DegradaÃÃo anaerÃbica de BTEX em reatores alimentados com Ãgua contaminada por gasolina

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The underground water quality has been damaged because of storage tank spills from gas stations. The most common organic pollutants are the BTEX compounds (benzene, toluene, ethylbenzene, and xylenes) as a consequence of their toxicity, carcinogenicity and teratogenicity. The use of anaerobic bioreactors is an alternative for the bioremediation of water contaminated with these compounds. In this work, the anaerobic biodegradability of BTEX as evaluated for the treatment of synthetic wastewater that simulated water contaminated with gasoline, considering the influence of macro and micronutrients. Three reactors were essayed (RI, RII and RIII) with 4 l each one. They were operated with bath cycles of 48 hours, with constant agitation and maintained in a 30 degree temperature room. The inoculum used were a mix of sludge from UASB reactors (domestic wastewater: slaughterhouse wastewater, 1:1). The experiments were conduced in four phases with progressive increments of COD, in mg.l-1, (FI-1000, FII-1000, FIII-2000 and FIV-4000). In the first phase (FI) domestic wastewater was used to promote the adaptation of the inoculum in all reactors. From phase II (FII) to phase four (FIV), the reactors were fed with: RI - ethanol, macro and micronutrients; RII â water contaminated with gasoline and macronutrients; RIII - water contaminated with gasoline, macro and micronutrients. The results showed that the presence of micronutrients was determinant of the best performance of COD removal observed in RIII (56%, 88% and 83% to FII, FIII and FIV) as compared with the reactor RII (55%, 32% and 42% to FII, FIII and FIV). However, it was not observed influence of micronutrients on the BTEX removal. Also, the presence of BTEX do not affected the performance of COD removal in RIII since its performance was similar to RI. In the last phase (FIV), the biggest COD rate removal was obtained in the first 12 hours of experiment for all reactors essayed. Therefore, the choice of the treatment should consider the compound of interest, because it can be convenient to invest on the addition of micronutrients for the removal of total organic matter, while removal, these nutrients do not have interference for the BTEX removal

ASSUNTO(S)

etanol macro e micronutrientes btex macro and micronutrients gasolina ethanol degradation anaerobic gasoline btex degradaÃÃo anaerÃbia engenharia civil

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