Influence of sugar cane vinasse on the sorption and degradation of herbicides in soil under controlled conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da capacidade de infiltração de solos submetidos a diferentes tipos de manejo

Inadequate vegetation and soil management leads to physical changes that affect aquifer recharge. The Araripe Plateau feeds an elevated number of springs on its northern slope; however, there are indications that their yield is decreasing. Through this research, it was studied the infiltration capacity of soils under different types of management. Soil samples from 21 sites were grouped into four groups. Group 1 represents areas of preserved vegetation, the others, anthropized ones. It was observed that soil moisture and infiltration capacity are linearly well correlated with organic matter; mean soil moisture during the dry season was significantly higher for Group 1 than for the other groups, even during the rainy season and anthropized areas show low organic matter contents, soil moisture, and infiltration capacity, indicating modifications in the soil's structure that reduce aquifer recharge.

Morphological and Histochemical Characterization of Gill Filaments of the Brazilian Endemic Bivalve Diplodon expansus (Kuster, 1856) (Mollusca, Bivalvia, Hyriidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Estudo do nivel piezometrico por analise geoestatistica

160 groundwater bores in the Ribeirao Preto region were used to study the behaviour of the piezometric surface of the Botucatu Formation aquifer by geostatistical methodology. The semi-variogram showed the following results: nugget = 50 m2; sill = 450 m2 and range = 4.5 km. The piezometric surface, obtained by punctual kriging in a 100 x 100 knot grid, revealed two lowered zones: one in a southwest to north-northeastern trend, indicating the groundwater flow north toward the Rio Pardo; and the other in the central part due to the high concentration of holes in the urban region of Ribeirao Preto city. -from English summary

The behavior of dissolved uranium in groundwaters of the Morro do Ferro thorium deposit, Brazil

Groundwater samples were collected for several months in boreholes drilled at Morro do Ferro, a thorium and rare earth deposit located on the Poços de Caldas Plateau, Minas Gerais State, Brazil. An aquifer system has developed in the weathered mantle due to in situ intense alteration. The weathered zone includes a thick argillaceous laterite greater than 100 m thick. The U content and 324U/238U activity ratio were measured in the groundwater samples and in spoil samples of a borehole drilled in the ore body. Some possible mechanisms related to the mobilization of uranium are considered such as complexation with humic substances and adsorption by clays. © 1989.

Obtencao e interpretacao de dados de Reflexao Sismica Superficial (Rasa) - exemplos e aplicacoes

Successful application of shallow seismic reflection method is related directly to the ability of the ground to transmit high-frequency seismic energy from a seismic source. The dominant frequencies of reflection data are in the range of 50 to 100 Hz and depend on the surface materials and water table. A spread of geophones send the siemsic signal to be recorded on a 12, 24 or 48 channel portable seismograph, using a single high-frequency geophone per channel. Although it is possible to find seismographs with display and processing unities, it is also possible to transfer digitalized data to a personal computer to be processed and interpreted by using specific programs. Some results of two recent field studies to specify the underground structure in the tidal flats area of Baie St. Paul (Quebec-Canada) and in glacial terrains, in the Waterloo (Ontario-Canada) region. -from English summary

Geothermal investigations in an area of induced seismic activity, northern São Paulo State, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Pollution by hexachlorobenzene and pentachlorophenol in the coastal plain of São Paulo state, Brazil

Organochlorine compounds were dumped by chemical industries during the 1970s in many areas of the coastal plain of São Paulo state in Brazil. These dumps, located on hillsides and in valleys, in both rural and urban environments, are responsible for soil and water pollution. The objective of this work was to determine how the pollutants have spread in an area occupied by a spodosol-type soil mantle. The study combines soil morphological observations with soil and water analysis of hexachlorobenzene (HCB) and pentachlorophenol (PCP) in soil toposequences. The results indicate that the highest pollutant concentrations are observed near the dump site and that the compounds contamination is increasing. A map integrating topography and chemical concentrations was created to visualize the spatial distribution of HCB levels in the landscape. Physical and chemical analyses were performed to measure HCB and PCP levels in the soil. Soil water appears to act as a vector of HCB, probably through complexation with and dispersal of dissolved organic matter. The persistence of HCB at the studied site is most likely due to the low pH values in combination with a high content of organic matter. HCB was consistently found in higher concentrations than PCP. It is plausible that the cause of this difference is that PCP is degraded more easily under sunlight than HCB and that degradation of PCP under acid conditions leads to the formation of HCB. © 2003 Published by Elsevier B.V.

Investigação de Intrusão de Água Salgada em Aqüífero Superficial a Partir de Medidas de Resistividade Elétrica

A site investigation program was carried out to detect salt-water intrusions in a shallow sedimentary aquifer based on electrical resistivity measurements. The site is located close to Paranaguá harbor, in the Paraná State, Brasil. At this site, high chloride concentration contaminated shallow water wells used to supply water for local industries. The site investigation program included a fieldwork, dipole-dipole electrical profiling, resistivity piezocone tests, physical-chemical analysis of sampled water and interpretation of borehole logs. The resistivity piezocone tests provided two simultaneous information; the soil stratigraphy at a very detailed level and a quasi-continuous resistivity profile. Both information adequately complemented dipole-dipole electrical profiling test data. The integration of all test data allowed identifying the contaminated areas as well as guided the location of new water wells to be installed in this area.

Resistivity (DC) method applied to aouifer protection studies

Resistivity (DC) method using vertical electrical soundings (Schlumberger array) are conducted In the vicinity of Canoas/RS, applied to environmental studies with the objective of Investigating groundwater conditions, The present paper shows a geoelectrlcal Identification of the lithology and an estimate of the relationship between the resistivity and Dar Zarrouk parameters (transverse unit resistance and longitudinal unit conductance) with the properties such as aquifer transmlssivlty and protection of ground water resources, In the saturated sediments, resistivity values defined the following sequence: clay layers (resistivity < 40 ohm-m) and sand layers (resistivity > 40 ohm-m), Two sand layers were identified; one corresponding to the unconfined aquifer and another to the confined aquifer between two clay layers, In the map of the transverse unit resistance of the unconfined aquifer, the tendencies of high values can be associated with the zones of high transmissivity; hence, these zones are suggested for the installation of monitoring wells, The map of longitudinal conductance Illustrates the Impermeability of the confining clay layer, Values of S > 1.0 siemens would indicate zones in which the confined aquifer would be protected; In comparison, values of S < 1.0 siemens would indicate zones of probable risks of contamination. © 2006 Sociedade Brasileira de Geofísica.

Resistivity piezocone for geo-environmental site characterization: Two case histories from Brazil

This paper presents two case histories from Brazil where geophysical and resistivity piezocone tests were carried out to detect contamination. At the first one, the site investigation program was carried out to detect salt-water intrusions in a superficial sedimentary aquifer, at the Paranaguá harbor, in Paraná State. The second case history is a sanitary landfill from Bauru City, São Paulo State. In both sites, superficial geophysical tests were interpreted to detect and delineate the shape of contamination plume, helping to locate the resistivity piezocone tests. It was found that the interpretation of resistivity piezocone tests is straightforward to assess salt-water intrusion in sedimentary sands. For tropical soils, this technique presented some limitations since the groundwater table sometimes is deeper than the layer penetratable to the cone. Moreover, the genesis of those soils affects soil behavior and soil and water sampling is required to support interpretation.

Avaliação do processo de fluoretação nos sistemas de abastecimento de água da região de Araçatuba, São Paulo

This paper focuses on the drinking-water fluoridation process in Araçatuba region water supply systems by means of 5.157 fluoride concentration data from 2001 to 2005. These data were studied based on the water source, the administration and the structure of the water supply system, according to the population of the county and the type of management. Almost half of samples did not comply the fluoridation standard and the higher compliance was verified in the water supply systems operated by Sabesp (69%), followed by the group of Large counties (52%), statistically similar to the Medium ones (51.4%), and better than the Small ones (28%). The systems with surface intakes showed statistically higher performance in the compliance to the standard (60%) compared to the ones that use groundwater (42.9%). In this last group, those that explore the Guarani aquifer were superior (52.3%) than the others (46.6%).

Pré-oxidação e adsorção em carvão ativado granular para remoção dos herbicidas Diuron e Hexazinona de água subterrânea

The cultivation of sugarcane demands the use of herbicides such as Diuron and Hexazinone. Some supply wells from Ribeirão Preto, SP, Brazil, built in the Guarani Aquifer are located in recharge points, and the presence of sandy Quartzarenic Neosol in these areas increases the vulnerability of the groundwater to contamination from herbicides This paper reports the water quality monitored in some wells located in the recharge area and the removal of Diuron and Hexazinone by means of adsorption in granular activated carbon (GAC), preceded or not by preoxidation with chlorine and chlorine dioxide in a pilot plant. The results indicated that Diuron was more strongly adsorbed than Hexazinone and that the saturation time of the GAC in the test with preoxidation was shorter than in the test without preoxidation, which may have occurred mainly due to the formation of by-products that competed with the adsorption of the herbicides.

Hidrogeoquímica do aqüífero guarani na área urbana de ribeirão preto (SP)

This work evaluated the hydrogeochemistry of the Guarani Aquifer in the urban area of Ribeirão Preto, São Paulo State. Thirty one sampling points were established and it was carried out field campaigns in 7 and 8 July 2005, analyzing the following parameters: conductivity, temperature, pH, turbidity, color, dry residue, dissolved oxygen, Ca2+, Mg2+, Na+, K+, Fe3+, Al3+, HCO3-, SO42-, PO43-, NO3-, Cl- and F-. The results indicated that the groundwaters in the urban area of Ribeirão Preto pH possess slightly acid, low conductivity, turbidity, color and dissolved oxygen inside the limits established for drinking waters. The ionic composition indicated that the groundwaters have low cations and anions concentration, being they classified as soft water and calcium-bicarbonated. Statistical tests suggested that conductivity and pH are controlled for the calcite dissolution (CaCO3) during the water/rock interaction process. Besides, it is possible to conclude that the high NO3- and PO43- concentrations found in the groundwater in the urban area of Ribeirão Preto are originated due to anthropogenic activities.

Litogeoquímica E aspectos Petrogenéticos dos basaltos da Província Magmática do Paraná na porção centro-norte do Estado de São Paulo

The petrographic and geochemical characterization of flood basalts of Serra Geral Formation are here presented. The investigated areas are situated in four different regions of São Paulo state: Jaú, Ribeirão Preto, Franca and Fernandópolis. They represent almost the total area of outcrops of basalts in the São Paulo State. The petrographical data reveals that these rocks are constituted mainly by plagioclase (30-40%), pyroxenes, augite and pigeonita (20-30%) and magnetite (5-15%), and show a intergranular texture and its varieties intersertal, hialophitic and pilotaxitic. The geochemical data show a basic and tholeiitic affinity of the studied basalts, with high-Ti content (TiO2 > 1.8%), typical of the northern region of Paraná Basin. Three different magma-types were recognized: Paranapanema, Urubici and Pitanga. The first magma-type is concentrated in the Fernandópolis region, the second in the Franca region, and the Pitanga occurs in the Ribeirão Preto and Jaú regions. The distribution patterns of these magma-types and the detailed study of geochemical data showed that they are, probably, generated by a melting of a continental lithospheric mantle.