Zoneamento agroecológico do município de Lagoa Seca, PB.

Visa-se, cinzelar, neste estudo um zoneamento em que se considerem os aspectos agrícolas, ecológicos e sociais inerentes ao município de Lagoa Seca, PB, elaborado através da análise dos vários cenários apresentados na área. O uso de um conjunto de recursos, como fotointerpretação, processamento de imagens georreferenciadas, posicionamento por satélites, associados à teoria sistêmica de Bertrand, possibilitou a identificação, delimitação e análise das áreas de uso antrópico, agrícola e das áreas com remanescentes vegetais significativos, que caracterizam o município. Foram elaborados para a área em estudo, arquivos digitais georreferenciados, relativos aos temas: limite municipal, áreas urbanizadas, infra-estrutura viária, rede de drenagem, altimetria, cobertura vegetal natural, uso agrícola do solo e zoneamento. Os resultados obtidos evidenciaram que o município apresenta quatro regiões com aspectos distintos, as quais foram identificadas como regiões agroecológicas, de acordo com o fator que mais se destacou em cada área

Adaptation of biomixtures for carbofuran degradation in on-farm biopurification systems in tropical regions

A biomixture constitutes the active core of the on-farm biopurification systems, employed for the detoxification of pesticide-containing wastewaters. As biomixtures should be prepared considering the available local materials, the present work aimed to evaluate the performance of ten different biomixtures elaborated with by-products from local farming, in the degradation of the insecticide/nematicide carbofuran (CFN), in order to identify suitable autochthonous biomixtures to be used in the tropics. Five different lignocellulosic materials mixed with either compost or peat and soil were employed in the preparation of the biomixtures. The comprehensive evaluation of the biomixtures included removal of the parent compound, formation of transformation products, mineralization of radiolabeled CFN, and determination of the residual toxicity of the process. Detoxification capacity of the matrices was high, and compost-based biomixtures showed better performance than peat-based biomixtures. CFN removal over 98.5 % was achieved within 16 days (eight out of ten biomixtures), with half-lives below 5 days in most of the cases. 3-Hydroxycarbofuran and 3-ketocarbofuran were found as transformation products at very low concentrations suggesting their further degradation. Mineralization of CFN was also achieved after 64 days (2.9 to 15.1 %); several biomixtures presented higher mineralization than the soil itself. Acute toxicity determinations with Daphnia magna revealed a marked detoxification in the matrices at the end of the process; low residual toxicity was observed only in two of the peat-based biomixtures. Overall best efficiency was achieved with the biomixture composed of coconut fiber-compost-soil; however, results suggest that in the case of unavailability of coconut fiber, other biomixtures may be employed with similar performance.Universidad de Costa Rica/[802-B4-609]/UCR/Costa RicaUniversidad de Costa Rica/[802-B2-046]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones de Costa Rica/[FI-093-13]MICITT/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones de Costa Rica/[802-B4-503]MICITT/Costa RicaJoint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture/[TC COS5/029]IAEA/FAO/AustriaUniversidad de Costa Rica/[802-B4-609]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA

Alternative approaches to determine the efficiency of biomixtures used for pesticide degradation in biopurification systems

Biopurification systems were developed for the biological treatment of pesticide-containing wastewaters originated from agricultural production. They are aimed at reducing point-source contamination related to the inadequate handling of pesticides during filling and cleaning of spraying equipment or improper disposal of application residues. These systems contain a biomixture, which comprises their biologically active core where accelerated pesticide degradation takes place. It is a common practice to determine the efficiency of biomixtures by analytical approaches that are focused on the quantification of the pesticides and their subsequent dissipation in time. Nonetheless, the simple removal of original pesticide molecule does not necessarily indicate that the treatment process is ecologically friendly, due to the possible formation of transformation products of high toxicity that are difficult to identify and quantify. This chapter discusses alternative approaches to obtain a more complete scenario regarding biomixture efficiency. These approaches include the determination of the pesticide mineralization using radiolabeled pesticides and ecotoxicological assays to determine the detoxification degree achieved by the matrix. Similarly, as the useful life of biomixtures varies according to the materials employed in its production and the climatic conditions of every region, the authors also suggest a methodology to monitor the performance of biomixtures during their aging process.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro en Investigación en Contaminación Ambiental (CICA