&... more <p>The town of Santo Amaro, in the state of Bahia, Brazil, presents a history of contamination, mainly of lead (Pb) originating from the intense activity of metallurgical extraction by the mining company “Plumbum-Mineração e Metalurgia Ltda.” between the years of 1956 and 1993. Over this period, the lead slag was deposited carelessly in the factory area, creating a huge hazardous waste site. Subsequently, the problem increased when this slag was used as the basis for the paving of city streets, gardens, and school yards due to its granular characteristic and good support capacity. However, the ongoing need to remove the street paving for work on the water and sewage networks requires the exposure of the slag, making it a source of active contamination. In this context, the Ground Penetrating Radar (GPR) method was used as a tool to support and guide the evaluation of the existence of anomalous areas associated with the source of local contamination (slag) under the paving. In this work the data was acquired by moving the GPR using the of constant offset technique and a sampling interval of 5 cm between the traces. The shoots and trace records were registered continuously with the use of a calibrated wheel. The results obtained by this study show the potential of applying the GPR method to the environmental characterization of the subsoil of paved streets, making it possible to identify the resistive material contaminants (lead slag) as well as the various layers: paving, soil-slag, and massapê soil. These layers are characterized by distinct reflection patterns. The first observed reflection pattern has high amplitude with horizontal and continuous reflectors, which correspond to a characteristic pattern of urban street paving. The second reflection pattern is characterized by reflectors with amplitude variations (horizontal and inclined, continuous and discontinuous), which indicate the heterogeneity of the medium and corresponds to the soil pattern mixed with the resistive slag material. The third reflection pattern is characterized by low amplitude with chaotic and totally discontinuous reflectors, and occurs just below the second reflection pattern. This pattern of reflection marks the region in which the electromagnetic GPR signal is absorbed by the medium. This absorption is an effect of the attenuation of the electromagnetic signal by the presence of electrically conductive layers of the characteristic massapê soil (clayey to very clayey) of the study area. GPR data also enabled the identification of reflectors associated with anthropogenic interferences (manholes, train lines, pipelines, etc.). Borehole samples confirmed the existence of the contaminant (lead slag). Anomalous concentrations of heavy metals, mainly lead, were observed in the locations indicated by geophysical results using the GPR method, showing the importance of the use of geophysics in environmental characterization programs.</p>
Proceedings of the 2 Simpósio Brasileiro de Geofísica
Contents of this paper were reviewed by the Technical Committee of the 2 nd Symposium Brazilian G... more Contents of this paper were reviewed by the Technical Committee of the 2 nd Symposium Brazilian Geophysical. Ideas and concepts of the text are authors responsibility and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
In Brazil, until the 1970s, industrial and urban waste was directly disposed of in the soil, as i... more In Brazil, until the 1970s, industrial and urban waste was directly disposed of in the soil, as it was believed that the soil was an unlimited receptor for disposable and noxious substances. However, this capability was overestimated, causing irreparable damage to the environment. Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, contributing to the greater efficiency of soundings programs and the installation of monitoring wells. In this work we have evaluated the potential of the Ground Penetrating Radar (GPR) method in the characterization of a hazardous waste site generated by the lead ore processing, where the slag resulting from this process was used to pave streets and backyard residences in the town of Santo Amaro, state of Bahia, situated on the domain of the massapê soil. The used method enabled the identification of geophysical anomalies, which characterized the presence of contamination from slag material. It was also possible to define the interface between the paving and the soil-slag, as well as the interface between the soil-slag and the massapê soil. Chemical analysis of the soil confirmed the contamination, with high concentrations of lead found in at least three drill holes. The geophysical method used in the investigation provided an excellent tool for environmental characterization of the area, and could be applied in the study of similar areas elsewhere. Geophysical investigation using the GPR method: a case study on the contamination of lead in the Santo Amaro town, Bahia, Brazil
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Elis (IAG/USP) 110 p + anexos-Dissertação (Mestrado)-Defesa 03.02.2004 RESUMO. O presente trabalh... more Elis (IAG/USP) 110 p + anexos-Dissertação (Mestrado)-Defesa 03.02.2004 RESUMO. O presente trabalho tem por objetivo a aplicação integrada de metodologias geofísicas visando a caracterização geoelétrica daárea utilizada para disposição de resíduos sólidos urbanos na cidade de Bauru-SP. Para estudar o local e avaliar a existência do problema da contaminação foram utilizados os métodos geofísicos da eletrorresistividade, polarização induzida e potencial espontâneo. O Aterro Sanitário, geologicalmente, está posicionado sobreárea de afloramento de arenitos do Grupo Bauru. Este atributo litológicoé considerado impróprio para implantação desse tipo de empreendimento, segundo Zuquette et al. (1994). O Inventário Estadual de Resíduos Sólidos Domiciliares de 2002, apresentado pela Companhia de Tecnologia de Saneamento Ambiental-CETESB, enquadra como adequada a instalação de destinação de resíduos sólidos urbanos na cidade de Bauru. Os métodos da eletrorresistividade e polarização induzida permitiram identificar anomalias, dentro da zona saturada, que caracterizam a presença da contaminação gerada pela migração do percolado proveniente da cava preenchida com resíduos. Essa contaminaçãoé confirmada pelos métodos de investigação direta (análise daágua coletada nos poços de monitoramento permanente e sondagens de piezocone de resistividade). O grande intervalo de variação dos valores de potencial espontâneo intensa atividade geoquímica naárea de estudo. Os métodos geofísicos utilizados forneceram um grande número de informações sobre as diversas características relacionadasà intenção entre aárea de disposição de resíduos sólidos urbanos e o meio físico.
Geophysics has shown effectiveness in identify areas contaminated by urban solid wastes, contribu... more Geophysics has shown effectiveness in identify areas contaminated by urban solid wastes, contributing to become more effective sounding programs directed to collect of samples and installation of monitoring systems. In this context, this work had as purpose evaluating the potentialities of the integration of geophysical methods (resistivity, induced polarization and self-potential) in the environmental characterization of the area of the sanitary landfill of the city of Bauru-SP. The selfpotential method allowed to detect the direction of the underground flow. The resistivity and induced polarization methods allowed to identify anomalies inside of the saturated zone, that characterize the presence of contamination generated for the migration of the percolated proceeding of the disposal of solid waste. This contamination is confirmed by direct investigation (chemical analysis of the water collected in the monitoring wells). The geophysical methods used had supplied a great number of information about the several characteristics related to interaction between waste disposal area and environment.
A variety of environmental problems occurs due to the inadequate disposition of residues. Applied... more A variety of environmental problems occurs due to the inadequate disposition of residues. Applied geophysics methodologies to environmental studies show great results in the investigation of contaminating. GPR is a practical and fast geophysical method in such investigations, because the electromagnetic signal assists in the delimitation of the contaminating, addressing direct techniques of investigation (boreholes and wells). This study was developed in an old disposition area to residues lubricants oils (dense nonaqueous phase liquids-DNAPL) in the municipal district of Ribeirão Preto, São Paulo State. This area is situated in the geological domains of the basaltic floods of the Serra Geral Formation and sandstones of the Botucatu Formation. GPR acquisition was carried out inside and next to 4 ditches of residues disposition, with 100 MHz unshielded antennas, enabling a maximum investigation depth of 7 meters. The limits and of the ditches base can be identify in the GPR sections, except in the ditch 1, which the base is not delineated by GPR. The results show that GPR signal is much attenuated below ditches. This fact could be result of a bacteriological activity in the residue or increase of dissolved salts in the soil caused by acid pH of the residue.
Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, co... more Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, contributing to the greater efficiency of soundings programs and the installation of monitoring wells. In the study area, four trenches were constructed with a total volume of about 25,000 m 3. They were almost totally filled with re-refined lubricating oil waste for approximately 25 years. No protection liners were used in the bottoms and laterals of the disposal trenches. The purpose of this work is to evaluate the potential of the resistivity and ground penetrating radar (GPR) methods in characterizing the contamination of this lubricant oil waste disposal area in Ribeirão Preto, SP, situated on the geological domain of the basalt spills of the Serra Geral Formation and the sandstones of the Botucatu Formation. Geophysical results were shown in 2D profiles. The geophysical methods used enabled the identification of geophysical anomalies, which characterized the contamination produced by the trenches filled with lubricant oil waste. Conductive anomalies (smaller than 185 Xm) immediately below the trenches suggest the action of bacteria in the hydrocarbons, as has been observed in several sites contaminated by hydrocarbons in previously reported cases in the literature. It was also possible to define the geometry of the trenches, as evidenced by the GPR method. Direct sampling (chemical analysis of the soil and the water in the monitoring well) confirmed the contamination. In the soil analysis, low concentrations of several polycyclic aromatic hydrocarbons (PAHs) were found, mainly naphthalene and phenanthrene. In the water samples, an analysis verified contamination of the groundwater by lead (Pb). The geophysical methods used in the investigation provided an excellent tool for environmental characterization in this study of a lubricant oil waste disposal area, and could be applied in the study of similar areas.
&... more <p>The town of Santo Amaro, in the state of Bahia, Brazil, presents a history of contamination, mainly of lead (Pb) originating from the intense activity of metallurgical extraction by the mining company “Plumbum-Mineração e Metalurgia Ltda.” between the years of 1956 and 1993. Over this period, the lead slag was deposited carelessly in the factory area, creating a huge hazardous waste site. Subsequently, the problem increased when this slag was used as the basis for the paving of city streets, gardens, and school yards due to its granular characteristic and good support capacity. However, the ongoing need to remove the street paving for work on the water and sewage networks requires the exposure of the slag, making it a source of active contamination. In this context, the Ground Penetrating Radar (GPR) method was used as a tool to support and guide the evaluation of the existence of anomalous areas associated with the source of local contamination (slag) under the paving. In this work the data was acquired by moving the GPR using the of constant offset technique and a sampling interval of 5 cm between the traces. The shoots and trace records were registered continuously with the use of a calibrated wheel. The results obtained by this study show the potential of applying the GPR method to the environmental characterization of the subsoil of paved streets, making it possible to identify the resistive material contaminants (lead slag) as well as the various layers: paving, soil-slag, and massapê soil. These layers are characterized by distinct reflection patterns. The first observed reflection pattern has high amplitude with horizontal and continuous reflectors, which correspond to a characteristic pattern of urban street paving. The second reflection pattern is characterized by reflectors with amplitude variations (horizontal and inclined, continuous and discontinuous), which indicate the heterogeneity of the medium and corresponds to the soil pattern mixed with the resistive slag material. The third reflection pattern is characterized by low amplitude with chaotic and totally discontinuous reflectors, and occurs just below the second reflection pattern. This pattern of reflection marks the region in which the electromagnetic GPR signal is absorbed by the medium. This absorption is an effect of the attenuation of the electromagnetic signal by the presence of electrically conductive layers of the characteristic massapê soil (clayey to very clayey) of the study area. GPR data also enabled the identification of reflectors associated with anthropogenic interferences (manholes, train lines, pipelines, etc.). Borehole samples confirmed the existence of the contaminant (lead slag). Anomalous concentrations of heavy metals, mainly lead, were observed in the locations indicated by geophysical results using the GPR method, showing the importance of the use of geophysics in environmental characterization programs.</p>
Proceedings of the 2 Simpósio Brasileiro de Geofísica
Contents of this paper were reviewed by the Technical Committee of the 2 nd Symposium Brazilian G... more Contents of this paper were reviewed by the Technical Committee of the 2 nd Symposium Brazilian Geophysical. Ideas and concepts of the text are authors responsibility and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
In Brazil, until the 1970s, industrial and urban waste was directly disposed of in the soil, as i... more In Brazil, until the 1970s, industrial and urban waste was directly disposed of in the soil, as it was believed that the soil was an unlimited receptor for disposable and noxious substances. However, this capability was overestimated, causing irreparable damage to the environment. Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, contributing to the greater efficiency of soundings programs and the installation of monitoring wells. In this work we have evaluated the potential of the Ground Penetrating Radar (GPR) method in the characterization of a hazardous waste site generated by the lead ore processing, where the slag resulting from this process was used to pave streets and backyard residences in the town of Santo Amaro, state of Bahia, situated on the domain of the massapê soil. The used method enabled the identification of geophysical anomalies, which characterized the presence of contamination from slag material. It was also possible to define the interface between the paving and the soil-slag, as well as the interface between the soil-slag and the massapê soil. Chemical analysis of the soil confirmed the contamination, with high concentrations of lead found in at least three drill holes. The geophysical method used in the investigation provided an excellent tool for environmental characterization of the area, and could be applied in the study of similar areas elsewhere. Geophysical investigation using the GPR method: a case study on the contamination of lead in the Santo Amaro town, Bahia, Brazil
Proceedings of the 16th International Congress of the Brazilian Geophysical Society&Expogef
Contents of this paper were reviewed by the Technical Committee of the 16 th International Congre... more Contents of this paper were reviewed by the Technical Committee of the 16 th International Congress of the Brazilian Geophysical Society and do not necessarily represent any position of the SBGf, its officers or members. Electronic reproduction or storage of any part of this paper for commercial purposes without the written consent of the Brazilian Geophysical Society is prohibited.
Elis (IAG/USP) 110 p + anexos-Dissertação (Mestrado)-Defesa 03.02.2004 RESUMO. O presente trabalh... more Elis (IAG/USP) 110 p + anexos-Dissertação (Mestrado)-Defesa 03.02.2004 RESUMO. O presente trabalho tem por objetivo a aplicação integrada de metodologias geofísicas visando a caracterização geoelétrica daárea utilizada para disposição de resíduos sólidos urbanos na cidade de Bauru-SP. Para estudar o local e avaliar a existência do problema da contaminação foram utilizados os métodos geofísicos da eletrorresistividade, polarização induzida e potencial espontâneo. O Aterro Sanitário, geologicalmente, está posicionado sobreárea de afloramento de arenitos do Grupo Bauru. Este atributo litológicoé considerado impróprio para implantação desse tipo de empreendimento, segundo Zuquette et al. (1994). O Inventário Estadual de Resíduos Sólidos Domiciliares de 2002, apresentado pela Companhia de Tecnologia de Saneamento Ambiental-CETESB, enquadra como adequada a instalação de destinação de resíduos sólidos urbanos na cidade de Bauru. Os métodos da eletrorresistividade e polarização induzida permitiram identificar anomalias, dentro da zona saturada, que caracterizam a presença da contaminação gerada pela migração do percolado proveniente da cava preenchida com resíduos. Essa contaminaçãoé confirmada pelos métodos de investigação direta (análise daágua coletada nos poços de monitoramento permanente e sondagens de piezocone de resistividade). O grande intervalo de variação dos valores de potencial espontâneo intensa atividade geoquímica naárea de estudo. Os métodos geofísicos utilizados forneceram um grande número de informações sobre as diversas características relacionadasà intenção entre aárea de disposição de resíduos sólidos urbanos e o meio físico.
Geophysics has shown effectiveness in identify areas contaminated by urban solid wastes, contribu... more Geophysics has shown effectiveness in identify areas contaminated by urban solid wastes, contributing to become more effective sounding programs directed to collect of samples and installation of monitoring systems. In this context, this work had as purpose evaluating the potentialities of the integration of geophysical methods (resistivity, induced polarization and self-potential) in the environmental characterization of the area of the sanitary landfill of the city of Bauru-SP. The selfpotential method allowed to detect the direction of the underground flow. The resistivity and induced polarization methods allowed to identify anomalies inside of the saturated zone, that characterize the presence of contamination generated for the migration of the percolated proceeding of the disposal of solid waste. This contamination is confirmed by direct investigation (chemical analysis of the water collected in the monitoring wells). The geophysical methods used had supplied a great number of information about the several characteristics related to interaction between waste disposal area and environment.
A variety of environmental problems occurs due to the inadequate disposition of residues. Applied... more A variety of environmental problems occurs due to the inadequate disposition of residues. Applied geophysics methodologies to environmental studies show great results in the investigation of contaminating. GPR is a practical and fast geophysical method in such investigations, because the electromagnetic signal assists in the delimitation of the contaminating, addressing direct techniques of investigation (boreholes and wells). This study was developed in an old disposition area to residues lubricants oils (dense nonaqueous phase liquids-DNAPL) in the municipal district of Ribeirão Preto, São Paulo State. This area is situated in the geological domains of the basaltic floods of the Serra Geral Formation and sandstones of the Botucatu Formation. GPR acquisition was carried out inside and next to 4 ditches of residues disposition, with 100 MHz unshielded antennas, enabling a maximum investigation depth of 7 meters. The limits and of the ditches base can be identify in the GPR sections, except in the ditch 1, which the base is not delineated by GPR. The results show that GPR signal is much attenuated below ditches. This fact could be result of a bacteriological activity in the residue or increase of dissolved salts in the soil caused by acid pH of the residue.
Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, co... more Geophysics has been shown to be effective in identifying areas contaminated by waste disposal, contributing to the greater efficiency of soundings programs and the installation of monitoring wells. In the study area, four trenches were constructed with a total volume of about 25,000 m 3. They were almost totally filled with re-refined lubricating oil waste for approximately 25 years. No protection liners were used in the bottoms and laterals of the disposal trenches. The purpose of this work is to evaluate the potential of the resistivity and ground penetrating radar (GPR) methods in characterizing the contamination of this lubricant oil waste disposal area in Ribeirão Preto, SP, situated on the geological domain of the basalt spills of the Serra Geral Formation and the sandstones of the Botucatu Formation. Geophysical results were shown in 2D profiles. The geophysical methods used enabled the identification of geophysical anomalies, which characterized the contamination produced by the trenches filled with lubricant oil waste. Conductive anomalies (smaller than 185 Xm) immediately below the trenches suggest the action of bacteria in the hydrocarbons, as has been observed in several sites contaminated by hydrocarbons in previously reported cases in the literature. It was also possible to define the geometry of the trenches, as evidenced by the GPR method. Direct sampling (chemical analysis of the soil and the water in the monitoring well) confirmed the contamination. In the soil analysis, low concentrations of several polycyclic aromatic hydrocarbons (PAHs) were found, mainly naphthalene and phenanthrene. In the water samples, an analysis verified contamination of the groundwater by lead (Pb). The geophysical methods used in the investigation provided an excellent tool for environmental characterization in this study of a lubricant oil waste disposal area, and could be applied in the study of similar areas.
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