Aplicação de macrófitas como biossorventes no tratamento de rejeitos radioativos líquidos

Abstract

Radioactive waste as any other type of waste should be treated and disposed adequately. It is necessary to consider its physical, chemical and radiological characteristics for choosing the appropriate action for the treatment and final disposal. Many treatment techniques currently used are economically costly, often invalidating its use and favoring the study of other treatment techniques. One of these techniques is biosorption, which demonstrates high potential when applied to radioactive waste. This technology uses materials of biological origin for removing metals. Among potencial biosorbents found, macrophytes acquatics are useful because they may remove uranium present in the liquid radioactive waste at low cost. This study aims to evaluate the biosorption capacity of macrophyte acquatics Pistia stratiotes, Limnobium laevigatum, Lemna sp and Azolla sp in the treatment of liquid radioactive waste. This study was divided into two stages, the first one is characterization and preparation of biosorption and the other is tests, carried out with uranium solutions and real samples. The biomass was tested in its raw form and biosorption assays were performed in polypropylene vials containing 10 ml of solution of uranium or 10ml of radioactive waste and 0.20g of biomass. The behavior of biomass was evaluated by sorption kinetics and isotherm models. The highest sorption capacities found was 162.1 mg / g for the macrophyte Lemna sp and 161.8 mg / g for the Azolla sp. The equilibrium times obtained were 1 hour for Lemna sp, and 30 minutes for Azolla sp. With the real waste, the macrophyte Azolla sp presented a sorption capacity of 2.6 mg / g. These results suggest that Azolla sp has a larger capacity of biosorption, therefore it is more suitable for more detailed studies of treatment of liquid radioactive waste. .

Estudo de bioacumulação de metais tóxicos e elementos traço em amostras de macrófitas aquáticas flutuantes do Reservatório Guarapiranga, São Paulo - SP, Brasil

“…Resultados das concentrações de metais e metaloides em amostras Hg P-01 0,1 0,11 < 0,10 -0,13 < 0,10 --0,17 0,49 0,14 nd 0,31 P-02 0,11 0,13 < 0,10 -0,16 < 0,10 --P-03 < 0,10 --0,13 0,13 < 0,10 -0,21 (GALAL, FARAHAT, 2015;GONÇALVES JÚNIOR, 2008;HENARES, 2008;KASSAYE, et al, 2016;MAINE, DUARTE, SUÑE, 2001;LAGGER, 2004;MARTIN, 2008;OGUNKUNLE et al, 2015;SKINNER, WRIGHT, PORTER-GOFF, 2007;SOARES et al, 2008;SUÑE et al, 2007;VALITUTO et al, 2006;VIEIRA, 2016 Tabela 5.14 -Cargas fatorais das três Componentes Principais extraídas pela AFE (Campanha 1 -chuvosa). As medianas das concentrações de As nas amostras de macrófitas e sedimentos da primeira campanha de coleta foram iguais a 1,78 mg kg -1 (macrófitas) e 10,3 mg kg -1 (sedimentos), enquanto que as respectivas médias foram 2,11 mg kg -1 e 8,34 mg kg -1 .…”