Influência da granulometria e taxas de filtração no tratamento de água utilizando dupla filtração

The contamination of water sources of public drinking by waste originated by anthropogenic activities has brought various risks to human health. Among the consequences of such activities can highlight the bloom of microalgae and cyanobacteria, which have the potential to produce toxins dangerous to humans, and the presence of humic substances that are generated by the decomposition of natural organic matter (NOM), such as vegetation. When found in water sources for public supply, present negative aspects conferring high color, odor and taste. The double filtration technology has good efficiency in water with the presence of cyanobacteria and different quality variations. Therefore, this study aimed to evaluate the behavior of the technique of double filtration with pre-oxidation for water purifiers the lagoon of Extremoz-RN, which currently has high concentrations of cyanobacteria. The research is summarized in four phases: the first phase turned to static tests in jarteste equipment in the laboratory and subsequent phases were tested in the Pilot Plant of Double Filtration. For the second and third stage filtration rates were tested filtration rates of 120 and 180 m3 / m2 .day for ascending boulders filters and 160 and 240 m3 / m2 .day in the filters in quick sand descendants. The last phase aimed to evaluate the double filtration with pre-oxidation. The results demonstrated that the system could produce double filtration in all trials of good quality water according to the Decree nº. 2914/11 of the Ministry of Health. The use of preoxidation favored the removal of microcystin and color at the end of the tests, reaching a percentage of color removal around 60%. The analysis of variance in the data, enabled prove that the filtration rates of 180 m3 / m2.d the gravel filter and 240 m3 /m2 .d in rapid filters, were the most significant for the removal of turbidity. The ascending filter of boulder 4 with particle size finer filter layer showed the best performance and the best means of turbidity and apparent color. The rapid filter downward 1 was more efficient in removing turbidity reaching removal about 100%

Caracterização e aplicação de vermicultura natural e quimicamente modificada na adsorção de azul de metileno

Chemical modification of clays has been extremely studied in the search for improvements of their properties for use in various areas, such as in combating pollution by industrial effluents and dyes. In this work, the vermiculite was chemically modified in two ways, characterized and evaluated the adsorption of methylene blue dye. First was changed with the addition of a surfactant (hexadecyltrimethylammonium bromide, BHTA) making it an organophilic clay and then by adding an acid (HCl) by acid activation. Some analyzes were performed as X-ray fluorescence (FRX), X-ray diffraction (DRX), adsorption isotherms of methylene blue dye, infrared (FTIR) , scanning electron microscopy (SEM), thermal gravimetric analysis and spectroscopy energy dispersive (EDS). Analysis by FRX of natural vermiculite indicates that addition of silicon and aluminum, clay presents in its structure the magnesium, calcium and potassium with 16 % organic matter cations. The DRX analyzes indicated that the organic vermiculite was an insertion of the surfactant in the space between the lamellae, vermiculite and acid partial destruction of the structure with loss of crystallinity. The adsorption isotherms of methylene blue showed that there was a significant improvement in the removal of dye to the vermiculite with the addition of cationic surfactant hexadecyltrimethylammonium bromide and treatment with acid using HCl 2 mol/L. In acid vermiculites subsequently treated with surfactant, the adsorption capacity increased with respect to natural vermiculite, however was much lower compared vermiculite modified with acid and surfactant separately. Only the acidic vermiculite treated with surfactant adjusted to the Langmuir model. As in the infrared spectrometry proved the characteristics of natural vermiculite. In the organic vermiculite was observed the appearance of characteristic bands of CH3, CH2, and (CH3)4N. Already on acid vermiculite, it was realized a partial destruction with decreasing intensity of the characteristic band of vermiculite that is between 1074 and 952 cm-1. In the SEM analysis, it was observed that there was partial destruction to the acid treatment and a cluster is noted between the blades caused by the presence of the surfactant. The TG shows that the higher mass loss occurs at the beginning of the heating caused by the elimination of water absorbed on the surface between layers. In the organic vermiculite also observed a loss of mass between 150 and 300 °C caused decomposition of the alkylammonium molecules (surfactants)

Alteração da qualidade do solo em zona ripária sob diferentes usos: potencial de poluição para um manancial tropical

The demographic growth press environments that are more susceptible to perturbations, like riparian areas, without knowing about the effects of replacing these natural environments by different land uses on soil quality and, consequently, on watershed. The study of soil quality has evolved as an important tool for soil sustainable management of this component of the biosphere that affects aquatic and terrestrial ecosystems functions. Thus, physical and chemical soil proprieties were measured to assess soil quality under different land uses (agricultural, pasture, urban, industrial and natural vegetation,) in the riparian zone of Extremoz Lake, an important human water source, evaluating whether the soil offers potential risk to water pollution. Data were subjected to descriptive statistics and Principal Component Analysis (PCA). The results showed negative changes in soil quality such as alkalinization and increase in P, Pb, Mn and Zn contents in most anthropized areas. The sandy texture and low organic matter content in all soils showed the fragility of the soil to erosion and leaching of elements in excess to water bodies, evidencing that this soils has potential to diffuse contaminants. Conservative management of soil is necessary to provide an adequate ecological state in riparian zones of the Extremoz Lake, thus allowing controlling and buffering diffuse sources of pollution to this important water supply source

Influência de atividades antrópicas sobre a salinização da água em área de dunas no Município de Guamaré RN

The municipality of Guamaré is located on the north coast of RN, Salineira zone, with a land area of 259 km2 and a population of approximately 12,500 inhabitants (IBGE, 2010). Presents strong morphological instability caused mainly by the influence of human activities in the region. The present study aims to assess the existing levels of salts in the springs of the region, by evaluating the electrical conductivity, pH, salinity, chlorides, hardness, calcium, magnesium and heavy metals in the water. The collection and analysis methods adopted in the survey are based on APHA (2005). The electrical conductivity, salinity and chloride behaved similarly throughout the study. Some points suffered the direct effect of the salt ponds and others. Given the existence of a drainage ditch between the saline and monitored region, there was little change in the environment, including the native vegetation. The opposite situation occurred in farms where the region is fully committed local vegetation and water holes and wells used in the past for domestic use are practically disabled (high salt content). In Rio Miassaba formation of an estuary is reversed, with the farther out from the sea showing higher salt concentracions, which may be associated with the discharge of organic matter and natural evaporation rate. In periods of no rainfall had a few points higher than the levels of salts found in seawater and may be associated with high evaporation in the region. Detected a positive factor is the high resilience and reducing salt, after periods of rainfall incidence

Aplicação da parafina e do óleo de linhaça como hidrofobizantes da vermiculita, para remoção de derivados de óleo diesel resentes em água produzida sintética

Produced water has lately aroused interest due to their high degree of salinity, suspended oil particles, chemicals added in various manufacturing processes, heavy metals and radioactivity sometimes. Along with oil and due to its high volume production, water production is one of the pollutants of most concern in the process of oil extraction. PAHs due to their ubiquity and their characteristics carcinogenic or mutagenic and teratogenic even have attracted the attention of every scientific society. Formed from the incomplete combustion of organic matter may be natural or anthropogenic. Some materials have been researched with the goal of cleaning up environmental matrices that may be contaminated by hydrocarbons. Among these materials researched various clays have been employed, of which highlights the vermiculite. The family of phyllosilicates, vermiculite for its potential and its high hydrophobic surface area has been a tool widely used in the decontamination of water in processes of oil spills. However, when it loses its capacity expanded hydrophobic having the necessity of using a hidrofobizante to make it organophilic. Among the numerous hidrofobizantes researched and used the linseed oil was the pioneer. In this study sought to evaluate the capacity of removal of PAHs using the vermiculite hydrofobized with linseed oil and wax also, for it was made use of the 24 full factorial design as the main tool for the experiments. We also evaluated the clay grain size (-20 +48 and -48 +80 #), the percentage of hidrofobizante applied (5 and 10%) and salinity of the water produced synthesized in our laboratory (35,000 and 55,000 ppm). The molecular fluorescence spectroscopy due to its sensitivity and speed was used to verify the adsorption capacity of clay, as well as gas chromatography served as an auxiliary technique to identify and quantify the PAHs in solution. In order to characterize the vermiculite was made use of X-ray fluorescence and X-ray diffraction. The infrared and thermogravimetry were essential to note hydrophobization and the amount of coating of clay. According to the fluorescence analysis showed that the test 12 was the best result in about 98% adsorption of fluorescent compounds, however the high salinity, the smallest particle size, the highest percentage of hidrofobizante and the use of linseed oil showed greater efficiency in the removal capacity of these hydrocarbons, in accordance with the trend followed by the analysis of the major factors of the factorial design. To verify the adsorption capacity of clay using a fixed volume of water produced synthetically, used as the test base 12, at their respective levels and factors. Thus, it was observed that after adding about 1 ½ liters of water solution produced synthetically, about 300 times its volume in mass, the vermiculite was able to adsorb 80% of fluorescent species present in solution

Hidrocarbonetos policíclicos aromáticos no meio ambiente: diferenciação de fontes em sedimentos e metabólitos em bile de peixes

Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirect atmospheric deposition. Sources of naturally occurring PAHs include natural fires, natural oil seepage and recent biological or diagenetic processes. Anthropogenic sources of PAHs, acute or chronic, are combustion of organic matter (petroleum, coal, wood), waste and releases/spills of petroleum and derivatives (river runoff, sewage outfalls, maritime transport, pipelines). Besides the co-existence of multiples sources of PAH in the environmental samples, these compounds are subject to many processes that lead to geochemical fates (physical-chemical transformation, biodegradation and photo-oxidation), which leads to an alteration of their composition. All these facts make the identification of the hydrocarbons sources, if petrogenic, pyrolytic or natural, a challenge. One of the objectives of this study is to establish tools to identify the origin of hydrocarbons in environmental samples. PAH diagnostic ratios and PAH principal component analysis were tested on a critical area: Guanabara Bay sediments. Guanabara Bay is located in a complex urban area of Rio de Janeiro with a high anthropogenic influence, being an endpoint of chronic pollution from the Greater Rio and it was the scenario of an acute event of oil release in January 2000. It were quantified 38 compounds, parental and alkylated PAH, in 21 sediment samples collected in two surveys: 2000 and 2003. The PAH levels varied from 400 to 58439 ng g-1. Both tested techniques for origin identification of hydrocarbons have shown their applicability, being able to discriminate the PAH sources for the majority of the samples analysed. The bay sediments were separated into two big clusters: sediments with a clear pattern of petrogenic introduction of hydrocarbons (from intertidal area) and sediments with combustion characteristics (from subtidal region). Only a minority of the samples could not display a clear contribution of petrogenic or pyrolytic input. The diagnostic ratios that have exhibited high ability to distinguish combustion- and petroleum-derived PAH inputs for Guanabara Bay sediments were Phenanthrene+Anthracene/(Phenanthrene+Anthracene+C1Phenanthrene); Fluorantene/(Fluorantene+Pyrene); Σ (other 3-6 ring PAHs)/ Σ (5 alkylated PAH series). The PCA results prooved to be a useful tool for PAH source identification in the environment, corroborating the diagnostic indexes. In relation to the temporal evaluation carried out in this study, it was not verified significant changes on the class of predominant source of the samples. This result indicates that the hydrocarbons present in the Guanabara Bay sediments are mainly related to the long-term anthropogenic input and not directly related to acute events such as the oil spill of January 2000. This findings were similar to various international estuarine sites. Finally, this work had a complementary objective of evaluating the level of hydrocarbons exposure of the aquatic organisms of Guanabara Bay. It was a preliminary study in which a quantification of 12 individual biliar metabolites of PAH was performed in four demersal fish representing three different families. The analysed metabolites were 1-hydroxynaphtalene, 2-hidroxinaphtalene, 1hydroxyphenanthrene, 9-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1hydroxypyrene, 3-hidroxibiphenil, 3- hydroxyphenanthrene, 1-hydroxychrysene, 9hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxybenz(a)pyrene. The metabolites concentrations were found to be high, ranging from 13 to 177 µg g-1, however they were similar to worldwide regions under high anthropogenic input. Besides the metabolites established by the used protocol, it was possible to verified high concentrations of three other compounds not yet reported in the literature. They were related to pyrolytic PAH contribution to Guanabara Bay aquatic biota: 1-hydroxypyrine and 3-hydroxybenz(a)pyrine isomers

Colêmbolos (arthropoda: hexapoda: collembola) numa área de caatinga do nordeste brasileiro

Edaphic ecosystems are the basis for the production of terrestrial biological resources and their dynamics affect not only the natural environment but also society and their economic activities. In Caatinga biome, the semi-arid climate associated with an inadequate soil management has increased the degradation and loss of productive potential of the soil. In this context, the study of soil fauna, including springtails, becomes an important indicator of soil quality. This study aimed to evaluate the fauna of Collembola in an area of Caatinga of Rio Grande do Norte State and the influence of biotic and abiotic factors, such as soil, vegetation and climate characteristics, on the structure of the taxocenosis. The environmental variables which were used were the following ones: granulometry (represented by the proportion of sand), quantity of organic matter and soil pH, richness, density and aerial biomass of the vegetal structure, and necromass. We used pitfall traps intending to collect specimens of the epiedaphic fauna of Collembola in 30 points located on Cauaçu Farm, João Câmara, RN, in July (rainy season) and November (dry season) 2011. We collected 5513 individuals of 15 species distributed in 13 genera and 9 families of Collembola. Five of the recorded species are new to science, confirming the expected high degree of endemism for Caatinga biome, and the highest abundance was recorded in the rainy season, which suggests Collembola sensitivity to low humidity. Four species were more abundant in the dry season, all of them belonged to the Order Entomobryomorpha. Results of statistical analyzes suggest that plant species richness, aerial biomass of vegetal structure, proportion of sand in the soil, pH and humidity are the main influences to the abundance of Collembola in the region studied