ABSTRACT: Although Brazil is one of the world's leading exporter of agricultural products, the country is highly dependent on the importation of potassic fertilizers. K-bearing silicate rocks are reported as potential solutions to reduce external K dependency. This work evaluated K extraction from silicate Verdete rock, a glauconite-bearing rock containing 10 % of K2O, by solubilization with organic acids. Firstly, Verdete rock was reacted during 3-120 h with solutions of citric or oxalic acid at 2 % (m/v) in Erlenmeyer flasks by shaking. Oxalic acid extracted 6.5 % of K in Verdete, while citric acid extracted 2.3 %. Another experiment was performed to evaluate the effect of various oxalic acid concentrations (2, 4, 6, 8, and 10 %) and differing reaction times (12, 24, 48, and 72 h) on K extraction from Verdete rock. Soluble K concentration nearly doubled with the increase of reaction time from 12 to 72 h, rising from 20 to 37 mg L–1. Increments in K extraction were obtained by increasing oxalic acid concentrations up to 6 % and above this concentration, no significant gain was observed. The X-ray diffraction data showed that K extraction resulted from the formation of oxalate-metal complexes with metals in Verdete rock.

Resumo Como produzir modos e formas de coexistência que suscitem transformações subjetivas nas pessoas, contribuindo ao mesmo tempo para qualificar o seu relacionamento com os outros e com o meio ambiente, problematizando a institucionalização da vida humana no mundo contemporâneo? Eis a questão motriz da pesquisa proposta. A hipótese ora apresentada encaminha-se no sentido de que isso pode acontecer através da realização de microintervenções pedagógico-ambientais, tendo seu principal foco nos processos grupais e na análise da implicação do pesquisador com o processo de pesquisa. Trata-se de uma pesquisa-intervenção fundada no campo epistemológico da análise institucional, especificamente no método cartográfico e na ecosofia de Félix Guattari. Esta concepção de educação ambiental destaca a relevância dos três registros ético-estéticos – as ecologias ambiental, mental e social –, e fornece os aportes teóricos necessários para analisarmos a capacidade de reinvenção de si e do ambiente na perspectiva do processo de formação em educação ambiental. O dispositivo grupal buscou intensificar as transversalidades, as capacidades emocionais, inventivas, afetivas, imaginativas e intuitivas do humano, privilegiando a participação e o aprendizado coletivo, a autonomia, a solidariedade e os processos autogestivos. As atividades realizadas apresentaram-se como alternativas possíveis para desenvolver tais capacidades, colocando em movimento forças instituintes nos processos grupais, promovendo a ação-reflexão e o cuidado de si, do outro e do ambiente.

Abstract How does one go about designing modes and forms of coexistence that will induce subjec-tive changes in people, contributing at the same time to better their relationships with oth-ers and with the environment, examining the institutionalization of human life in the con-temporary world? This is the driving question of the present research work. The hypothe-sis presented is that this can happen through environmental-pedagogic micro-interventions with their main focus on group processes and an analysis of the role of the researcher in the research process. Ours is a research-work/intervention based on the epis-temology of institutional analysis, more especifically on the ecosophy and cartographic method of Félix Guattari. This design of environmental education highlights the relevance of three ethical-aesthetic registers – the social, mental, and environmental ecologies – and provides the theoretical support needed to our analyzing the ability one has to re-invent oneself and the environment from the perspective of an environmental-education process. The group device aimed at intensifying the transversalities and the emotional, inventive, affective, imaginative and intuitive human capacities, favoring collective learning and participation, as well as autonomy, solidarity and self-managing processes. The activities carried out were presented as possible alternatives to develop such capacities by putting into motion instituent forces within the group processes, as well as encouraging action-reflection and caring for oneself, others and the environment.