Papers by Lourival C Paraiba
Pesticidas Revista De Ecotoxicologia E Meio Ambiente, 1997
Pesticidas Revista De Ecotoxicologia E Meio Ambiente, 1994
Pab, 2005
Resumo -O objetivo deste trabalho foi apresentar uma modelagem da distribuição ambiental de vinte... more Resumo -O objetivo deste trabalho foi apresentar uma modelagem da distribuição ambiental de vinte e nove poluentes orgânicos encontrados em amostras de lodos de esgoto das estações de tratamento de esgoto de Barueri e Suzano, SP. Lodos de esgoto são misturas de produtos orgânicos e inorgânicos gerados nos processos primários e secundários de tratamento que, mediante adequado controle de qualidade, podem ser reutilizados como fertilizantes agrícolas. O modelo de fugacidade nível I foi aplicado a um sistema compartimental hipotético constituído de ar, água, solo, sedimento, biota aquática e plantas. Foi utilizada a massa molecular, a pressão de vapor, a solubilidade em água, a constante de Henry, o coeficiente de partição octanol-água e a meia-vida no solo de cada um dos poluentes. O coeficiente de sorção no solo, os fatores de bioconcentração em organismos aquáticos, raízes e na seiva do xilema de plantas foram calculados por meio de expressões que correlacionam cada um desses parâmetros com o coeficiente de partição octanol-água do poluente. Foram estimados e usados os coeficientes de partição folha-ar e ar-água e o índice GUS de cada poluente. A modelagem e os cálculos dos fatores de bioconcentração e dos coeficientes de partição revelam os compartimentos preferenciais dos poluentes.
A mathematical model was developed to estimate the bioconcentration factor (BCF) of herbicides in... more A mathematical model was developed to estimate the bioconcentration factor (BCF) of herbicides in sugarcane juice. The model correlates the BCF of herbicides with a) water transpiration rate (Q); b) transpiration steam concentration factor of the herbicides (TSCF); c) partition coefficient of plant- water of the herbicides (KPW); d) plant fresh weight (M); e) metabolic and dilution rate of the herbicide in the plant (kE and kG) and f) the herbicide soil degradation rate (kS). The selected herbicides for the study are approved to be used in sugarcane for weed control. The model simulates herbicide uptake by transpiration flow and water uptake in sugarcane applied to a hypothetic crop grow and development. The herbicides selected were 2,4-D, acetochlor, ametryn, atrazine, clomazone, diuron, hexazinone, imazapic, imazapyr, isoxaflutole, metribuzin, pendimethalin, picloram, simazine, sulfentrazone, tebuthiuron and trifluralin. The model fitness was evaluated through the sensitivity anal...
Environmetrics, 2003
... and bubble functions, which is equivalent to the Petrov Galerkin method type (Johnson, 1987)... more ... and bubble functions, which is equivalent to the Petrov Galerkin method type (Johnson, 1987), and streamline upwind PetrovGalerkin methods ... Generally, the partition coefficient Kd is linear and directly related to the pesticide partition organic carbon coefficient Koc (m3 kgĀ1 ...
Computers & Mathematics with Applications, 2008
The numerical simulation of a level IV fugacity model coupled to a dispersion-advection equation ... more The numerical simulation of a level IV fugacity model coupled to a dispersion-advection equation to simulate the environmental concentration of a pesticide in rice fields is presented. The model simulates the dynamic distribution of the pesticide in a compartmental system constituted by air, water, rice plants and bottom sediment together with saturated soil layers. The level IV fugacity model is given by a linear system of ordinary differential equations that considers the fugacities and, consequently, the concentrations of the pesticide in air, water, rice plants and bottom sediment. The dispersion-advection equation simulates the pesticide leaching in the saturated layers of the soil, considering the hydrodynamic dispersion, the pesticide degradation rate and the soil pesticide absorption in the saturated soil layer.
Chemosphere, 2007
The model presented allows simulating the pesticide concentration evolution in fruit trees and es... more The model presented allows simulating the pesticide concentration evolution in fruit trees and estimating the pesticide bioconcentration factor in fruits. Pesticides are non-ionic organic compounds that are degraded in soils cropped with woody species, fruit trees and other perennials. The model allows estimating the pesticide uptake by plants through the water transpiration stream and also the time in which maximum pesticide concentration occur in the fruits. The equation proposed presents the relationships between bioconcentration factor (BCF) and the following variables: plant water transpiration volume (Q), pesticide transpiration stream concentration factor (TSCF), pesticide stem-water partition coefficient (K Wood,W ), stem dry biomass (M) and pesticide dissipation rate in the soil-plant system (k EGS ). The modeling started and was developed from a previous model ''Fruit Tree Model'' (FTM), reported by Trapp and collaborators in 2003, to which was added the hypothesis that the pesticide degradation in the soil follows a first order kinetic equation. The FTM model for pesticides (FTM-p) was applied to a hypothetic mango plant cropping (Mangifera indica) treated with paclobutrazol (growth regulator) added to the soil. The model fitness was evaluated through the sensitivity analysis of the pesticide BCF values in fruits with respect to the model entry data variability.
Applied Mathematical Modelling, 1998
A continuous time dynamic system of an unsteady state fugacity model is presented. Properties of ... more A continuous time dynamic system of an unsteady state fugacity model is presented. Properties of this model as stability are studied. In order to evaluate numerical results a discretization preserving the stability and yielding the positivity property of the model is used. Finally, algorithms to determine the values of the fugacities, the concentrations and the dissipation time are given. The above study is illustrated with numerical results in a three compartmental environmental system. Ó 1998 Elsevier Science Inc. All rights reserved.
A dispersion-advection equation, which is denominated DAPESTE model, of one-dimensional evolution... more A dispersion-advection equation, which is denominated DAPESTE model, of one-dimensional evolution to simulate pesticide leaching in soil with sinusoidal function to describe the daily average soil temperature at different depths will be presented. In numerical simulation, the Finite Elements Method (FEM) will be used for the space semi-discretization and the Backward Eüler Method for time discretization. It will be used appropriated FEM for dispersion-advection problems in which the predominat advective transport over the dispersive one. Let us suppose that the pesticide diffusivities in the gaseous and aqueous soil phases depend on the soil temperature. In this way, the effective hydrodynamic dispersion coefficient of the dispersion-advection equation will depend on the soil temperature. The pesticide air-water partition coefficient of the Henry law, varying with the temperature, will be determined by the Clausius-Clapeyron equation. The van't Hoff equation will be used to determine the temperature dependence of the pesticide soil sorption coefficient. The Arrhenius equation will be used to estimated the effect of the soil temperature on the pesticide degradation rate. These temperature dependence relationships can help comprehend the pesticide behavior in the soil under different scenarios of the soil temperatures, especially in pesticide concentration leaching and its half-life in soil.
Chemosphere, 2002
The effect of annual variation of daily average soil temperature, at different depths, in calcula... more The effect of annual variation of daily average soil temperature, at different depths, in calculating pesticides ranking indexes retardation factor and attenuation factor is presented. The retardation factor and attenuation factor are two site-specific pesticide numbers, frequently used as screening indicator indexes for pesticide groundwater contamination potential. Generally, in the calculation of these two factors are not included the soil temperature effect on the parameters involved in its calculation. It is well known that the soil temperature affects the pesticide degradation rate, water-air partition coefficient and water-soil partition coefficient. These three parameters are components of the retardation factor and attenuation factor and contribute to determine the pesticide behavior in the environment. The Arrhenius equation, van't Hoff equation and Clausius-Clapeyron equation are used in this work for estimating the soil temperature effect on the pesticide degradation rate, water-air partition coefficient and soil-water partition coefficient, respectively. These dependence relationships, between results of calculating attenuation and retardation factors and the soil temperature at different depths, can aid to understand the potential pesticide groundwater contamination on different weather conditions. Numerical results will be presented with pesticides atrazine and lindane in a soil profile with 20°C constant temperature, minimum and maximum surface temperatures varying and spreading in the soil profile between )5 and 30°C and between 15 and 45°C.
The region of Ribeirão Preto City, southeastern Brazil,
is an important sugar cane and recharge a... more The region of Ribeirão Preto City, southeastern Brazil,
is an important sugar cane and recharge area for groundwater of the Guarany aquifer. This research was conducted to evaluate the potential contamination of groundwater with nitrates in the area and in surrounding municipal wells. No significant amount of nitrate was found in the recharge agricultural area. However, nitrate levels
were detected at concentrations higher than the Maximum Concentration Level (MCL) of 6.0 mg/L in a downtown, urban, well located away from agriculture, which had no history of nitrogen application, reaching values higher than the maximum risk coefficient for infants (RC) of 1.0.
Spanish Journal of Agricultural Research, 2007
Ciência Rural, 2015
Sugarcane is an important crop for sugar and biofuel production in Brazil. Growers depend greatly... more Sugarcane is an important crop for sugar and biofuel production in Brazil. Growers depend greatly on herbicides to produce it. This experiment used herbicide physical-chemical and sugarcane plant physiological properties to simulate herbicide uptake and estimate the bioconcentration factor (BCF). The (BCF) was calculated for the steady state chemical equilibrium between the plant herbicide concentration and soil solution. Plantwater partition coefficient (sugarcane bagasse-water partition coefficient), herbicide dilution rate, metabolism and dissipation in the soil-plant system, as well as total plant biomass factors were used. In addition, we added Tebuthiuron at rate of 5.0kg a.i. ha -1 to physically test the model. In conclusion, the model showed the following ranking of herbicide uptake: sulfentrazone > picloram >tebuthiuron > hexazinone > metribuzin > simazine > ametryn > diuron > clomazone > acetochlor. Furthermore, the highest BCF herbicides showed higher Groundwater Ubiquity Score (GUS) index indicating high leaching potential. We did not find tebuthiuron in plants after three months of herbicide application.
Pesticidas: Revista de Ecotoxicologia e Meio Ambiente, 2010
Acid phosphatases play important roles in algae metabolism such availability/recycling of inorgan... more Acid phosphatases play important roles in algae metabolism such availability/recycling of inorganic phosphate and autophagic digestive processes. Chemicals released into the environment from agricultural activities and through industrial and urban wastes, may impair algae enzyme activity. The aim of this work was to evaluate the in vitro activation/ inhibition effect of ten metals, commonly present as contaminants in soil and water, on the acid phosphatase extracted from the green algae Pseudokirchneriella subcapitata. Results demonstrated that Hg, Al, Mo, Pb, Se and Cd inhibited the enzyme activity in 56.3, 54.5, 30.6, 25.5, 23.1 and 11.5%, respectively. This corresponds to the maximum percentage of effect attained at the metal concentrations tested (0.02-2.0 mM). On the other hand, Cu, Zn, Ni and Cr exhibited an increment on phosphatase activity equal to 95.5, 87.6, 77.6 and 42.8%, respectively. Kinetic parameters values were calculated for the metals that showed highest effects. Thus, Ki (inhibition constant) and Kd (dissociation constant) values equal to 0.0400 and 0.0016 mM were determined for Hg and Cu, respectively. A noncompetitive inhibition mechanism was attributed to the former. Results improved the understanding of the basic events of the impact of metals at biochemical levels in primary producers organisms.
Pesticidas: Revista de Ecotoxicologia e Meio Ambiente, 2014
Otimizou-se um método analítico para a determinação de multirresíduos de organoclorados em camarã... more Otimizou-se um método analítico para a determinação de multirresíduos de organoclorados em camarão marinho para a espécie Litopenaeus vannamei e em músculo de peixes da espécie Oreochromis sp., chamada popularmente de tilápia-vermelha. Utilizou-se a técnica de extração denominada QuEChERS, empregando cromatografi a a gás com detector de micro captura de elétrons (CG-μECD) para análise dos seguintes organoclorados em amostras de camarão e em músculo de peixes: hexaclorobenzeno, lindano, DDE, DDT, clorpirifós, endossulfan sulfato, endossulfan beta, endossulfan alfa, heptacloro, aldrin, endrin e dieldrin. O limite de detecção para todos os compostos foi de 0,0005 μg•g -1 e o limite de quantifi cação do método foi estabelecido em 0,005 μg•g -1 . Os valores de recuperação variaram entre 80 % e 120 % com desvio padrão (RSD) abaixo de 20 % para todos os compostos.
Science of The Total Environment, 2010
This study presents a model to simulate the organic substance concentrations in corn grains assum... more This study presents a model to simulate the organic substance concentrations in corn grains assuming that the substances in soil solution are absorbed via the transpiration stream by plants growing in soils fertilized with sewage sludge (SS). The model was applied and validated using soil and corn grain samples from a long-term field experiment with six successive yearly applications of SS to the soil. The following polycyclic aromatic hydrocarbons (PAHs) were simulated and evaluated in soil and grain samples: acenaphthene, acenaphthylene, anthracene, benz(a)anthracene, benz(a)pyrene, benz(b)fluoranthene, benz(g,h,i)perylene, benz(k)fluoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, fluorene, indeno(1,2,3-c,d)pyrene, naphthalene, phenanthrene and pyrene. The PAH bioconcentration factors (BCF) in corn grains ranged from 1.57 to 10.97 L kg(-1). Polycyclic aromatic hydrocarbons with low soil distribution coefficients and high values of transpiration stream concentration factors (TSCF) are more likely to be absorbed by corn plants and accumulated in grains. It was possible to estimate and observe that highly lipophilic PAH molecules (heavy PAHs) show lower accumulative potential in corn grains than the less lipophilic ones (light PAHs). Sewage sludges containing significant concentrations of light PAHs with two, three or four benzene rings should be avoided as fertilizers in alimentary field crops.
Pesticidas: Revista de Ecotoxicologia e Meio Ambiente, 2009
* Pesquisador, Ph.D. em Fisiologia Vegetal, Embrapa Meio Ambiente, Jaguariúna, SP, Brasil (e-mail... more * Pesquisador, Ph.D. em Fisiologia Vegetal, Embrapa Meio Ambiente, Jaguariúna, SP, Brasil (e-mail: [email protected]). ** Pesquisador, Ph.D. em Matemática, Embrapa Meio Ambiente, Jaguariúna, SP, (e-mail: lourival@ cnpma.embrapa.br; spadotto@cnpma. ...
Scientia Agricola, 2002
propriedades fungicidas, é muito utilizado na região Nordeste do Brasil em áreas de produção de f... more propriedades fungicidas, é muito utilizado na região Nordeste do Brasil em áreas de produção de frutíferas. Este composto pode permanecer estável por vários meses após sua aplicação no solo, sendo sua meia vida na água superior a três semanas. Corpos de água superficiais nas proximidades das culturas são portanto susceptíveis de serem contaminados pelo paclobutrazol, com o risco de promover efeitos adversos para a fauna aquática e para a saúde humana. No presente trabalho foi estudada a bioconcentração e algumas alterações bioquímicas, medidas pela atividade das enzimas transaminase glutâmico-oxalacética (TGO), lactato desidrogenase (LDH) e glutationa Stransferase (GST) em tecidos do peixe pacú prata (Metynnis argenteus), exposto ao paclobutrazol durante 28 dias. O paclobutrazol aumentou a atividade de LDH e GST no fígado para as concentrações de 3 mg L -1 (28 o dia de exposição) e 30 mg L -1 (7 o dia de exposição), respectivamente. No 28 o dia, a concentração de paclobutrazol no músculo atingiu níveis residuais de 166 mg kg -1 para a concentração média determinada na água de 2,7 mg L -1 , estimando-se um fator de bioconcentração (FBC) para a situação de equilíbrio equivalente a 73. A medida da atividade de LDH e GST pode ser utilizada como biomarcador de exposição ao paclobutrazol. Esta exposição deve estar em situações extremas para proporcionar risco significativo em humanos que se alimentam de peixes contendo resíduos do agroquímico. Palavras-chave: bioconcentração, peixe, toxicidade
Spanish Journal of Agricultural Research, 2014
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Papers by Lourival C Paraiba
is an important sugar cane and recharge area for groundwater of the Guarany aquifer. This research was conducted to evaluate the potential contamination of groundwater with nitrates in the area and in surrounding municipal wells. No significant amount of nitrate was found in the recharge agricultural area. However, nitrate levels
were detected at concentrations higher than the Maximum Concentration Level (MCL) of 6.0 mg/L in a downtown, urban, well located away from agriculture, which had no history of nitrogen application, reaching values higher than the maximum risk coefficient for infants (RC) of 1.0.
is an important sugar cane and recharge area for groundwater of the Guarany aquifer. This research was conducted to evaluate the potential contamination of groundwater with nitrates in the area and in surrounding municipal wells. No significant amount of nitrate was found in the recharge agricultural area. However, nitrate levels
were detected at concentrations higher than the Maximum Concentration Level (MCL) of 6.0 mg/L in a downtown, urban, well located away from agriculture, which had no history of nitrogen application, reaching values higher than the maximum risk coefficient for infants (RC) of 1.0.