Determinação de Cd e Pb: avaliação de sedimentos do Rio Jundiaí - SP e Ribeirão Piraí - SP e lodo proveniente de uma estação de tratamento de esgotos

Abstract

Jundiaí river is the main stream in the Jundiaí Hydrographic Basin and its water is not considered safe for public supply. The water problem is getting worse with the development of the region. The Pirai stream, have been one of the last potable water resource. With the purpose of investigating the sediment quality, due to its influence on the water quality, bioavailable and total Cd and Pb were determined using TS-FF-AAS. Total Cd and Pb up to 2.47 and 24.7 µg g-1 were measured, respectively. The wastewater sludge showed concentrations of 4.01 and 171 µg g-1 , for the same metals.

Development of a carbon nanotubes paste electrode modified with crosslinked chitosan for cadmium(II) and mercury(II) determination

“…A sample mass of 100 mg was digested with 2.0 mL of aqua regia and 1 mL of concentrated H 2 O 2 , in a closed microwave oven for 34 min. After cooling the microwave vessels, 1.0 mL of 1.0 mol L À1 HF was added for the attack of the silicate fractions and 0.5 g H 3 BO 3 for the complexation reaction of the remaining fluorides [47]. Finally, the sediments samples A (1.37 Â 10 À5 mol L À1 ), B (1.47 Â 10 À5 mol L À1 ), C (1.48 Â 10 À5 mol L À1 ) and D (17.6 Â 10 À5 mol L À1 ) determined by FAAS were diluted in 0.1 mol L À1 acetic acid solution (pH = 3.0) for measurements.…”

“…To evaluate the applicability of the proposed electrode, the recovery of metallic ions was realized in the spiked samples of industrial wastewater, natural water for both metallic cations and human urine for Cd(II), as shown in Table 1. The concentration of Cd(II) in sediments was also determined by Thermospray Flame Furnace Atomic Absorption Spectrometry (TS-FF-AAS) [47,51] to verify the accuracy of the voltammetric method. It was found that the results obtained by CNPE-CTS-GA are in good agreement with the comparative method, as shown in Table 2.…”