Determination of the Ca, Mn, Mg and Fe in honey from multiple species of stingless bee produced in Brazil.

Stingless Bees (SB) honey is a product used for different purposes, and it is worth highlighting the presence of metallic species, which can have a nutritional or toxic effect, depending on the metal present and/or the amount ingested. Therefore, the objective of this work was to quickly determine Fe, Mn, Mg and Ca in SB honey, using slurry sampling and FAAS of 88 honey samples from different regions of Brazil. The concentrations varied from < LOD to 364 µg g (Ca).

Adsorption of naturals hormones estrone, 17-estradiol, and estriol by rice husk: monocomponent and multicomponent kinetics and equilibrium.

In the present study, the use of the rice husk biomass as an alternative biosorbent for treating the estrone, 17 -estradiol, and estriol hormones in monocomponent and multicomponent systems was investigated. The high-performance liquid chromatography technique (HPLC-UV) was applied in order to quantify the hormones, validating this method according to ANVISA and INMETRO. The biosorbent presented functional groups typical of cellulose, hemicellulose, lignin, and proteins, with an amorphous, fibrous, and porous surface.

Identification of organic compounds in landfill leachate treated by advanced oxidation processes.

Landfill leachates are considered to be complex effluents of a variable composition containing many biorecalcitrant and highly toxic compounds. Considering the shortage of studies concerning the treatment of landfill leachates using ozone, as well as its combination with catalysts, the aim of this paper was to identify the organic compounds in this effluent treated with advanced oxidation processes (AOPs) of ozonation (O), and heterogeneous catalytic ozonation with TiO (O/TiO) and with ZnO (O/ZnO). In addition, this study sought to assess the efficiency of the removal of the organic matter present in the leachate.

Removal of diclofenac by conventional drinking water treatment processes and granular activated carbon filtration.

This study was carried out to evaluate the efficiency of conventional drinking water treatment processes with and without pre-oxidation with chlorine and chlorine dioxide and the use of granular activated carbon (GAC) filtration for the removal of diclofenac (DCF). Water treatment was performed using the Jar test with filters on a lab scale, employing nonchlorinated artesian well water prepared with aquatic humic substances to yield 20HU true color, kaolin turbidity of 70 NTU and 1mgL(-1) DCF. For the quantification of DCF in water samples, solid phase extraction and HPLC-DAD methods were developed and validated.

Influence of the apparent molecular size of aquatic humic substances on colour removal by coagulation and filtration.

This study aims to verify the influence of the apparent molecular size of aquatic humic substances (AHSs) on the effectiveness of coagulation with aluminium sulphate and ferric chloride. Coagulation-filtration tests using the jar test and bench-scale sand filters were carried out with water samples having a true colour of approximately 100 Hazen units and prepared with AHSs of different molecular sizes. Stability diagrams are presented showing regions of > or = 90% and > or = 95% apparent colour removal delineated for each water sample using plots of total metal ion concentration (Al3+ and Fe3+) versus coagulation pH.