Filossilicatos: efeitos no crescimento e na nutri����o de plantas de milho e no teor de sil��cio do solo

Importance of silicon fertilization is related to the benefits that silicon is able to promote tolerance to heavy metals, reduce the incidence of pests and diseases, increased productivity, drought tolerance, among others. The objective of this study was to evaluate the phyllosilicates effect on biomass formation, nutrients and silicon on the early stages of corn plants compared to wollastonite. Experiment was installed and conducted in a greenhouse located at the Universidade Estadual Paulista, UNESP, in Registro, SP. Consisting of 10 treatments established in a randomized block design in scheme factorial (2 x 5), with five replications. First factor corresponds to the two types of soil (Oxisol and Ultisol) and the second factor, five treatments (control, 0 kg ha-1 Si; wollastonite W13, 13 kg ha-1 Si; wollastonite W26, 26 kg ha-1 Si; phyllosilicates F13, 13 kg ha-1 Si; phyllosilicates F26, 26 kg ha-1 Si). In Ultisol, phyllosilicates increased production of fresh, dry biomass and silicon content in shoots of corn compared to treatment with wollastonite and control. Highest Si content compared to control (6.2 g kg-1) was obtained with 13 kg ha-1 Si of phyllosilicates (9.8 g kg-1). The greatest accumulation mass and Si in plants by applying phyllosilicates were observed in Ultisol, although this display Si content higher than Oxisol.

Efeitos da exposi����o gestacional a c��dmio e dimetoato sobre o comportamento de ansiedade na prole de ratos

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Comportamento materno e c��ncer de bexiga urin��ria: implica����es da modula����o de eixos hormonais e receptores de esteroides na fisiopatologia de les��es neopl��sicas

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Selenium and sulfur: mitigation in plant stresses

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Selenium and sulfur: mitigation in plant stresses

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Availability of heavy metals in contaminated soil evidenced by chemical extractants

Heavy metals have been accumulating in Brazilian soils, due to natural processes, such as atmospheric deposition, or human industrial activities. For certain heavy metals, when in high concentrations in the soil, there is no specific extractant to determine the availability of these elements in the soil. The objective of the present study was to evaluate the availability of Cd, Cu, Fe, Mn, Pb and Zn for rice and soybeans, using different chemical extractants. In this study we used seven soil samples with different levels of contamination, in completely randomized experimental design with four replications. We determined the available concentrations of Cd, Cu, Fe, Mn, Pb and Zn extracted by Mehlich-1, HCl 0.1 mol L-1, DTPA, and organic acid extractants and the contents in rice and soybeans, which extracts were analyzed by ICP-OES. It was observed that Mehlich-1, HCl 0.1 mol L-1 and DTPA extractants were effective to assess the availability of Cd, Cu, Pb and Zn for rice and soybeans. However, the same was not observed for the organic acid extractant.

Aspectos t��cnicos e ambientais da incinera����o de res��duos s��lidos urbanos: considera����es sobre a proposta para S��o Paulo

A tecnologia de incinera����o no gerenciamento de res��duos s��lidos urbanos �� empregada de maneira intensa em diversos pa��ses do mundo. No Brasil, al��m da sua utiliza����o eventual em res��duos de servi��os de sa��de, h�� uma proposta para implanta����o de duas usinas de grande porte visando ao tratamento t��rmico de res��duos s��lidos domiciliares na cidade de S��o Paulo. Atrav��s de uma revis��o bibliogr��fica sobre o tema, s��o apresentados os principais par��metros t��cnicos e ambientais desta tecnologia, entre eles os mecanismos de combust��o e de forma����o de poluentes, os tipos de equipamentos empregados, as formas de manejo e disposi����o de cinzas e esc��rias e os m��todos de controle e redu����o de emiss��es atmosf��ricas como gases ��cidos, material particulado e metais pesados. Tamb��m �� feita uma revis��o do atual conhecimento t��cnico-cient��fico sobre dioxinas e furanos relativamente �� incinera����o de res��duos s��lidos urbanos. A partir desta base te��rica pesquisada e da an��lise dos Estudos de Impacto Ambiental e dos Relat��rios de Impacto Ambiental das usinas de incinera����o de Santo Amaro e Sapopemba, conclui-se que tais incineradores, na forma como s��o propostos, n��o apresentam o n��vel tecnol��gico necess��rio para atender ��s normas de opera����o e emiss��o de poluentes vigentes em pa��ses onde h�� legisla����o regulando esta atividade.

Estudo de equil��brio e cin��tica da biossor����o de cobre (II) por Rhizopus Microsporus.

A polui����o relacionada a metais pesados tem recebido uma aten����o especial devido a sua alta toxicidade, n��o biodegradabilidade e tend��ncia de acumular-se na cadeia alimentar. Apesar disso, metais pesados tamb��m s��o considerados recursos valiosos, portanto a sua remo����o em conjunto com a sua recupera����o torna-se ainda mais importante. Este caso aplica-se aos rejeitos de minera����o de cobre, os quais oferecem a possibilidade de recupera����o do metal e de sua conten����o de maneira segura do meio ambiente. Tais rejeitos se caracterizam por ocuparem enormes ��reas inundadas e abrigarem solu����es dilu��das de cobre (II), por��m, muitas vezes, acima dos limites seguros. Diversos processos tradicionais de tratamento mostram-se dispon��veis para remover o cobre de tais solu����es, no entanto, em certas aplica����es eles podem ser ineficientes ou muito onerosos. Nesse contexto, a biossor����o �� uma alternativa interessante. Nesse processo, certos microrganismos, como fungos, bact��rias e algas, ligam-se passivamente ao cobre na forma ��ons ou outras mol��culas em solu����es. No presente trabalho foi avaliado o potencial de biossor����o de ��ons cobre (II) pela biomassa do fungo Rhizopus microsporus, coletado e isolado da ��rea de rejeitos da Mina do Sossego, na regi��o norte do Brasil. Isotermas de biossor����o foram determinadas experimentalmente em bateladas sob temperatura de 25��C, agita����o de 150 rpm, concentra����o de biomassa de 2,0 a 2,5 g/L e tempo de contato m��nimo de 4 horas. O pH mostrou ser um fator importante no equil��brio da biossor����o, sendo o valor m��ximo da capacidade de biossor����o de 33,12 mg de cobre / g biomassa encontrado em pH 6. Valores sucessivamente menores s��o encontrados pela acidifica����o da solu����o, sendo o pH 1 considerado adequado para o processo de dessor����o, correspondendo a uma capacidade de biossor����o de 1,95 mg/g. Modelos de adsor����o de Langmuir e de Freundlich ajustaram-se adequadamente ��s isotermas tanto com pH controlado quanto n��o controlado. Foi constatado que a troca i��nica �� um dos mecanismos envolvidos na biossor����o do cobre com Rhizopus microsporus. Tanto o modelo de pseudo-primeira ordem quanto o de pseudo-segunda ordem ajustaram-se aos dados cin��ticos da biossor����o, sendo que o equil��brio ocorre em aproximadamente 4 horas. A biomassa conservou a capacidade de biossor����o ao operar repetidamente em tr��s ciclos de sor����o-dessor����o. A biomassa vi��vel e a morta n��o apresentaram diferen��a estatisticamente significativa na capacidade de biossor����o.

Avalia����o da remo����o de mat��ria org��nica e nutrientes por sor����o em solos residuais

A recarga artificial de aqu��feros (RAQ) com ��guas residuais tratadas (ART) �� uma pr��tica que pode contribuir para a reposi����o de volumes de ��gua no solo, que pode ser muito vantajoso em ��reas com d��ficit h��drico ou com sobre-explora����o de ��guas subterr��neas. No entanto, as cargas residuais das ART (p.e. mat��ria org��nica, nutrientes, metais pesados e microrganismos patog��nicos) podem constituir uma desvantagem para a qualidade da ��gua subterr��nea, se o solo apresentar condi����es desfavor��veis para a sua infiltra����o. Realizaram-se ensaios laboratoriais em batelada para avaliar a remo����o de mat��ria org��nica e nutrientes (formas de nitrog��nio e f��sforo) na componente fina de um solo residual gran��tico, proveniente de uma zona previamente selecionada para a infiltra����o de ART, localizada no nordeste da regi��o da Beira Interior (Quinta de Gon��alo Martins, Guarda, Portugal). Os resultados dos ensaios de sor����o em batelada mostram uma boa remo����o de P-PO4, por complexa����o e precipita����o, o que indica que o solo apresenta capacidade reativa para remover a carga residual de fosfato das ART. Ap��s realiza����o dos ensaios em batelada, as propriedades do solo mantiveram-se praticamente inalteradas.

Qualidade do solo da camada de cobertura final em ��rea de disposi����o de res��duos no semi��rido tropical

The final disposal of municipal solid waste in unsuitable areas without an infrastructure that meets the health measures and environmental protection, coupled with the lack of technical criteria in phase and decommissioning of the dump can promote environmental degradation. Alternatively to minimize the impacts of this activity for the stabilization of the area by isolating the massive waste with implementation of an adequate and finished by a layer of soil for plant growth final cover system. In this context, the present study aimed to evaluate the quality of the final cover in the area of a disabled dump the tropical semi-arid region in order to assist the process of recovery of these areas. The study area is located in the tropical semi-arid region in S��o Jo��o do Sabugi /RN. Soil samples were collected in the dump area and bushland as a benchmark of quality. To which they were subjected to analysis of physical attributes (particle density, bulk density, grain size and porosity), chemical properties (pH, K + , Na+ , Ca2 + , Mg2 + and Al3 + exchangeable, potential acidity, available phosphorus, sum of bases, CEC, base saturation, aluminum saturation, saturation Na + and adsorption ratio sodium, total organic carbon and total nitrogen) and total and soluble concentrations of heavy metals (Mn, Pb, Zn, Cd, Cu, Mo, Co, Cr, Ba and Ni). The differences between physical and chemical soil under native forest and final cover showing reduction of soil quality in the area off to the dump, which hinders the development of native vegetation and the recovery of the area. The absence of superior waterproofing to allow vertical transfer between the solid waste and the final cover promoted enrichment by chemical elements and heavy metals in excess can impair revegetation. Deficiencies found in the construction process of the final cover point to the need for intervention to accelerate the process of stabilization and recovery of the area of the local ecosystem

Estudo da incorpora����o de res��duos de perfura����o para aplica����o em cimenta����o de po��os de petr��leo

During the drilling of oil and natural gas are generated solid waste, liquid and gaseous. These solid fragments, which are known as cuttings, are carried to the surface through the drilling fluid. Furthermore, this fluid serves to cool the bit, keeping the internal pressure of the well, and others. This solid residue is very polluting, because it has incorporated beyond the drilling fluid, which has several chemical additives harmful to the environment, some heavy metals that are harmful to the environment, such as lead. To minimize the residue generated, are currently being studied numerous techniques to mitigate the problems that such waste can cause to the environment, like addition of cuttings in the composition of soil cement brick masonry construction, addition of cuttings on the clay matrix for the manufacture of solid masonry bricks and ceramic blocks and coprocessing of the cuttings in cement. So, the main objective of this work is the incorporation of cuttings drilling of oil wells, the cement slurry used in the cementing operation of the well. This cuttings used in this study, arising from the formation Pend��ncias, was milled and separated in a sieve of 100 mesh. After grinding had a mean particle sike in order of 86 mm and crystal structure containing phases of quartz and calcite type, characteristic of the Portland cement. Were formulated and prepared slurries of cement with density 13 lb / gal, containing different concentrations of gravel, and realized characterization tests API SPEC 10A and RP 10B. Free water tests showed values lower than 5.9% and the rheological model that best described the behavior of the mixtures was the power. The results of compressive strength (10.3 MPa) and stability (Dr <0.5 lb / gal) had values within the set of operational procedures. Thus, the gravel from the drilling operation, may be used as binders in addition to Portland cement oil wells, in order to reuse this waste and reduce the cost of the cement paste.

Influ��ncia da radia����o ionizante natural no a��ude do boqueir��o (RN): avalia����o de risco sa��de/ambiente

The contamination of water bodies with toxic substances causes a decrease in water quality, representing a risk to public health. In this context, human activities are generally seen as the main sources of water degradation. However, elements found naturally in the environment can also compromise water quality. Thus, the Boqueir��o���s dam, located in the municipality of Parelhas (RN, Brazil), was chosen as area for the development of this study, as its geological region is rich in the emission of natural ionizing radiation that produces byproducts like lead and Radon. Moreover, the area has a strong human influence that enhances the risks of pollutant discharge in this body of water.Thus, the objectives of this study were centered (i) in the analysis of risk perception in the city of Parelhas (RN/Brasil) due to the use of the water from the Boqueir��o Dam; and (ii) in the assessment of water quality in the Dam using methods that quantify, mainly, heavy metals and radiation levels, as well as these toxics potential of inducing mutations on genetic material. The analysis of risk perception showed that the population in the city of Parelhas can perceive a risk in using the water from the dam and that they can recognize factors that influence the water quality. Regarding the second objective, the set of data point to the contamination of the Dam by heavy metals, as well as levels of radioactive parcicles and Radon ��� also present in high concentrations in outdoor air and on soil. Thus, it is possible to infer that the population residing in this area is subjected to injuries caused by exposure to natural and anthropogenic contamination. Our findings corroborate with the perception of the population regarding the risks associated with the use of the Dam for several types of activities. It is expected that the information gathered in this study can substantiate activities and future researches in this semiarid region in the Rio Grande do Norte/Brazil. Also, that the set of data can enable a better understanding of the specific toxicological scenario of risk found for the population and the effect of the contamination for the biota, which aids the development of a future risk assessment and a consequent management of this local issue.

Constru����o de bibliotecas de cDNAs subtra��dos a partir das sementes de Mamona submetidas �� estresse h��drico e an��lise in silico de transcritos potencialmente expressos sob condi����es de estresse: Metalotioneina, prote��na reprimida por auxina de 12.5 kDa e Glutelina tipo-A3

Estresses ambientais abi��ticos s��o fatores que causam respostas ao n��vel molecular, fisiol��gico e morfol��gico em plantas, dependendo tamb��m de sua intensidade e dura����o. �� visto que algumas esp��cies apresentam toler��ncia a condi����es estressantes e ao mesmo tempo s��o fontes naturais de mat��ria prima para ind��stria. Nesse contexto encontra-se a mamona (Ricinus comunnis L.), principal fonte de ��leo de r��cino valorizado por suas aplica����es farmac��uticas e principalmente industriais, vem sendo usada como cultura em regi��es onde a disponibilidade de ��gua �� reduzida, usada como fonte de renda para agricultura da regi��o nordeste brasileira. Visto que pouco se sabe sobre as respostas moleculares que levam essa planta a tolerar regi��es secas e como as sementes, principais foco de interesse, respondem a essa escassez, nesse trabalho foram constru��das duas bibliotecas de cDNAs, onde a partir de uma abordagem subtrativa, continham RNAs diferencialmente expressos em sementes de plantas mamona submetidas ao estresse h��drico durante 5 dias (biblioteca L7), e a outra RNAs diferencialmente expressos em sementes controle (biblioteca L5). A biblioteca L7 apresentou a maior variedade de transcritos com um total de 182. A maior parte das fun����es estabelecidas pelo sistema Gene Ontology - GO, foram direcionadas aos ���Processos Metab��licos��� (526), em segundo ���Respostas a est��mulos��� (57), o terceiro termo mais abundante foram referentes a ���Desenvolvimento���(26). J�� na biblioteca L5, foram encontrados 91 transcritos, com maior parte de suas fun����es referentes a ���Processos Metab��licos���(413), em segundo ���Respostas a est��mulos��� (8) e em terceiro Regula����o (6). Alguns dos transcritos da biblioteca L7 foram escolhidos para an��lise por repetirem-se mais de 3x e n��o aparecerem na biblioteca L5, o que indica uma poss��vel regula����o positiva sobre estresse. As an��lises sobre Metalotione��na (4x), mostraram que a sequ��ncia de proteica apresentava os dom��nios conservados que a caracterizava como tipo II, onde s��o encontrados dois dom��nios funcionais ricos em ciste��na com posi����es altamente conservadas, desempenhando a fun����o de ligar-se a metais pesados, correlacionadas assim como a atividade de elimina����o EROs e defesa contra o estresse oxidativo, al��m de apresentar homologia com a sequ��ncia de Bruguiera gymnorhiza, uma planta de mangue adaptada a ambientes salinos. Analisamos tamb��m os transcritos da referente a prote��na AUXIN-REPRESSED 12.5 KDA (3x), apontada como sendo reprimida pelo horm��nio auxina e associada ao processo de dorm��ncia da semente, �� descrito em uma fam��lia g��nica onde v��rios membros pertencem as vias de resposta ao estresse. Por ��ltimo, analisamos a prote��na GLUTELIN TYPE-A 3 (5x), uma importante prote��na de armazenamento com car��ter hidrof��lico, possivelmente direcionada para o vac��olo. Em nosso trabalho foi poss��vel observar um aumento de transcritos em rela����o a subtra����o controle, possivelmente reflexo do aumento do metabolismo da semente, tanto para resposta defensiva ao estresse h��drico quanto para o amadurecimento r��pido da semente onde foram observados transcritos referentes a resposta oxidativa, controle hormonal, prote��nas de reserva e produ����o de ��leo.

Estudo da efici��ncia eletroqu��mica para tratamento de chorume gerado em aterro sanit��rio brasileiro

This work was performing effluent degradation studies by electrochemical treatment. The electrochemical oxidation (EO) hydroquinone (H2Q) was carried out in acid medium, using PbO2 electrode by galvanostatic electrolysis, applying current densities of 10 and 30 mA/cm2 . The concentration of H2Q was monitored by differential pulse voltammetry (DPV). The experimental results showed that the galvanostatic electrolysis process performance significantly depends on the applied current density, achieving removal efficiencies of 100% and 80 % and 10 applying 30 mA/cm2 , respectively. Furthermore, the electroanalytical technique was effective in H2Q be used as a detection method. In order to test the efficiency of PbO2 electrode, the electrochemical treatment was conducted in an actual effluent, leachate from a landfill. The liquid waste leachate (600ml effluent) was treated in a batch electrochemical cell, with or without addition of NaCl by applying 7 mA/cm2 . The efficiency of EO was assessed against the removal of thermo-tolerant coliforms, total organic carbon (TOC), total phosphorus and metals (copper, cobalt, chromium, iron and nickel). These results showed that efficient removal of coliforms was obtained (100%), and was further decrease the concentration of heavy metals by the cathode processes. However, results were not satisfactory TOC, achieving low total removal of dissolved organic load. Because it is considered an effluent complex were developed other tests with this effluent to monitor a larger number of decontamination parameters (Turbidity, Total Solids, Color, Conductivity, Total Organic Carbon (TOC) and metals (barium, chromium, lithium, manganese and Zinc), comparing the efficiency of this type of electrochemical treatment (EO or electrocoagulation) using a flow cell. In this assay was compared to electro streaming. In the case of the OE, Ti/IrO2-TaO5 was used as the anode, however, the electrocoagulation process, aluminum electrodes were used; applying current densities of 10, 20 and 30 mA/cm2 in the presence and absence of NaCl as an electrolyte. The results showed that EO using Ti/IrO2���TaO5 was anode as efficient when Cl- was present in the effluent. In contrast, the electrocoagulation flow reduces the dissolved organic matter in the effluent, under certain experimental conditions.

Caracteriza����o e separa����o f��sica de placas de circuito impresso de computadores obsoletos

The unbridled consumption of electronic equipment associated with fast immersion of new technologies on the market leads to the accelerated growth of electronic waste. Such waste mostly contains printed circuit boards in its structure. Printed circuit boards have many metals, including heavy metals, being highly toxic. Electronic waste is discarded improperly and indiscriminately, usually without any previous treatment and with other municipal waste, contaminating the environment and causing serious problems to human health. Beyond these metals, there are also precious metals and high value-added basis, that can be recovered and recycled, reducing the exploration of natural resources. Thus, due to the high growth potential and reuse of these waste treatment processes, characterization and separation were applied to the printed circuit boards. The printed circuit boards were subjected to physical treatments such as dismantling, crushing, sizing separation, magnetic separation and chemical treatments such as pyrolysis and leaching. Through characterization process (pyrolysis and leaching) the proportions of the components of the granulometric range were determined: 46,08% of metals; 23,32% of polymers and 30,60% of ceramics. It was also observed by particle size separation that metal components tend to concentrate in coarse fractions, while polymeric and ceramic components in fine fractions. From the magnetic separation process was obtained 12,08% of magnetic material and 82,33% of non-magnetic material.