Mercury in waste in the European Union : sources, disposal methods and risks

http://www.elsevier.com/locate/issn/09213449Over the recent decades, there has been widespread concern regarding the toxic impact of mercury (Hg) in the ecosystem due to its mobility, volatility and potential for bioaccumulation. Hg in fish and the aquatic environment is also a great problem in the Nordic region of the EU1 (European Union). Hg is classified as a dangerous chemical in the countries of the EU. Hg in the regulation of waste is regarded as a dangerous substance which, when contained in waste, is one of the properties, leading to a classification of waste as hazardous. Estimation of the quantity of Hg in waste within the EU countries is an important task although still incomplete. In this present study, Hg in waste in the EU has been estimated at around 990 metric tonnes (t) (including coal combustion products, landfills, chlor-alkali waste and incinerator slag) for the year 1995, and it is suggested that if complete information was available for the 15 member states, the amount would be 2–4 times larger. During the 1990s there were 45 Hg cell chlorine facilities in the EU and the amount of Hg in chlorine (Cl2) was calculated at 95.2 t based on 14–17 gHg t−1 of Cl2 capacity. The waste from coal-fired power plants in the EU member states contained about 16.5 t of Hg, which was transferred to products for road construction, and other industrial uses or stored in landfills. This Hg can then be exchanged between the atmospheric, aquatic and terrestrial compartments. Hg is occasionally recovered from waste, but this is often discouraged for economic reasons. Recovery units are found, for example, in Germany, France, Austria, and Sweden. The total amount of secondary Hg recovered from waste is not known. Metallic Hg and Hg-bearing waste are exported and imported from the EU member states, except for export from Sweden, which is banned by national legislation. The use of Hg in lamps and batteries is declining, and the Nordic countries, Germany and Austria have stringent regulations on the use of amalgam and Hg thermometers. It is found that 18% of municipal solid waste generated in the EU is burnt in incinerators, in order to decrease the volume. 88 t of Hg enter into the landfills of the EU through waste and residues from waste incineration. Prevention of the generation of hazardous waste containing Hg is one of the most challenging tasks for the EU, with regard to sustainable waste management

Fósforo extraído pela solução de Mehlich-1 determinado por colorimetria e ICP em solos do Sul do Brasil Phosphorus extracted with Mehlich-1 determined by colorimetric and ICP methods in South Brazilian soils

A adoção do ICP para análise de fósforo tem apresentado controvérsias, pois o valor determinado por essa técnica, muitas vezes, não é comparável com o obtido por colorimetria. Nos EUA, alguns laboratórios apresentam restrições à adoção dessa técnica, pelas seguintes razões: as recomendações de adubação em uso foram desenvolvidas empregando-se o método colorimétrico para a determinação do P; e as diferenças significativas têm sido obtidas entre os teores determinados por colorimetria e por ICP, pois, devido à alta temperatura do plasma, o ICP mede outras formas de P além do ortofosfato, atribuída ao P orgânico na solução. Este estudo teve por objetivo comparar os teores de P extraído do solo pela solução de Mehlich-1, determinado por colorimetria (COL) e por ICP, em 595 amostras de solos do Estado do Rio Grande do Sul, com amplas variações nas características físicas, químicas e mineralógicas. Os teores de P extraído, determinado por ICP e por COL, não diferiram estatisticamente (r = 0,94; p < 0,001). Não foi observada diferença estatística entre os teores de P determinado pelas duas técnicas em solos com teores de P menores do que 30 mg dm-3. A diferença relativa (ICP/COL) não foi alterada pela textura, pelo teor de matéria orgânica, pelo pH e pelo índice SMP das amostras. As quantidades de P2O5 recomendadas para o milho tiveram alto grau de associação, e as doses não diferiram entre as técnicas de determinação. Com base nos resultados, pode-se concluir que a determinação do P disponível no solo, extraído pela solução de Mehlich-1, pode ser feita por ICP sem alterações nas tabelas de interpretação dos teores estabelecidos para o método colorimétrico, em solos do Estado do Rio Grande do Sul.<br>The adoption of ICP technique to determine P in soil testing has been questioned, due the values determined with this technique is not comparable that those determined with colorimetric method. In the USA, some laboratories are restricted to adopt the ICP technique due the follow reasons: the nutrient recommendations to plants were developed for colorimetric method for P determination; significantly differences have been obtained between P determined with colorimetric and ICP techniques, because the high plasma temperature can measure other P forms besides orthophosphate, attributed to organic P in solution. This study compared the P amounts extracted by Mehlich-1 solution and determined by COL and ICP techniques, in 595 soil samples from the state of Rio Grande do Sul (Brazil) with s wide range of soil physic, chemistry and mineralogic properties. The P amounts determined by ICP and COL did not differ statistically (r = 0.94; p < 0.001) in all soils and in the soils with P amounts > 30 mg dm-3. The relative difference (ICP/COL) was not affected by soil texture, pH, soil organic matter content, and potential acidity. The amounts of P2O5 recommendations to corn were similar, and not statistically different in both P determination methods. Based on the results, the available soil P extracted with Mehlich-1 solution can be determined with ICP technique being unnecessary modifications in the current P status interpretation table established for the colorimetric method for Southern Brazilian soils