The growth in both population and its consumption have boosted the quantity of solid waste generated and consequently the problems of its proper management. Selective collection and recycling programmes promote the reduction of the amount of waste directed to landfills, reducing their environmental impacts and increasing their lifespan. Through selective collection, the recyclable solid waste (RSW) can be directed to co-operatives of waste pickers who carry out sorting and, sometimes, can beneficiate these materials, generating employment and income for the waste pickers, promoting their social inclusion and better working conditions. This research identifies and quantifies the different materials from RSW collected and marketed by a waste pickers’ association in the municipality of Belém. Furthermore, it performs an economic evaluation of the activity, through monitoring and data collection from all steps of the recyclable waste management process (collection, transportation and marketing/disposal) by the waste pickers of the association from mid-/late October to mid-December 2016, comparing with the data obtained for 1 year by members notes and the association incomes. The results show that paper, paperboard and plastic are the main materials collected and marketed by the association and those that create higher income.

This article aims to analyze and characterize the problem of anthropic interventions along the Tucunduba stream, located in the city of Belém-PA, aiming to show how the process of urban expansion interferes with the water body, as well as the consequence of the disordered occupation in the margins of the igarapé. Since it causes soil changes and increased runoff, which is responsible for transporting organic and inorganic materials to the river, it significantly increases its pollutant load, causing flooding, river eutrophication, and other problems of water degradation. The bibliographic review and the on-site visit, as well as photographic record and georeferenced images made available in Google Earth, were used for the basement of the same, observing the general condition of the area, to characterize the anthropic factors that contribute to the degradation of the Igarapé.

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Resumo. Códigos esféricos n-dimensionais gerados por grupos comutativos em dimensão par, n = 2m, podem ser determinados pelo quociente de reticulados m-dimensionais, quando os vetores que geram o sub-reticulado são mutuamente ortogonais [4]. Apresentamos a construção de sub-reticulados nestas condições, a partir do reticulado hexagonal, A2. Comparamos a distância mínima do código esfé-rico construído através do quociente destes reticulados com o limitante da distância mínima estabelecido em [5].Palavras-chave. Reticulados, códigos esféricos, distância mínima.