Potencialidades do vermicomposto, de seu res?duo s?lido (da extra??o de subst?ncias h?micas), do biochar e de humina para o uso na remedia??o de solo contaminado com c?dmio

• Autor(a) principal: Pinto, Tatiana de Oliveira
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/1525
• topic: Heavy metal; retention; bioavailable; Metal pesado; reten??o; biodisponibiliza??o; Agronomia

Cadmium is a heavy metal and it offers high risks to human health and it can affect ecosystem functioning at trace levels due to high toxicity, persistence time, which transcends decades and the fact that its bioavailability not diminish the long term. Rice (Oryza sativa L.) has the ability to incorporate large amounts of Cd2+ in their tissues and, therefore, today is the cereal that further incorporates this metal in the human diet by ingestion, causing serious health problems like the known disease as "Itai-Itai", whose main symptoms severe pain in bones and frequent fractures. For this reason rice plants were used in this study in combination with natural materials to assess the effects of these Cd2+. Natural materials such derived from organic matter is currently being used in the remediation of soils and effluents, but studies on the risks of its use today are scarce and often controversial. The use of humified organic matter like vermicompost and its derivatives is a sustainable alternative for the remediation of soils and sewage contaminated by heavy metals due to their chemical composition environmentally non-aggressive, low production cost and possible application in various crops. The aim of this study was to investigate the characteristics of biochar, vermicompost (VC), its solid fraction (RVC) and humin for use in the remediation of soil contaminated with Cd2+. For this was performed characterization of the interactions between the metal and the material through Freundlich and Langmuir adsorption isotherms, spectroscopic techniques CP MAS 13C-NMR and FTIR was also evaluated the ability of each material to provide Cd2+ to plants rice, by determining the root and leaf development parameters and Cd2+ content in plant tissues and the substrate. The surface morphology of the materials was performed using scanning electron microscopy (SEM). This study demonstrates that biochar used and humin are not effective materials for use in remediation. The biochar, although showing a high retention of Cd2+ allowed the bio availability of Cd2+ increasing the accumulation in tissues of rice plants. VC and RVC resulted materials with high Cd2+ retention capacity with a low availability of the metal. Specifically, the RVC can be an effective material for remediation purposes. We warn the risks of use the materials studied for soil remediation purposes contaminated with Cd2+ and propose the use of a new natural source material for phytoremediation purposes.