Contribuição à gestão de resíduos sólidos e substâncias tóxicas persistentes nas cidades de Maputo e Matola

Abstract

This degree work aims to produce a practical guide that serves national working groups with regard to procedures related to the collection, compilation and evaluation of data and relevant information on sources, quantities and qualities, levels of concentration in the environment , risks and forms of disposal of solid waste and persistent toxic substances of agricultural and industrial origin. The correct management of urban solid waste, industrial waste and persistent toxic substances requires the support of a database developed according to internationally accepted criteria in order to ensure comparability of data and avoid duplication. This database is implemented in the form of a local survey where the most relevant information is collected, namely the quantities and characteristics of waste and PTS. For the proper management of the problem of solid waste in the cities of Maputo and Matola, it is essential to have a thorough knowledge of the quantities and characteristics of the waste produced there. This is important because any future project for the collection and disposal of this waste will always have to be dimensioned based on the total quantities to be processed and also because the chosen system must take into account the qualitative characteristics of this waste. Particularly the method of disposal to be applied, whether by incineration, composting or landfill, always depends on the chemical and physical characteristics of the waste to be treated. The selection of transport equipment, the choice of circulation routes, the choice of compaction equipment (bulldozers) and auxiliary equipment and the entire study of the system's economy can only be done on the basis of concrete data. In the case of Maputo and Matola there are no statistical studies on solid waste that are sufficiently reliable to support the entire project of planning and designing an integrated collection and processing system. Such studies are quite expensive and difficult to carry out due to the heterogeneity of waste produced either by domestic and commercial activity or by industrial activity, so their execution must be carried out within the scope of a project with central coordination ie under the supervision of MICOA and direct participation of the National Institute of Statistics. Part of this fund can be recovered by implementing a waste sorting and separation system and using modern technologies for recycling and treatment by composting and later selling it in the form of manure, as is usually the case around big cities in other countries. The other part can be achieved through the municipal fees and fines collection system. Taking into account the meteorological conditions, and the quality of the soils, the low levels of precipitation, and the low population density, the region of Macandezulo-Mapai, in the province of Gaza potentially represents an area capable of installing the necessary landfill for the waste. high toxicity industrials. However, the possible existence of incompatibility with projects of a cross-border tourist nature must be taken into account before making a final decision. Any of the proposed sanitary landfills should be permanently controlled via water quality verification using the most sophisticated analytical techniques as a means of preventing contamination of groundwater. (TRADUÇÃO NOSSA)