ABSTRACT
The rupture of the Fundão mine dam in Mariana municipality, Minas Gerais State, Brazil, spilled the tailings across the Doce River basin. These tailings, composed of residues discarded from the beneficiation of iron ore, are rich in SiO and AlO, as well as some ether amine compounds and NaOH. The aim of this study was to assess the distribution of these sediments, as well as their effect on the riparian zones reached, as compared with preserved sites. Sediment deposition in the river resulted in a morphological change from a meandering profile to a braided aspect. The nutrient and mineral content (P, K, Ca, Mg, Cu, Fe, Mn, Zn, and NO) and soil organic matter of the sediments were depleted, whereas NH, Na, and pH increased. A random presence of ether amines in the sediments was confirmed by quantitative and chromatographic analyses, with concentrations ranging from 0 to 57.8 mg kg; Na reached values as high as 150 mg kg. The impact of the dam tailings on biota was assessed by estimating total microbial biomass (phospholipid fatty acids), which were depleted in sediments relative to soils from preserved sites. Overall plant mortality, as well as a low resilience capacity, were also observed. Ether amines and Na present in the sediments had a strong toxic effect in the environment. Identification of these substances as the main impact factors will help guide future remediation efforts.
Subject(s)
Chemical Hazard Release , Environmental Restoration and Remediation/methods , Industrial Waste , Mining , Brazil , Risk Assessment , Rivers/chemistry , Soil/chemistrySubject(s)
Cutis Laxa/congenital , Cutis Laxa/genetics , Genes, Recessive , Mutation , Pyrroline Carboxylate Reductases/genetics , Abnormalities, Multiple/diagnosis , Abnormalities, Multiple/genetics , Child, Preschool , Cutis Laxa/diagnosis , Female , Humans , Infant , Infant, Newborn , Male , Pedigree , Phenotype , delta-1-Pyrroline-5-Carboxylate ReductaseABSTRACT
Nowadays, stormwater infiltration systems are frequently used because of their ability to reduce flows and volumes in downstream sewers, decrease overflows in surface waters and make it possible to recharge groundwater. Moreover, they come in various forms with different uses. Despite these advantages the long term sustainability of these systems is questionable and their real performances have to be assessed taking into account various and sometimes conflicting aspects. To address this problem a decision support system is proposed. It is based on a multicriteria method built to help managers to evaluate the performance of an existing infiltration system at different stages of its lifespan and identify whether it performs correctly or not, according to environmental, socio-economic, technical and sanitary aspects. The paper presents successively: the performance indicators and the way they were built, the multicriteria method to identify if the system works properly and a case study.
Subject(s)
Conservation of Natural Resources , Decision Support Techniques , Drainage, Sanitary/standards , Filtration/standards , Floods , Models, Theoretical , Drainage, Sanitary/economics , Drainage, Sanitary/methods , Filtration/economics , Filtration/methods , France , Time Factors , Urbanization , Water MovementsABSTRACT
Tritium content in the leachate of sanitary landfills, in concentrations well above those observed in global precipitation, can be used as a tracer for the evaluation of the contamination of groundwater in piezometers of the landfills and in neighbouring tubular wells. This possibility was first investigated in Brazil for sanitary landfills in the region of Belo Horizonte City. Tritium levels together with the content of metals present in water and the measurement of soil electrical conductivity, proved to be valuable for these studies and also as a tracer for hydrodynamic studies of the surface water in the Ressaca creek.
Subject(s)
Refuse Disposal , Tritium/analysis , Water Pollution, Chemical/analysis , Water Supply/analysis , Brazil , Geography , Water Pollutants, Chemical/analysisABSTRACT
The objective of the present work is to compare two methodologies based on multicriteria analysis for the evaluation of stormwater systems. The first methodology was developed in Brazil and is based on performance-cost analysis, the second one is ELECTRE III. Both methodologies were applied to a case study. Sensitivity and robustness analyses were then carried out. These analyses demonstrate that both methodologies have equivalent results, and present low sensitivity and high robustness. These results prove that the Brazilian methodology is consistent and can be used safely in order to select a good solution or a small set of good solutions that could be compared with more detailed methods afterwards.