible and intangible dimensions, presenting a continuous evolution process. The aim of this research were based on the identification and classification of landscapes in units and subunits, from the ownership by individuals; the development of a methodology to assist in the planning and management, conciliating conservation of natural areas with anthropic activities; and, from the information gathered, evaluate the different social groups aiming to design a landscape from the sustainable development perspective; thus better understanding both cultural and forest fragmentation processes, in the city of Ouro Preto, Minas Gerais. The research analyzed the current landscape and its historical evolution, distinguishing between material and immaterial dimensions. Information was raised from field trips, soil types, relief, slope, drainage, conservation units, administrative zoning, urban areas, natural resources, economy, tax raising, transport and building infrastructure, satellite images, types of management applied to the preservation or conservation of forests and fields, and semi-structured interviews with the various actors that modify and transform the territory, thus making a balance between the built landscape and the demands of the society and ecosystems. Results were composed by a map of land use in 2011; a map of landscape units and their subunits, with their appropriate definitions; a map with five levels of activities intensity, with their respective descriptions; and raising barriers to improving the welfare of the actors and the integrity of ecosystems. The number of generated ecosystem services are difficult to measure, but its benefits are useful for everyone. The physical changes are a reflection of the economy, which caused environmental impacts, mainly related to mining activities, tourism, agriculture and conservation of natural areas, all requiring ideally a shared management. In this sense, the landscape needs a management to create sustainable alternatives to anthropic activities. The dynamics of the landscape has been shaped by a slow evolution, set by mining activities due to the high financial revenues, there were areas of revegetation after clearcuts in the past, and now tourism lacks structure. The city has great potential for development projects with payments for environmental services, however, gaps for shared management exists.
Resumo:
A simple procedure for recovering potassium dichromate (K2Cr2O7 ) from treatment of residual sulphochromic solution was proposed in the present work by means of cooling crystallization. The decrease of temperature favored the crystallization of K2Cr2O7 due to the decrease of solubility. 5.0 L of sulphochromic wastes containing 48.08 g L-1 of Cr(VI) were treated and the process of crystallization was performed in three steps until crystals were not formed anymore. On each step the content of Crtotal was determined by flame atomic absorption spectrometry and Cr(VI) by colorimetric method with 1,5- diphenylcarbazide, resulting in the removal of 91% and 92% of Crtotal and Cr(VI), respectively. After the last step, the remaining Cr(VI) in the solution was reduced to Cr(III) from the addition of NaHSO3 , recovering via precipitation in pH 8 approximately 36.13 g of Cr(OH)3 . The final supernatant was discarded since chromium content was below the maximum limit established by the Brazilian legislation for effluents discharge, which corresponds to 0.10 and 1.0 mg L-1 of Cr(VI) and Cr(III), respectively. 628.4 g of K2Cr2O7 were recovered and the salt was characterized by X-ray diffraction and differential thermal analysis. Its applicability was compared to the standard K2Cr2O7 when determining the soil organic matter, in which there was no significant difference, thus inferring that the recovered compound may be incorporated on routine analyses. This recovering process allowed the reuse of K2Cr2O7 , thus reducing costs with the acquisition of new reagents and environmental impacts caused by the inadequate discard of sulphochromic solutions.