Influência de efluentes têxteis e alimentícios sobre o metabolismo e propriedades físicas e químicas do rio Piauitinga (Sergipe)

Metabolic rates were determined by dissolved oxigen changes in light and dark bottles, filled with river water and after input of mixed effluent concentrations. In another experiment, dissolved inorganic nutrients, chlorophyll-alpha and other physico-chemical parameters were analyzed. Water column showed higher decomposition than production rates. Waste inputs increased primary production rates, but in higher concentrations forced the system to heterotrophy. The natural richness of macrophytes and macroalgae could be limiting the phytoplanktonic production by phosphorus assimilation. Observation of the nitrogenated inorganic nutrients suggest that the natural pelagic system is directed to nitrification. Mixed waste input inverted this trend, toward denitrification.

Teores elevados de Polônio-210 em plantas aquáticas da restinga de Carapebus, RJ

210Po concentrations have been determined in one green alga and in five freshwater plants grown in a pond of the Carapebus restinga (State of Rio de Janeiro). The alga Chara sp showed elevated concentration of 210Po, similar to that observed for marine algae. All the other plants had the lowest concentration of 210Po in the stems and the highest in the roots. Intermediate values were observed in the leaves. The unexpected high concentration of 210Po in the roots, even superior to reported values for roots of plants from high radioactive background areas, must be due to the elevated levels of this radionuclide in associated soils that are known to be rich in humic organic material. There seem to have been no translocation of this radionuclide from the roots to the other parts of the plants.

Substâncias húmicas: sistema de fracionamento sequencial por ultrafiltração com base no tamanho molecular

A sequential system for fractionation by ultrafiltration (SSFU) equipped with advanced membranes filters (molecular size cut-off: 5, 10, 30, 50 and 100 kDalton) of the polyethersulfone type was developed for analytical fractionation of humic substances (HS) extracted from aquatic systems or soils. The device consists of five membrane filters (Sartocon® Micro) operated by a multi-channel peristaltic pump, enabling an easy handling, working in a closed system and with simple collection of the six obtained fractions (F1>100; F2: 100-50; F3: 50-30; F4:30-10; F5: 10-5 and F6 <5 kDalton). Then, the HS sample (250 mL solution 1.0 mg/mL, pH 5.0 to 6.0) to be fractionated is pumped by pump through the series of membrane filters with a tangential flow of 85 mL/min, initial pressure 0.2 to 0.3 bar and permeation flux through the membranes of 0.8 to 1.4 mL/min. The overall time for fractionation and cleaning of the device is about 10 h and 25 mL of each fraction is obtained.

Contaminação do ambiente aquático por pesticidas. Estudo de caso: águas usadas para consumo humano em Primavera do Leste, Mato Grosso - análise preliminar

A preliminary analyses of the possible contamination of superficial and underground water by the active ingredients of the pesticide products used in the surroundings of the urban area of Primavera do Leste, Mato Grosso, Brazil, was carried out. A description of the study region and of its environmental characteristics, which can favor the contamination of the local aquatic environment, was presented. The EPA screening criteria, the groundwater ubiquity score (GUS) and the criteria proposed by Goss were used to evaluate which pesticides might contaminate the local waters. Among the active ingredients studied, several present risks to the local aquatic environment.

Molluscan radiations and landscape evolution in Miocene Amazonia

This PhD study aims to exploit the rich archive provided by the Miocene mollusc fauna of the Pebas Formation and other inland Miocene Amazonian formations to reconstruct landscape evolution and biotic development in lowland Amazonia during the Neogene. Over 160 samples from more than 70 Pebas Formation outcrops mostly collected by the author were processed for this study. Additional samples were collected in Andean areas of Colombia and Venezuela and further material from other northwestern South American basins was studied in museums. Pebas Formation samples and well log data made available by Occidental Peru from three wells in the Marañon Basin in Peru were also investigated. During this study four genera and 74 species from the Pebas Formation have been described and a further 13 species have been introduced in open nomenclature, and several species were reported for the first time. The number of mollusc species attributed to the Pebas fauna has increased from around 50 to 156. The Pebas fauna is characterised as aquatic, endemic and extinct, and is a typical representative of a long-lived lake fauna. Fluvial taxa are not common, (marginal) marine taxa are rare. An additional molluscan fauna from the Miocene Solimões Formation of Brazil, containing 13 fresh water species was also described. The newly documented fauna was used to improve biostratigraphic framework of Miocene Amazonian deposits. Twelve mollusc zones were introduced, the upper eleven of which cover a time interval of approximately seven million years covered previously by only three pollen zones. An age model calculated for the borehole data indicates that the Pebas Formation was deposited between c. 24 and 11 Ma. The areal distribution of the outcropping mollusc zones uncovered a broad dome structure, termed here the Iquitos-Araracuara anteclise in the study area. The structure appears to have influenced river courses and also contributed to edaphic heterogeneity that may have been in part responsible for the current high biodiversity in the study area. The Pebas system was a huge system (> one million km2) dominated by relatively shallow lakes, but also containing swamps and rivers. The system was fed by rivers draining the emergent Andes in the west and lowlands and cratons to the east. The Pebas system was located at sea level and was open to marine settings through a northern portal running through the Llanos Basin and East Venezuela Basin towards the Caribbean. Cyclical baselevel changes possibly related to Mylankhovitch cycles, have been documented in depositional sequences of the Pebas Formation. The composition of the Pebasian mollusc fauna implies that the system was mostly a fresh water system. Such an interpretation is matched by strontium isotope ratios as well as very negative δ18O ratios found in the shells, but is at odds with oligohaline and mesohaline ichnofacies found in the same strata. The mollusc fauna of the Pebas Formation diversified through most of the existence of the lake system. The diversification was mostly the result of in-situ cladogenesis. The success of some of the Pebasian endemic clades is explained by adaptation to fresh water, low oxygen, common unconsolidated lake bottoms (soup grounds) as well as high predation intensity. Maximum diversity was reached at the base of the late Middle to early Late Miocene Grimsdalea pollen zone, some 13 Ma. At the time some 85 species co-occurred, 67 of which are considered as Pebasian endemics. A subsequent drop in species richness coincides with indications of elevated salinities, although a causal relation still needs to be established. Apparently the Pebas fauna went (almost) entirely extinct with the replacement of the lake system into a fluvio-tidal system during the Early Late Miocene, some 11 Ma.

Substâncias húmicas aquáticas: fracionamento molecular e caracterização de rearranjos internos após complexação com íons metálicos

The aquatic humic substances (AHS) investigated in this study were conventionally isolated from Rio Negro waters - Amazonas State/Brazil by means of the collector XAD 8. A special five-stage tangential-flow ultrafiltration device was used for analytical fractionation of AHS. The fractionation patterns (6 fractions each) showed that metal traces remaining in AHS after their XAD 8 isolation have different size distributions. For instance, the major percentage of traces of Ni, Cu, Zn, Cd and Pb (determined using ICP-AES) was preferably complexed by molecules with relatively high molecular size (30-100 kDa) and the following complexation order was characterized: F2 >> F1 = F4 = F5 > F3 > F6. Moreover, the species formed between AHS and metals prepared by spiking, showed distribution patterns changing as a function of the complexation time (ageing process), indicating a slow transformation process and an inner rearrangements in the binding sites within the AHS molecules.

Tensoatividade de ácidos húmicos de procedências distintas

The surface activity of humic acids (HA) is a parameter which might be considered in the evaluation of all types of aggregation of these substances. In this work the surface tension of aquatic and terrestrial-HA aqueous solutions was observed under varied conditions of pH, concentration and ionic strength. Results showed that HA present surface activity for a extent range of concentration. The surface tension decreases with HA concentration increasing and, for all samples exist a concentration value above which a reduction in the rate of the solute migration to the solution surface is observed. This value is sensibly reduced and sharpened with the increasing of the ionic strength. Surface tension is also reduced with the acidity increasing, being a minimum reached between pH 3 and 5. Observed effects are explained in view of conformational arrangements of HA which tend to agglomerate in micelle-like domains in aqueous solutions.

Estudo QSPR sobre os coeficientes de partição: descritores mecânico-quânticos e análise multivariada

Quantum chemistry and multivariate analysis were used to estimate the partition coefficients between n-octanol and water for a serie of 188 compounds, with the values of the q 2 until 0.86 for crossvalidation test. The quantum-mechanical descriptors are obtained with ab initio calculation, using the solvation effects of the Polarizable Continuum Method. Two different Hartree-Fock bases were used, and two different ways for simulating solvent cavity formation. The results for each of the cases were analised, and each methodology proposed is indicated for particular case.

Distribuição de metais e caracterização das constantes de troca entre espécies metálicas e frações húmicas aquáticas de diferentes tamanhos moleculares

In this work the metal distribution and exchange constants between metal species and aquatic humic fractions with different molecular sizes were studied. The aquatic humic substances (AHS) were extracted by XAD-8 resin from water sample collected from Itapitanguí river, São Paulo State, Brazil. The AHS were fractionated in six fractions with different molecular sizes (>100 - <5 kDa) and characterized by several techniques. Molar ratios H/C suggested higher aromaticity for fractions F1 and F6 whereas molar ratios C/N didn´t show any differences regarding the humification degree between the fractions. The UV-Vis absorbance a254/a436 ratio showed higher results for F4 and F5, probably by less condensed features. FTIR studies showed high similarity in the functional groups in the fractions. The highest percentage of traces of Co, Al, Fe, Mn, Cu, Zn and Ni (determined by ICP-AES) was preferably complexed by fractions F3 and F4 with a greater amount of dissolved organic carbon (DOC). In addition, the exchange constants, determined by ultrafiltration method, showed complexes AHS-Fe and AHS-Al with higher stability than complexes AHS-Co in all fractions.

Genome-wide analysis of adaptive molecular evolution in the carnivorous plant Utricularia gibba

The genome of the bladderwort Utricularia gibba provides an unparalleled opportunity to uncover the adaptive landscape of an aquatic carnivorous plant with unique phenotypic features such as absence of roots, development of water-filled suction bladders, and a highly ramified branching pattern. Despite its tiny size, the U. gibba genome accommodates approximately as many genes as other plant genomes. To examine the relationship between the compactness of its genome and gene turnover, we compared the U. gibba genome with that of four other eudicot species, defining a total of 17,324 gene families (orthogroups). These families were further classified as either 1) lineage-specific expanded/contracted or 2) stable in size. The U. gibba-expanded families are generically related to three main phenotypic features: 1) trap physiology, 2) key plant morphogenetic/developmental pathways, and 3) response to environmental stimuli, including adaptations to life in aquatic environments. Further scans for signatures of protein functional specialization permitted identification of seven candidate genes with amino acid changes putatively fixed by positive Darwinian selection in the U. gibba lineage. The Arabidopsis orthologs of these genes (AXR, UMAMIT41, IGS, TAR2, SOL1, DEG9, and DEG10) are involved in diverse plant biological functions potentially relevant for U. gibba phenotypic diversification, including 1) auxin metabolism and signal transduction, 2) flowering induction and floral meristem transition, 3) root development, and 4) peptidases. Taken together, our results suggest numerous candidate genes and gene families as interesting targets for further experimental confirmation of their functional and adaptive roles in the U. gibba's unique lifestyle and highly specialized body plan.

Extração de matéria orgânica aquática por abaixamento de temperatura: uma metodologia alternativa para manter a identidade da amostra

In this work was developed an alternative methodology to separation of aquatic organic matter (AOM) present in natural river waters. The process is based in temperature decreasing of the aqueous sample under controlled conditions that provoke the freezing of the sample and separation of the dark extract, not frozen and rich in organic matter. The results showed that speed of temperature decreasing exerts strongly influence in relative recovery of organic carbon, enrichment and time separation of the organic matter present in water samples. Elemental composition, infrared spectra and thermal analysis results showed that the alternative methodology is less aggressive possible in the attempt of maintaining the integrity of the sample.

Fármacos no meio ambiente

Pharmaceutical drugs have been detected in sewage treatment plants, surface waters, underground waters and potable waters. Some investigations have been conducted in several countries such as Germany, Brazil, Canada, United States, The Netherlands, England and Italy. Patients and animals excrete part of pharmaceuticals used for human and veterinary medicine after administration in domestic sewage or on the soil. Drugs residues which have not been completely removed during passage through a sewage treatment plant (STP) enter the aquatic environment. The effects of such residual drugs in terrestrial and aquatic organisms are scarcely known.

Distribuição de compostos organoclorados nas águas e sedimentos da bacia do rio Piracicaba/SP - Brasil

The great utilization of synthetic and persistent xenobiotic cumulative compounds is the main causes of the deterioration of aquatic ecosystems. The one of objective of this work was the determination of the organochlorine levels in the Piracicaba river basin, situated at the center of São Paulo state. Four PCBs congeners, PCP and HCB were determined by GC-ECD in two different matrices: water and sediments. The pattern of the compound distribution indicated a dominance of PCP, HCB and PCB-200. The results indicated contamination in the sampling points located in Campinas, Piracicaba, Santa Bárbara d'Oeste and Sumaré cities.

Referência geoquímica regional para a interpretação das concentrações de elementos químicos nos sedimentos da bacia do Lago Paranoá - DF

The present study aimed at determining a regional geochemical reference for sediment samples from Lago Paranoá watershed through the formulation of geoaccumulation indexes. The need for obtaining information from areas representing low human impact was the basis of this work. Systematic evaluations of sediment from Lago Paranoá will bring valuable information regarding the potential risk that this layer represents for aquatic organisms. Thus, despite the recent water quality improvements achieved in this ecosystem, contaminants incorporated in the sediments may be remobilized for alterations in the adjacent environment. The adsorption capacity of chemical elements in sediment samples was controlled through the variation in the amounts of organic matter, the mineralogical composition and the granulometric variation. By creating the Sediment Enrichment Index (SEI) through the normalization of analytical data it was possible to establish the magnitude of this enrichment relatively to naturally occurring concentrations all over the region of interest. Normalized values with organic matter were especially useful for the evaluation of lothic systems.

Algas: da economia nos ambientes aquáticos à bioremediação e à química analítica

Algae constitute a large group of many different organisms, essentially aquatic and able to live in all systems giving them sufficient light and humidity. Some algae species have been used in the evaluation or in the bioremediation of aquatic systems. More recently algae have been suggested as interesting tools in the field of analytical chemistry. In this work the most important aspects related to the different uses of algae are presented with a brief discussion.