Fluvial geochemistry applied to the rates of chemical weathering and soil removal in the Ribeirão do Cipó basin, Poços de Caldas (MG)
Description: Rain and river water present spatial and temporal variations in their composition, mainly due to geomorphology, geology, pedology, land use, in short, all the factors that determine the characteristics of a hydrographic basin. The Ribeirão do Cipó basin has an area of approximately 78 km² and is used to regulate flow for power generation, industrial, agro-industrial and tourism use, besides being an important source for drinking water supply. In the Ribeirão do Cipó watershed there is the Cipó dam, which forms a reservoir that stores approximately 32 million cubic meters of water, and is responsible for regulating the flow that feeds the turbines of the SHPC installed downstream. In addition, the hydrographic basin is also responsible for 47% of the public water supply in the municipality of Poços de Caldas-MG, thus being of high importance, due to the use of its springs, for two of the most relevant activities in the context of water resources, public supply and electricity generation, besides the use for agriculture and leisure. This basin is highly vulnerable to human interventions, especially those that accelerate the erosive processes, reducing the useful life of the reservoir and substantially increasing the cost of removing suspended solids when treating its waters for supply purposes. Furthermore, the relevance of the project stands out in at least three complementary aspects: Involvement of researchers from ICT/UNIFAL-MG, UFLA AND UNITINS with the development of technical competence of the group involved which is in the process of consolidation; generation of a set of technical-scientific information, which will subsidize not only the Municipal Departments of Electricity (DME) and Water and Sewage (DMAE), but also, the Basin Committee of the Mogi Guaçu and Pardo River tributaries, which develop their management actions in the study area.
Coordinator: Prof. Dr. Diego de Souza Sardinha
Period: 2019-2022.
Funding: Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Fapemig)
Environmental Monitoring
Integrity of the benthic macroinvertebrate community in the Ribeirão das Antas watershed (Poços de Caldas Plateau, MG)
Description: Aquatic ecosystems are a valuable natural resource. However, the development of societies has imposed an accelerated deterioration of these environments, causing changes in the biological community structure. Among the communities that inhabit aquatic ecosystems, benthic invertebrates are an important group because they participate in the process of nutrient cycling and energy transfer, as well as serving as excellent bioindicators. On the plateau of Poços de Caldas, between 1977 and 1995, uranium ore was mined at the Brazilian Nuclear Industry (UTM-Caldas). Currently, this mine is deactivated, but there is still the formation of acid mine drainage (AMD) through bacterial action on tailings and waste rocks resulting from ore extraction. This AMD after being treated with quicklime has been discharged into the Ribeirao das Antas, which supplies water to the city of Poços de Caldas. The objective of this project is to study the structure of the benthic invertebrate community of the Ribeirão das Antas watershed in order to verify possible impacts of AMD on this community, as well as to understand its role in the functioning of these ecosystems. Collections will be made in lotic and lentic ecosystems. Benthic fauna samples will be obtained using a Van Veen dredge for lentic environments and a D net or Surber net for lotic environments. The environmental characterization will be done through analysis of sediment samples (organic matter, particle size fractions and metals) and water (temperature, pH, electrical conductivity, dissolved oxygen concentration, chlorophyll, nitrogen compounds, phosphates and metals). It is hoped that the development of this project will increase knowledge of aquatic biodiversity in Brazil, especially in Minas Gerais, as well as contribute to the understanding of possible effects of MAD on the benthic fauna.
Coordinator: Prof. Dr. Paulo Augusto Zaitune Pamplin.
Period: 2012-2014.
Funding: Fundação de Amparo à Pesquisa do Estado de Minas Gerais (Fapemig).
Wastewater Treatment
Precipitation of metals from acid mine drainage by biologically generated sulfate
Description: One of the modifications resulting from mining activity is the introduction of water and oxygen into environments containing reduced minerals. These elements lead to the oxidation of these minerals, among which metal sulfides are included. This process results in the release of protons, sulfate ions, and metals into the aqueous medium. The increased acidity of the medium further results in the subsequent dissolution of heavy metals from oxides and carbonates. This aqueous medium of low pH and high metal and sulfate concentration is called acid mine drainage (AMD). The formation of acid mine drainage is a problem affecting many countries in the world, whose impacts include the reduction of species diversity and total biomass in contaminated water bodies, as well as reducing the possible uses of these water resources. Acidic waters resulting from active or abandoned mines are often rich in sulfuric acid and dissolved iron, and have a low pH (less than 4). These factors can compromise the aquatic life in the receiving bodies, as well as making it unfeasible to use this water for domestic or commercial supply. Thus, it is necessary to understand the alternatives for the treatment of this effluent, among them the biological treatment involving sulfate-reducing bacteria. Among the advantages of the biological process is the possibility of joint removal of sulfate, by increasing the pH, and of metals, by precipitation in the form of metallic sulfides from the biologically generated sulfide. This project aims to investigate the precipitation of metals Fe, Zn and Cu both in the liquid phase and in the biomass by sulfide generated in the biological processes of sulfate reduction from acid mine drainage, using sequential anaerobic batch reactors with respect to the influence of initial pH and metal concentration.
Coordinator: Profª. Dr.ª Renata Piacentini Rodriguez
Period: 2012-2014.
Funding: National Council for Scientific and Technological Development (CNPq).
Studies of Sulfate Reducing Bacteria (SRB) from anoxic Amazonian sediments involved in Mercury methylation
Description: The western Amazon region suffered an accelerated process of uncontrolled growth, irresponsibly encouraged by the federal government in the mid-1970s and 1980s. This “development” strategy proved inadequate and promoted innumerable negative consequences to the environment, such as urban and rural infrastructure problems. An important fact to consider when talking about environmental degradation in the Amazon region is the “gold rush”. Estimates indicate that in the 1970s, about 180,000 tons of gold were produced annually in the North region. In the last 20 years, gold mining in the northern region of Brazil may have released 3,000 tons of mercury into the environment. About 98% of the mercury in aquatic ecosystems is immobilized in the sediment. Under conditions of dredging and resuspension of sediment, mercury species can be transferred into the water column. Inorganic mercury (Hg 2+) is the most dominant form of non-volatile mercury in these environments and can be transformed under biotic and abiotic conditions into methyl mercury (CH3Hg+), a potent neurotoxic compound for humans. Sulfate Reducing Bacteria (SRB) are known as the most important mercury methylating microorganisms in anoxic environments. When it comes to studies involving the metabolic pathway involved in the process, few published scientific works reveal the lack of knowledge in this area. Despite the works mentioned, the mechanism used by BRS in the methylation process is still to be understood. In the present proposal, we intend to study the BRS groups from Amazonian sediment samples involved in the methylation of Mercury. For this, sediment samples will be collected from Lake Puruzinho, Amazonas State, Brazil. The sediment will be used as inoculum in the enrichment assays of sulfate reducing bacteria. The quantification of the BRS will be done by the MPN method. After BRS enrichment, mercury methylation assays will be performed. At the end of the process techniques for isolation of the BRS involved in the mercury methylation process will be adopted. The isolated microorganisms will be identified by sequencing fragments of the 16S DNAr. These assays aim to obtain a greater knowledge about the microbial community present in Amazonian sediments involved in Hg cycling, but specifically in the important process of methylation of mercury and consequently assist in projects for the recovery of areas contaminated by this metal.
Coordinator: Prof. Dr. Gunther Brucha.
Period: 2012-2014.
Funding: Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).