ABSTRACT One of the most prominent fields of environmental chemistry is the study and the removal of micro-pollutants from aqueous matrices. Analytical techniques for their identification and quantification are becoming more sensitive and comprehensive and, as a result, an increasing number of drugs have been detected in environmental samples. However, the literature shows that conventional treatments for drinking water and wastewater are not sufficient for remove these compounds. This study aims to check whether the process of hydrothermal carbonization (CHT) is effective in removing the synthetic sex hormones: ethinyl estradiol, gestodene and cyproterone acetate from aqueous samples. The system used in CHT basically consists of a pressurized reactor made of stainless steel and solutions of compounds of interest, both individual and mixed, with a concentration of 1.0 μg.L-1 and a pH range of 2.0 to 3.0. The maximum surface temperature in the reactor was about 180 °C, the internal pressure was 20 bar with 90 minutes for the reaction. Four experiments were conducted, one for each hormone and one with the three hormones together. In individual tests removal of the compounds was found to be 99.8% for ethinyl estradiol, 99.3% for gestodene and 100% for cyproterone acetate. For a mixture of the hormones treated under the same conditions, the mean values of CHT-removal of Ethinylestradiol, Gestodene and Cyproterone Acetate were 99.60%, 96.80% and 68.90%, respectively. The impact of the matrix effect may have affected the efficiency of the hormone removal process by CHT.
Titanium was examined in different black tourmalines by spectrophotometric analyses in the region between 12500 and 27000 cm-1 (800-370 nm) using a microscope spectrophotometer MPV-5P, Leitz (Germany), and chemically analyzed on an electron microprobe Camebax Microbeam, Cameca (France) in WDS Mode. Fourteen tourmaline samples with their face oriented parallel to the principal axis, cut and polished down to thin sections, showed polarized spectra of two broad absorption bands at approximately 14000 cm-1 (715 nm) and 24000 cm-1 (417 nm). Precision thickness measurements were used to calculate the absorption coefficients α. For the absorption around 24000 cm-1, a linear correlation was observed between α and the TiO2 content (mass %). Another linear regression was observed between α and the product of TiO2 and FeO (%) contents. Cations located in the Y- and Z-octahedrons of the structure that are connected over edges might contribute to intervalence charge transfer transitions (IVCT) between Ti3+-Ti4+, Fe2+-Ti4+ and Ti3+-Ti4+-Fe3+.
Titânio em turmalinas pretas foi analisado por espectrofotometria entre 12500 e 27000 cm-1 (800-370 nm) em um microscópio MPV-5P, Leitz (Alemanha), e analisado quimicamente em uma micro-sonda eletrônica Camebax Microbeam, Cameca (France) (WDS-mode). Quatorze turmalinas orientadas com faces paralelas ao eixo trigonal, cortadas e polidas até espessuras finas mostraram, em espectros polarizados, duas bandas largas de absorbância a aproximadamente 14000 cm-1 (715 nm) e 24000 cm-1 (417 nm). Medidas de espessura das amostras foram usadas no cálculo de coeficientes de absorção α (cm-1). Para a banda em torno de 24000 cm-1 (417 nm), foi observada uma correlação linear entre α e a concentração em massa de TiO2 (%). Outra regressão foi observada entre α e o produto da concentração em massa de TiO2 (%) e FeO (%). Cátions localizados em grupos de octaedros Y e Z conectados através dos seus lados podem contribuir para as transferências de carga Ti3+-Ti4+, Fe2+-Ti4+, Ti3+-Ti4+-Fe3+.