Determination of the Lead, Cadmium, and Chromium Concentration in Mineral Feeds and Supplements for Cattle Produced in the Mato Grosso State, Brazil.

This work aimed to determine the concentration of lead (Pb), cadmium (Cd), and chromium (Cr) in mineral feeds and supplements for cattle produced in the Mato Grosso State, Brazil. Three different lots of nine mineral supplements and eleven mineral feeds were collected, and the samples were prepared by wet decomposition and quantified by flame atomic absorption spectrometry. The limits of detection and quantification ranged from 0.

Comparative analysis of physicochemical properties of root perforation sealer materials.

Objectives: This study evaluated the solubility, dimensional alteration, pH, electrical conductivity, and radiopacity of root perforation sealer materials.

Materials And Methods: For the pH test, the samples were immersed in distilled water for different periods of time. Then, the samples were retained in plastic recipients, and the electrical conductivity of the solution was measured.

Comparative Analysis of Selected Physicochemical Properties of Pozzolan Portland and MTA-Based Cements.

Physicochemical properties of pozzolan Portland cement were compared to ProRoot MTA and MTA BIO. To test the pH, the samples were immersed in distilled water for different periods of time. After the pH analysis, the sample was retained in the plastic recipient, and the electrical conductivity of the solution was measured.

Assessment of metolachlor and diuron leaching in a tropical soil using undisturbed soil columns under laboratory conditions.

In the present study, diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-metoxi-1-methylethyl)acetamide] leaching was studied in undisturbed soil columns collected in a cotton crop area in Mato Grosso State, Brazil. The pesticides were applied to the soil surface in dosages similar to those used in a cotton plantation. To assess the leaching process, soil columns were submitted to simulated rain under laboratory conditions at 25 ± 3°C, in the absence of wind and direct solar radiation.

Soil remediation using a coupled process: soil washing with surfactant followed by photo-Fenton oxidation.

In the present work the use of a coupled process, soil washing and photo-Fenton oxidation, was investigated for remediation of a soil contaminated with p,p'-DDT (DDT) and p,p'-DDE (DDE), and a soil artificially contaminated with diesel. In the soil washing experiments, Triton X-100 (TX-100) aqueous solutions were used at different concentrations to obtain wastewaters with different compositions. Removal efficiencies of 66% (DDT), 80% (DDE) and 100% (diesel) were achieved for three sequential washings using a TX-100 solution strength equivalent to 12 times the effective critical micelle concentration of the surfactant (12 CMC(eff)).

Environmental implications of soil remediation using the Fenton process.

This work evaluates some collateral effects caused by the application of the Fenton process to 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) and diesel degradation in soil. While about 80% of the diesel and 75% of the DDT present in the soil were degraded in a slurry system, the dissolved organic carbon (DOC) in the slurry filtrate increased from 80 to 880mgl(-1) after 64h of reaction and the DDT concentration increased from 12 to 50microgl(-1). Experiments of diesel degradation conducted on silica evidenced that soluble compounds were also formed during diesel oxidation.