Remoção dos pertubadores endócrinos 17b-estradiol e p-nonilfenol por diferentes tipos de carvão ativado em pó(CAP) produzidos no Brasil : avaliação em escala de bancada / Removal of the endocrine disruptors 17b-estradiol and pnonylphenol by different powdered activated carbons (pac) produced in Brazil evaluation in bench scale

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

In the last decades, a growing scientific concern and public debate have been raised over the potential adverse effects associates to human and animal exposure to endocrine disruptors (EDs). Domestic sewers and treated effluents are the most common source of contamination and, according to the literature, these substances are only partially removed by conventional water and wastewater treatments. Adsorption on activated carbon has been recognized as an option for the removal of endocrine disruptors. However, the activated carbon efficiency, in general, depends on the original material, on the superficial area and pores size distribution and on the characteristics of the compound to be adsorbed. This work presents an evaluation of the removal of endocrine disruptors by powdered activated carbon (PAC), carried out under controlled laboratory conditions. The endocrine disruptors selected to be evaluated were the 17b-estradiol and the p-nonilfenol due to, respectively, the higher risk potential to live beings and the high concentrations found in sewerage and raw water. Adsorptive capacity experiments were carried out using samples prepared with ultra-pure water (around 1 μg/L de 17b-estradiol e 100 μg/L de p-nonilfenol) and PACs produced in Brazil (3 of vegetal origin and 1 of animal origin). Immunoassay (ELISA) was used to quantify ED residuals. It was verified that the Freundlichs Model was more adequate to describe the adsorption of 17b-estradiol on PAC of vegetal origin. The residuals curves obtained followed, approximately, a negative exponential decline with the increase of PAC dosage, presenting more significant removals for dosages below 10mg of PAC/L. It was observed, from correlations data, that the 17-estradiol had higher tendency to be adsorbed by micropores and that the animal origin PAC had a singular behavior. Although it presented the highest removal efficiency, the adsorption results were not adjustable to either Freundlichs or Langmuirs Models. Due to experimental problems, pnonylphenol adsorption capacity data are not presented, nevertheless the difficulties faced are discussed in details.

ASSUNTO(S)

p-nonilfenol. adsorção em carvão ativado engenharia civil perturbadores endócrinos endocrine disruptors 17b-estradiol activated carbon adsorption, 17b-estradiol, pnonylphenol.

ACESSO AO ARTIGO

Documentos Relacionados