Incorporação de tecidos vegetais contaminados por cromo em blocos cerâmicos

Abstract

Due to the generation of effluents from the industrial sector, in particular those with the presence of heavy metals, is necessary producing studies that act on the problem. One idea is currently developed phytoremediation, which involves the use of plants capable of absorbing pollutants and accumulate them in their tissues. However, it appears that after application of the technique is required to proper disposal of contaminated plant material. Thus, the study examined the bioaccumulation of III chromium by individuals Pontederia parviflora Alexander and Typha domingensis Pers and evaluated the incorporation of contaminated biomass in ceramic blocks. Therefore, it was tested the absorption efficiency of two plant species submitted the chromium concentration of 70,61 mg/L. Soon after, specimens without addition of biomass and incorporation of 5% and 10% contaminated biomass (in air and root portions separately) were prepared . The removal of chromium in wetland systems with P. parviflora was 47,75%, while in agricultural systems with T. domingensis reached 95.5%. The experimental results of some parameters such as linear shrinkage, linear shrinkage after firing and loss on ignition, meet the criteria established by NBR 7170/1983 for all bodies of evidence tested. Regarding the compressive strength it appears that the witness and the bodies of synthesized test with T. domingensis fall class A resistivity, while the others are in disagreement with the method recommended by the literature. It is further suggested to make further tests of resistance to the use of new clay, in order to obtain higher resistivity for specimens tested. As for water absorption, only specimens synthesized with 10 % biomass do not meet the standards set by NBR 7171/1992. The parameters characterizing of the material as liquidity and plasticity to classify the soil as highly plastic clay silts. After leaching test is noted that the material exhibits low concentration of chromium in the leachate (concentration < 0.1 mg/Kg), being largely composed of solid particles adhered to the clay and biomass. In general, it is observed that the bodies fit in parameters tested and, therefore may be recommended as an alternative applicable for subsequent disposal of the tissues plant contaminated in Phytotreatement.