Potencial de aplicação da fibra Calotropis procera para a remoção de diesel em fase livre na água subterrânea

Abstract

Contamination of groundwater by petroleum-derived fuels, such as diesel, is a significant environmental problem, since its leakage/spilling can cause serious impacts on water and soil quality due to the transfer of contaminants such as benzene, toluene, ethylbenzene and xylenes, causing risk to public health and the ecosystem. Because of this, remediation methods for removing diesel from groundwater have been developed in order to delay and reduce environmental impacts. Among the techniques used, the application of biosorbent materials has gained prominence because, in addition to being biodegradable, they have high natural availability, low cost and good sorption capacity. Given this situation, this work aims to evaluate the sorption capacity of Calotropis procera (CP) fiber in natura for cleaning and removing diesel in groundwater in real samples contaminated with diesel. For this, the characterization of this biomaterial was carried out using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with field emission (FEG-SEM) and wettability and contact angle tests to investigate the properties hydrophobic and oleophilic. Furthermore, the sorption capacity of the CP fiber was evaluated through an experimental design varying the factors of diesel concentration and sorbent mass, obtaining a maximum capacity of 72.29±1.521 g.g-1 of fiber, with a concentration of 60 g. L -1 of diesel and 0,01 g of fiber. About the kinetic and isothermal studies, the diesel sorption mechanism by the fiber was better configured by the pseudo-second order kinetic model and by the Langmuir isothermal model. In addition, at the end of 8 reuse cycles, the fiber had a sorption capacity of 16.71 g.g-1 and a total cumulative capacity of 252.57 g.g-1 of diesel, attesting to its potential for reuse. The CP fiber showed to be a promising biosorbent in real environmental applications, removing from 98,55% to 99,97% of diesel with films varying from 0,25 cm to 1,5 cm in water, in a short time interval, demonstrating high performance free-phase diesel sorption in groundwater.