The aim of this work is to study metal and As concentrations in soil due to ash deposition from a coal plant at Figueira (PR), evaluating the macroelement (Al, Ca, Fe, Mg, Mn, Ti, V) and microelement (As, Cd, Co, Cr, Cu, Mo, Ni, Pb, Zn) concentrations in the soil around the coal plant. The plant operation caused a slight increase in the majority of the metal concentrations in the top soil close to the plant (up to 1 km) in the wind direction (NW). The elements As, Cd, Mo, Pb and Zn are considered likely soil pollutants, and As is considered the only critical element.

The aim of this study was to evaluate the behavior of Zn and Mn in a soil column. Two soil columns were sampled, and four opened alkaline batteries were placed at the top of one soil column. An acid-rainwater solution (HNO3 and H2SO4; pH 4) was percolated through the battery contaminated column during one year. The results showed that the leaching of alkaline batteries caused enrichment of 70 and 11 times in the Zn and Mn concentration of the topsoil, respectively. Additionally, leaching of electrolyte (KOH) from the batteries increased the soil pH in the contaminated column.

Leaking of diesel oil from gas stations is frequent in Brazil. The presence of polycyclic aromatic hydrocarbons (PAHs), which are highly toxic is an indication of contamination by heavy hydrocarbons from diesel oil. Here were present the determination of the distribution coefficient (Kd) of benzo(a)pyrene (the most carcinogenic of the PAHs) in tropical soils using the sorption isotherm model. The sorption curves acquired for benzo(a)pyrene were of the S-type, probably due to the water/methanol experimental conditions. The sorption curves allowed calculation of the distribution coefficient (Kd). The experimental Kd values were lower than those calculated from literature Koc values (partition coefficient normalized by organic carbon), due mainly to the cosolvency effect and the percentage of organic matter and clay in soil.

The effect of synthetic zeolites on stabilizing Zn-contaminated soil using 0.01 mol L-1 CaCl2 leaching solution in batch experiments was investigated. The zeolites were synthesized from coal ash by hydrothermal treatment with alkaline solution. The additive enhanced the sorption capacity of the soil and reduced leaching. Zinc leaching was reduced by more than 80% using a minimum of 10% additive. The higher cation exchange capacity of the zeolite/soil mixtures and higher pH were responsible for stabilizing Zn in soil. The poly(2-aminobenzenesulfonic acid)-coated mercury thin-film electrode was used for the determination of zinc.

Foram analisadas onze amostras de solo do Parque Estadual da Cantareira para avaliar a influência do tráfico veicular. Determinou-se para todos os solos a concentração total, parcial e biodisponível de (Na, Al, Ca, Mg, K, Si, Ti, Mn, Cr, Ni, Cu, Zn, As, Cd, Pb). Até a data da amostragem não foram observadas influências das rodovias sobre a concentração dos metais no solo. A única exceção ocorreu no solo do ponto 3 (alta porcentagem de argila 64% e matéria orgânica 6,4%) onde se encontrou a mais alta concentração de Cr (74,5 e 94,5 mg kg-1), Ni (22,5 e 54,8 mg kg-1), Cu (83,8 e 121 mg kg-1), Cd (1,28 e 1,74 mg kg-1) e As (2,04 e 2,67 mg kg-1) na fração A (0-20 cm) e B (20-40 cm) respectivamente, do que nos demais solos, provavelmente estes elementos provem de outra fonte poluidora. A seqüência dos microelementos biodisponíveis na fração A do solo foi As > Cd > Zn > Cu > Pb > Ni > Cr.

Eleven soil samples within the Cantareira State Park were analyzed to evaluate the traffic influence. For all soil samples total, partial and bioavailable concentration of (Na, Al, Ca, Mg, K, Si, Ti, Mn, Cr, Ni, Cu, Zn, As, Cd, Pb) were determined. No influence from the highways in metals concentration in the soil could be observed up to sampling date. The only exception occurred in soil point 3 (high clay 64% and organic matter 6.4%), that presented higher concentration of Cr (74.5 and 94.5 mg kg-1), Ni (22.5 and 54.8mg kg-1), Cu (83.8 and 121 mg kg-1), Cd (1.28 and 1.74 mg kg-1) and As (2.04 and 2.67 mg kg-1), in fraction A (0-20 cm) and B (20-40 cm) respectively than the others ones, probably these elements came from other pollutant source. The availability sequence of the microelements in fraction A of the soil was As > Cd > Zn > Cu > Pb > Ni > Cr.

Rainwater samples were analyzed during a one-year period (June 1999 - June 2000) and presented concentration of pH = 4.9 (volume weight mean). The ions concentrations results showed a high sulfate concentration (35 µmol L-1), followed by the cations concentration of sodium, calcium and ammonium (35, 16 and 30 µmol L-1, respectively). Due to the great contribution of these cations in the sulfate neutralization action, the rainwater of this region had only a light acid characteristic. The soil characteristic was acid and the bioavailable concentration of the alkaline cations (Ca, Mg and K) presented high calcium concentrations (1001 ± 357 mg kg-1) compared with the other cations. The determination of soil sensitivity to acid rain was calculated by the ratio BC/Al3+ (BC = Ca2+ + Mg2+ + K+) and presented the average value of 5.1 ± 3.3. This preliminary evaluation of soil susceptibility by the ratio BC/Al3+ showed that the local soil and vegetation type (tropical Savannah) were sensitive to acid deposition. The long term of this impacting condition (acid rain, high sulfate deposition) could be harmful to the soil and vegetation quality.