Contaminação de aqüífero por hidrocarbonetos: estudo de caso na Vila Tupi, Porto Velho - Rondônia

Underground storage tanks (UST) are widely used in the Porto Velho area. A large number of these USTs are in bad condition due to corrosion processes causing groundwater contamination. A large number of these leaking underground fuel tanks (LUFT) are in urban areas but due to the lack of water quality monitoring, they are only detected when there is a high contamination level. This study identified petroleum hydrocarbons, derived from a LUFT, by a silica gel/petroleum ether partitioning gravimetric method and by gas chromatographic analysis of samples collected in wells dug in a gas station and in houses in the aforementioned neighborhood.

Tratamento de água subterrânea contaminada com compostos organoclorados usando ferro elementar e o reagente de Fenton

The remediation of groundwater containing organochlorine compounds was evaluated using a reductive system with zero-valent iron, and the reductive process coupled with Fenton's reagent. The concentration of the individual target compounds reached up to 400 mg L-1 in the sample. Marked reductions in the chlorinated compounds were observed in the reductive process. The degradation followed pseudo-first-order kinetics in terms of the contaminant and was dependent on the sample contact time with the solid reducing agent. An oxidative test with Fenton's reagent, followed by the reductive assay, showed that tetrachloroethylene was further reduced up to three times the initial concentration. The destruction of chloroform, however, demands an additional treatment.

Modelling of the PWR PACTEL vertical steam generator with the TRACE code

The behavior of the nuclear power plants must be known in all operational situations. Thermal hydraulics computer applications are used to simulate the behavior of the plants. The computer applications must be validated before they can be used reliably. The simulation results are compared against the experimental results. In this thesis a model of the PWR PACTEL steam generator was prepared with the TRAC/RELAP Advanced Computational Engine computer application. The simulation results can be compared against the results of the Advanced Process Simulator analysis software in future. Development of the model of the PWR PACTEL vertical steam generator is introduced in this thesis. Loss of feedwater transient simulation examples were carried out with the model.

Analytical procedures for determining Pb and Sr isotopic compositions in water samples by ID-TIMS

Few articles deal with lead and strontium isotopic analysis of water samples. The aim of this study was to define the chemical procedures for Pb and Sr isotopic analyses of groundwater samples from an urban sedimentary aquifer. Thirty lead and fourteen strontium isotopic analyses were performed to test different analytical procedures. Pb and Sr isotopic ratios as well as Sr concentration did not vary using different chemical procedures. However, the Pb concentrations were very dependent on the different procedures. Therefore, the choice of the best analytical procedure was based on the Pb results, which indicated a higher reproducibility from samples that had been filtered and acidified before the evaporation, had their residues totally dissolved, and were purified by ion chromatography using the Biorad® column. Our results showed no changes in Pb ratios with the storage time.

Estimativa de risco de contaminação das águas por pesticidas na região sul do estado do RS

Pesticides can be quite useful in agricultural production, however, some pesticides after application can reach and contaminate the hydric resource. Pesticide monitoring must be careful because it is expensive and lengthy. Thus, in this work, a theoretical prediction was made using the approaches suggested by EPA-USA, the Groundwater Ubiquity Score index (GUS) and the Goss method associated with physicochemical properties of 27 pesticides used in a region in the south of Brazil. The results of this work led to the identification of the pesticides that should be prioritized in the environmental monitoring due to their high potential for contaminating water resources.

Estudo da especiação de arsênio inorgânico e determinação de arsênio total no monitoramento ambiental da qualidade de águas subterrâneas

This work reports an alternative, fast and robust method, for the determination of total As, As(III) and As(V) by HG-AAS without the use of prereductants. The method is based on the different rates of arsine formation of the inorganic As species and the effect of As(III) in the signal obtained for total As. Groundwater and mineral spiked waters were used to sample preservation evaluation. The method was validated by the determination of As in SRM 1640 and used in the determination of total As and its inorganic species in groundwater samples collected from mines in the Iron Quadrangle - MG.

Recent research data on the removal of pharmaceuticals from sewage treatment plants (STP)

Pharmaceutical compounds have been detected in sewage treatment plant (STP) effluents, surface waters and, less frequently, in groundwater and drinking water, all over the world. Different sources are responsible for their appearance in the aquatic environment, however, it is widely accepted that the main sources of this type of pollutant are STP effluents. The adverse effects of pharmaceuticals in the environment include aquatic toxicity, development of resistance in pathogenic bacteria, genotoxicity and endocrine disruption. Thus, the discharge of these compounds to the environment in STP effluents should be minimized.

Ocorrência de agrotóxicos em águas subterrâneas de áreas adjacentes a lavouras de arroz irrigado

The objective this study was to monitor pesticide residues in groundwater at three different times and in seven regions producing rice in southern Brazil, in the 2007/08 season. Imazethapyr and fipronil were found in all regions studied. All groundwater samples from the Planície Costeira Interna to Lagoa dos Patos and Santa Catarina contained at least one pesticide. The lowest number of contaminated samples were detected in the Southern region. The highest frequency of contaminated samples was found after drainage of the rice fields. Only fipronil exceeded limits of potability, in 27% of samples, according European Community criteria.

Análise de risco de contaminação de águas superficiais e subterrâneas por pesticidas em municípios do Alto Paranaíba - MG

A preliminary analyses of the possible contamination of surface and groundwater by the active ingredients of the pesticide products used in the areas with intensive agricultural activities of Alto Paranaíba region, MG, Brazil, was carried out. The active ingredients and formulated products most used in the region were identified and their characteristics of environmental importance were 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.

Fluxos de nutrientes associados às descargas de água subterrânea para a Lagoa Mangueira (Rio Grande do Sul, Brasil)

This study assesses the importance of groundwater discharge to dissolved nutrient levels in Mangueira Lagoon. A transect of an irrigation canal in the margin of Lagoon demonstrated a strong geochemical gradient due to high groundwater inputs in this area. Using 222Rn as a quantitative groundwater tracer, we observed that the flux of dissolved inorganic nitrogen (DIN), silicate and phosphate (1178 and 1977; 26190 and 35652; 167 and 188 mol d-1 for winter and summer, respectively) can continually supply/sustain primary production. The irrigation canals act as an artificial underground tributary and represent a new source of nutrients to coastal lagoons.

Ocorrência, comportamento e impactos ambientais provocados pela presença de antimicrobianos veterinários em solos

Antimicrobials, among other veterinary drugs, are used worldwide in industry and agriculture to protect animal health and prevent economic loss. In recent years, they have been detected in various environmental compartments, including soil, surface and groundwater and have become a topic of research interest. Emphasizing this class of compounds, this review presents the different pathways which veterinary drugs enter in the environment, in particular contaminate soils. Also are presented regulatory aspects and guidelines, adsorption/desorption and degradation of these compounds in soils and the consequences of its dispersal in the environment.

Inventário de agrotóxicos e risco de contaminação química dos recursos hídricos no semiárido cearense

The first diagnosis of risk of environmental contamination was conducted for an area of intense agricultural activity in the semiarid cearense (Baixo Jaguaribe and Litoral de Aracati area). We verified the use of 201 rural products (pesticides) in the region, comprising 151 active ingredients. Regarding the active ingredients evaluated, 15.9% were associated with sediment and 29.8% were dissolved in surface water. The study showed that 13.2% to 36.4% of the active ingredients evaluated were classified as potential contaminants of groundwater resources. The study also revealed the most abundant pesticides and which environmental compartment must be evaluated.

Métodos para análises de HPA e BTEX em águas subterrâneas de postos de revenda de combustíveis: um estudo de caso em Campo Grande, MS, Brasil

Two methods using headspace solid-phase microextraction and gas chromatography - mass spectrometry were developed for the determination of polycyclic aromatic hydrocarbons (PAH) and BTEX. Best results were obtained using DVB/CAR/PDMS fiber, with 10 min extraction at 25 °C and 0.15 min desorption at 260 °C (BTEX), and PDMS/DVB fiber, with 60 min extraction at 90 °C, 10% NaCl and 5 min desorption at 270 °C (PAH). LOD intervals were 3x10-2 - 5x10-2 µg L-1 (BTEX) and 1.6x10-3 - 1.4 µg L-1 (PAH). The methods were applied to forty-five groundwater samples from monitoring wells of gas stations and only benzene level exceeded the limit established by Brazilian regulations.

Painediffusöörin suunnitteluperusteiden kehittäminen

Pesu on tärkeä osa sellun tuotantoprosessia. Eräs tapa toteuttaa sellun pesu on käyttää painediffusööriä. Painediffusööri toimii syrjäytyspesuperiaatteella, eli poistaa sellu-massasta keittolipeää paineistetun pesuveden avulla. Työssä on kehitetty painediffusöörin suunnittelun lähtökohtia keräämällä tietoa laitteen toiminnasta, rakenteesta, valmistuksesta sekä nykyisistä epäkohdista, joihin esitetään parannusmahdollisuuksia. Tärkeimmät kehitysalueet laitteessa ovat valmistus-toleranssien väljentäminen sekä sihdin pystysuuntaisen liikkeen tuottaminen. Laitteen valmistustoleranssit on analysoitu perusteellisesti, ja niiden väljentämis-mahdollisuuksia on tutkittu. Väljentämiseen ehdotetaan erilaisia keinoja. Sihdin liike tuotetaan tällä hetkellä hydrauliikalla. Hydrauliikkakomponenteille on koottu mitoitusohjeita, joiden jälkeen esitellään keinoja hydrauliikkajärjestelmän kehittämiseen. Lopuksi esitellään muita lineaarisen liikkeen tuottamisvaihtoehtoja, joilla hydrauliikan voisi korvata. Rakenteessa käytetyille valmistusmateriaaleille on etsitty olemassa olevat yleisimpien materiaalistandardien mukaiset nimikkeet materiaalinvalinnan helpottamiseksi jatkossa. Pääasiallisten valmistusmateriaalien lisäksi on kerätty tietoa myös vaihtoehtoisista konstruktiomateriaaleista sekä materiaalinvalinnasta ja tuotesuunnittelusta yleensä.

Juvan kunnan jätevedenpuhdistamon ympäristöasioiden parantaminen

Diplomityö on osa Mikkelin ammattikorkeakoulun YTI:ssä vuosina 2005 - 2008 toteutettua ”Yritysten ympäristöriskit” EU-osarahoitteista hanketta. Työn tarkoituksena oli tunnistaa, arvioida ja luokittaa Etelä-Savossa, Juvalla toimivan yhdyskuntajätevedenpuhdistamon ympäristöriskit sekä antaa neuvoja löytyneiden riskien hallintaan. Jätevedenpuhdistamon toiminnasta syntyvät mahdolliset ympäristöriskitekijät tunnistettiin kirjallisuusselvitysten sekä haastattelujen avulla. Riskien tunnistamisen jälkeen riskien kartoittamiseen, arviointiin ja luokittamiseen käytettiin osia eri riskianalyysimenetelmistä. Riskit jaettiin viiteen eri riskiluokkaan; vakavasta riskistä merkityksettömään riskiin. Juvan kunnan jätevedenpuhdistamolla esiintyi neljän pienimmän riskiluokan riskejä, ja vakavia riskejä ei kartoituksessa tullut esille lainkaan. Riskejä arvioitiin niin sanotuissa normaalioloissa. Merkittävin yksittäinen riskitekijä jätevedenpuhdistamolla oli haitallisen tai poikkeavan aineen kulkeutuminen jäteveden mukana puhdistamolle. Tämä voisi heikentää puhdistamon puhdistustulosta merkittävästi. Kun laitosta ajetaan ympäristöluvassa asetettujen vaatimusten mukaisesti ja alueella sijaitsevat teollisuuslaitokset noudattavat heille annettuja määräyksiä, ei Juvan jätevedenpuhdistamolta aiheudu merkittäviä päästöjä maa-perään tai pohjavesiin.