A poluição do solo por uso de derivados de petróleo como o grupo de hidrocarbonetos denominado de BTEX (benzeno, tolueno, etil-benzeno e xilenos), apresenta grande risco às comunidades residentes próximas a esses locais. Esses compostos são tóxicos, comprovadamente cancerígenos e podem levar uma pessoa a morte, mesmo em concentrações extremamente baixas. O cidadão, muitas vezes não tem noção do que sejam estes contaminantes e o grande perigo que representam. Milhares de residências têm sido construídas sobre resíduos perigosos que continuam ativos, emitindo gases e/ou contaminando o lençol freático. Em particular, na região de Cubatão, o problema se agrava com o uso indevido de águas de rios e riachos, que por um processo de percolação, acabam sendo contaminados pelos poluentes presentes no solo, podendo ocorrer de o ponto de coleta de água ser próximo a um sítio contaminado. Este estudo relata o isolamento e caracterização de 4 cepas de bactérias isoladas de um solo contaminado com BTEX em Cubatão-SP, através da técnica de enriquecimento seletivo de culturas. A idéia é que estas cepas possam ser utilizadas em futuros processos de biorremediação (tratamento) destes solos. Além disso, o trabalho conta com o auxílio de programas sócio-ambientais existentes no Centro de Capacitação e Pesquisa em Meio Ambiente (CEPEMA-POLI-USP) os quais tem como um dos objetivos conscientizar a população carente cubatense, que faz uso indevido da água contaminada, aos perigos da exposição ao BTEX. / Contaminated soils by hydrocarbons known as BTEX (benzene, toluene, ethylbenzene and xylene), represent a risk to communities who live close to these places. These compounds are toxic, carcinogenic and can cause death to people, even in extremely small concentrations. Citizens often have no idea who and how hazardous are these contaminants. Millions of homes have been built on dangerous actives wastes, emitting gases and contaminating the groundwater. In particular, the problem is worst in Cubatão due inappropriate use of water from rivers and streams, which by a percolation process, contaminate soil. Most of times the water collected points are near from the contaminated site. This study reports the successful isolation and characterization of 4 bacteria strains isolated from an industrial soil in Cubatão-Brazil, using a culture enrichment technique. The idea is use these microorganisms in future soils bioremediation processes (treatment). This work have as partners, social and environmental programs from the Center for Training and Environmental Research (CEPEMA-POLI-USP), which has as goal educate poor people against dangers of BTEX.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第19697号 / 工博第4152号 / 新制||工||1641(附属図書館) / 32733 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 清水 芳久, 准教授 藤川 陽子 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Groundwater contamination and soil salinisation are a major environmental problem worldwide. Living organisms depend largely on groundwater for their survival and its pollution is of course of major concern. It therefore goes without saying that remedial processes and understanding of the mathematical models that describe contaminant transport is of great importance. The theory of contaminant transport requires understanding of the water ow even at the microscopic level. In this study we focus on macroscopic deterministic models based on di erential equations. Here contaminant will refer to nonreactive contaminant. We aim to calculate Lie point symmetries of the one-dimensional Advection-di usion equation (ADE) for various forms of the di usion coe cient and transport velocity. We aim to employ classical Lie symmetry techniques. Furthermore, reductions will be carried out using the elements of the optimal systems. In concluding, the ADE is analyzed for selected forms of the the di usion coe cient and transport velocity via the potential symmetry method. For the potential symmetries obtained, we investigate the associated invariant solutions.

No description available.

Bacteria from dry and wet roadside environments were examined for the ability to degrade hydrocarbons. The kinds and numbers of bacteria observed were similar to those reported in other petroleum contaminated environments. Surface soils (top 2.5 cm) immediately adjacent to the highway pavement and the sediments of shallow drainage ditches contained the highest concentrations of petroleum degrading bacteria (9.8 x 107 CFU/g). Concentration and species diversity of petroleum degrading bacteria decreased with distance from the highway pavement. Chromatographic analysis of highway stormwater runoff and the soil in close proximity to the highway indicated the presence of complex hydrocarbon mixtures of vehicular origin. The concentrations of chloroform extractable hydrocarbons decreased with distance from the highway pavement. Hydrocarbon degradation rates in the roadside environment were determined by the oxidation of radiolabeled [1-14C] hexadecane. Roadside soil and water samples were incubated under nutrient enriched and in situ environmental conditions. Biodegradation rates in environmental samples enriched with inorganic nutrients were 25-126 fold higher than the in situ rates. The highest in situ rates (92 µg hexadecane g-1 solid h-1) occurred in wet surface solid (top 2.5 cm) immediately adjacent to the highway pavement. The findings of the investigation indicate that the roadside environment under study was a petroleum contaminated ecosystem in which biodegradation of hydrocarbon pollutants was greatly influenced by the design of the roadside drainage systems. Furthermore, petroleum degradation in roadside environments can be enhanced by construction of shallow drainage ditches which support aerobic microbial biodegradation.

The purpose of this research was to evaluate the rates, patterns, and pathways involved in the biodegradation of organic contaminants in subsurface environments. Subsurface material was obtained from ten sites in six geographical locations representing diverse environmental conditions. The overall goal was to gain a general understanding of biodegradative mechanisms rather than making site-specific measurements. The biodegradation rates of methanol, phenol, and <i>t</i>-butanol (TBA) were evaluated in static soil/water microcosms. Biodegradation assays were conducted under ambient anoxic conditions, and with the addition of potential electron acceptors (nitrate, nitrite, sulfate) or metabolic inhibitors (molybdate, BESA) to promote different pathways of anaerobic microbial metabolism (nitrate respiration/denitrification, sulfate reduction, or methanogenesis). In unamended systems, biodegradation rates varied considerably between sites. Methanol and phenol were degraded fairly readily. Rates generally ranged from 0.5 to 1.0 mgL⁻¹d⁻¹ for 20°C incubation. Disappearance of methanol and phenol followed zero- to first-order kinetics and was usually immediate, requiring no acclimation period. TBA was relatively recalcitrant in subsurface soils, disappearing at a rate of 0.1-0.3 mgL⁻¹d⁻¹ (20°C). No biodegradation was evident, relative to sterile controls, in certain soils. The pattern of TBA degradation was typically biphasic: a long lag period of slow, linear removal was followed by an abrupt increase in removal rate (albeit still slow). Biodegradation rates were positively correlated with bacterial density for 12 soil samples from 3 sites within a localized area at Blacksburg, Virginia. However, this relationship did not exist between soils from diverse locations. The prevailing electron acceptor conditions govern the catabolic pathways utilized in the anaerobic respiration of organic contaminants. The effects of the added electron acceptors and inhibitors on biodegradation rates varied between sites. Two general types of systems are indicated by relative biodegradation rates, characteristic responses to electron acceptor/inhibitor amendments, and general environmental conditions. "Fast" soils are characterized by a higher flux of water and nutrients, higher biodegradation rates, and rate enhancement upon adding nitrate or sulfate. In "slow" soils, organic contaminants are degraded at lower rates, rates are decreased by adding nitrate, sulfate, or BESA (which inhibits methanogenesis), and rates are increased by adding molybdate (which inhibits sulfate reduction). Nearly all soils tested were capable of sulfate-reducing and methanogenic metabolism, but those populations were more active, and competition between the two groups was less severe, in "fast" soils. In contrast, "fast" soils appeared to harbor an active population of nitrate respiring/denitrifying bacteria, whereas in "slow" soils that metabolic group was inactive, absent, or susceptible to nitrite toxicity. / Ph. D.

A field study was conducted at a residence in Chesapeake, Virginia to determine the effect of setback distances from a drainage ditch on the disposal of septic tank effluent. The study was done from September 1979 to August 1981. The soil used is the Tomotley series belonging to the fine-loamy, mixed, thermic family of Typic Ochraquults. Four prototype trenches were installed at 1.5, 3, 6 and 21 m from the edge of a drainage ditch which was 1.5 m deep. The trenches were pressure dosed equally with 2.4 to 4 cm per day. Replicated nests of sampling wells at depths 90, 150 and 300 cm were placed with distance from the trenches. Continuous stage recorders were positioned 4.5, 29.1 and 60 m from the ditch to monitor water table behavior. Groundwater analysis included fecal coliforms, the NH₄, NO₃, NO₂, Na, Ca, Mg, Cl and PO₄ ions, pH and EC. Ammonium concentrations in the soil beneath the trenches indicated nonuniform effluent infiltration yet more uniform than with conventional gravity flow distribution. High sodium absorption ratios of the septic tank effluent ranging from 18 to 45 did not significantly reduce infiltration rates as no ponding of effluent in the trenches was observed. The existing land surface was sloped greater than the water table gradient resulting in decreasing unsaturated depths with closeness to the ditch. The mean distances between the trench bottom and the water table were 64 cm at 3 m, 80.1 at 6 m and 90.4 cm at 21 m. The accumulation of fecal coliforms, NH₄, P, Cl and total salts (EC) in the groundwaters at 120 to 150 cm depth was inversely proportional to the mean distances from the trench bottoms to the water table. The lack of denitrification occurring underneath the trench with the most extensive unsaturated zone suggests NO₃ may accumulate under disposal systems that have mean unsaturated depths of ≥ 90 cm. Effluent movement was mainly lateral and in the upper zone of the water table with limited vertical movement below the water table surface. An equation applying D-F theory to infinitely deep soil was developed to describe flow for the given drainage system and for the inclusion of standard size drain fields. The current practical setback distance of 21 m is considered counterproductive for effluent treatment for some situations. / Ph. D.

Thesis (M.Sc. (Soil Science)) --University of Limpopo, 2013 / The study was conducted to assess the impact of mining activities on selected soil physical, chemical and microbial properties on farmlands around three selected mining sites. Nine soil samples were collected from each of the following farms : Hans Merensky, Mogoboya and Leon Tom, Foskor Mine and JCI mining sites, respectively. Additional nine soil samples were collected from non-polluted Waterbok farm that serves as a control for the purpose of comparison. The samples were taken at 0–15, 15–30, 30–45 cm depths at three sampling points on each farm for physical, chemical and biological studies. However, soil samples collected for microbial (fungi, bacteria and actinomycetes) counts were surface (0–15 cm) soil samples. Soil chemical properties determined include pHw, electrical conductivity (ECe), exchangeable acidity (EA), organic carbon, available phosphorous, exchangeable cations as well as heavy metal (i.e. Mn, Zn, Cu, Pb, Cd, As and Sb) concentrations. The physical parameters determined include texture (sand, silt and clay) as well as bulk density. Soil pHw and ECe values decreased with depth; and ranged from 6.94 to 6.50 and from 12.24 to 10.76 mS cm-1, respectively. Exchangeable acidity showed a gradual increase with depth and ranged from 0.72 to 0.80 cmol(+)(kg), while percent organic carbon decreased with depth ranging from 1.41 to 2.19 %. Exchangeable cations, particularly K and Mg increased with depth while Ca decreased marginally with soil depth. Available phosphorous content decreased following increases in distance from the pollution source while heavy met.al contamination decreased with soil depth but increased further away from the pollution source. Significantly high loads of Pb, As and Sb were recorded at all depths on the three farms around the mining sites, which were largely responsible for the pollution but worse on the Leon Tom farm; with Pb constituting the greatest pollutant. The concentration of extractable heavy metals in the studied areas was in the order: As >Sb>Pb>Zn>Cu >Mn >Cd. Cadmium level appeared generally very low in all samples while elevated levels of Mn, Cu and Zn were detected at all depths in the polluted soils.Significant differences in microbial levels were detected at the various sampling points. The highest count of 3.82 and 6.20 CFU g-1 for fungi and actinomycete, respectively were both from the Leon Tom farm, while 6.46 CFU g-1 counts for bacteria was obtained from Mogoboya farm. Interestingly, fungal and actinomycetes activities were more sensitive to heavy metal contamination than bacteria that were significantly increased following soil pollution. / National Research Foundation (NRF)

This thesis estimates the spatial extent of chlorinated solvent contamination of the soil at the Naval Air Station, Dallas, then estimates the fate and transport of these contaminants, over time, using the Soil Transport and Fate database and the Vadose-Zone Interactive Processes (VIP) modeling software. Geostatistical analysis identifies two areas with serious chlorinated solvent contamination. Fate and transport modeling estimates that this contamination will degrade and disperse from the soil phase to below regulatory limits within one year, although there is a risk of groundwater contamination. Contaminants are estimated to persist in the water and air phases of the soil. Further sampling is recommended to confirm the results of this study.

by Ho, Kai-Man. / Thesis submitted in: December 2004. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 158-179). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstracts --- p.ii / Contents --- p.vii / List of figures --- p.xiv / List of tables --- p.xvii / Abbreviations --- p.xx / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Poly cyclic Aromatic Hydrocarbons (PAHs) / Chapter 1.1.1 --- Characteristics of PAHs --- p.1 / Chapter 1.1.2 --- Sources of PAHs --- p.3 / Chapter 1.1.3 --- Environmental fates of PAHs --- p.5 / Chapter 1.1.4 --- Effects of PAHs on living organisms --- p.7 / Chapter 1.1.5 --- Summary --- p.10 / Chapter 1.2 --- Target PAH: Benzo[a]pyrene (BaP) --- p.10 / Chapter 1.3 --- PAH contamination in Hong Kong --- p.14 / Chapter 1.4 --- Remediation for PAHs contaminated soils --- p.15 / Chapter 1.4.1 --- Chemical/ Physical methods --- p.15 / Chapter 1.4.2 --- Bioremediation --- p.16 / Chapter 1.5 --- Biodegradation of PAHs by bacteria and fungi --- p.18 / Chapter 1.5.1 --- Tolerance and degradation --- p.18 / Chapter 1.5.2 --- Biodegradation of PAHs by microorganisms --- p.20 / Chapter 1.5.2.1 --- Bacteria --- p.22 / Chapter 1.5.2.2 --- Fungi --- p.23 / Chapter 1.6 --- Environmental standards --- p.26 / Chapter 1.7 --- Strategies of soil sampling and microbial isolation --- p.26 / Chapter 1.7.1 --- Contaminated soil vs. uncontaminated soil --- p.26 / Chapter 1.7.2 --- Native species vs. foreign species --- p.29 / Chapter 1.7.3 --- Background of the sampling areas --- p.30 / Chapter 1.7.3.1 --- North Tsing Yi shipyard --- p.30 / Chapter 1.7.3.2 --- "Tsam Chuk Wan, Sai Kung" --- p.33 / Chapter 1.8 --- Objectives of this study --- p.33 / Chapter 2. --- Materials and Methods --- p.35 / Chapter 2.1 --- Soil Collection --- p.35 / Chapter 2.1.1 --- Abandoned shipyard soil and its sediment soil --- p.35 / Chapter 2.1.2 --- "Tsam Chuk Wan, Sai Kung" --- p.35 / Chapter 2.2 --- Characterization of soils --- p.35 / Chapter 2.2.1 --- Sample preparation --- p.36 / Chapter 2.2.2 --- Soil pH --- p.36 / Chapter 2.2.3 --- Electrical conductivity --- p.36 / Chapter 2.2.4 --- Salinity --- p.36 / Chapter 2.2.5 --- Total organic carbon contents --- p.38 / Chapter 2.2.6 --- Metal analys --- p.is / Chapter 2.2.7. --- Oil and grease content --- p.38 / Chapter 2.2.8 --- Soil texture --- p.39 / Chapter 2.2.9 --- Available ammoniacal nitrogen and oxidized nitrogen --- p.39 / Chapter 2.2.10 --- Available Phosporus --- p.40 / Chapter 2.2.11 --- Total Nitrogen and total Phosporus --- p.40 / Chapter 2.2.12 --- Moisture / Chapter 2.2.13 --- DTPA-extractable metals --- p.41 / Chapter 2.2.14 --- Extraction of PAHs and organic pollutants --- p.41 / Chapter 2.2.14.1 --- Extraction procedures --- p.41 / Chapter 2.2.14.2 --- GC-MSD conditions --- p.41 / Chapter 2.2.14.3 --- Extraction efficiency --- p.43 / Chapter 2.2.15 --- Soil colour --- p.43 / Chapter 2.3 --- Screening and selection of microorganismms --- p.43 / Chapter 2.3.1 --- Isolation of potential BaP-degrading microorganisms --- p.44 / Chapter 2.3.1.1 --- Isolation of bacteria --- p.44 / Chapter 2.3.1.2 --- Isolation of fungi --- p.44 / Chapter 2.3.2 --- Cultures preserving microorganisms --- p.46 / Chapter 2.3.3 --- Screening and selection of microbes --- p.46 / Chapter 2.3.3.1 --- Bacteria --- p.46 / Chapter 2.3.3.2 --- Fungi --- p.46 / Chapter 2.3.4 --- Survival test --- p.47 / Chapter 2.3.5 --- Removal efficiency (RE) towards BaP by the microorganisms --- p.47 / Chapter 2.3.5.1 --- Bacteria --- p.47 / Chapter 2.3.5.2 --- Fungi --- p.48 / Chapter 2.3.6 --- Removal efficiency (RE) --- p.48 / Chapter 2.3.7 --- Relationship of absorbance of bacterial culture and bacterial biomass --- p.49 / Chapter 2.4 --- Identification of selected microorganisms --- p.49 / Chapter 2.4.1 --- Identification of bacterium --- p.49 / Chapter 2.4.1.1 --- 16S rDNA sequencing --- p.49 / Chapter 2.4.1.1.1 --- Primers --- p.49 / Chapter 2.4.1.1.2 --- DNA extraction --- p.51 / Chapter 2.4.1.1.3 --- Specific PCR --- p.51 / Chapter 2.4.1.1.4 --- Gel electrophoresis --- p.51 / Chapter 2.4.1.1.5 --- Purification of PCR products --- p.52 / Chapter 2.4.1.1.6 --- DNA sequencing --- p.52 / Chapter 2.4.1.2 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.53 / Chapter 2.4.1.3 --- Biolog MicroLog´ёØ system (Biolog) --- p.55 / Chapter 2.4.2 --- Identification of fungi --- p.56 / Chapter 2.4.2.1 --- ITS DNA sequencing --- p.56 / Chapter 2.4.2.2 --- Observation under electronic microscope --- p.58 / Chapter 2.5 --- Growth curve of the microorganism --- p.58 / Chapter 2.5.1 --- Bacterium --- p.58 / Chapter 2.5.2 --- Fungi --- p.58 / Chapter 2.6 --- Preparation of Benzo[a]pyrene (BaP) stock solution --- p.58 / Chapter 2.7 --- Comparison of isolated bacterium and fungi --- p.60 / Chapter 2.8 --- Optimization of BaP degradation by selected fungus --- p.60 / Chapter 2.8.1 --- Preparation of straw compost inoculated with selected fungus --- p.60 / Chapter 2.8.2 --- Effect of incubation time --- p.61 / Chapter 2.8.3 --- Effect of initial BaP concentration --- p.61 / Chapter 2.8.4 --- Effect of inoculum size / Chapter 2.8.5 --- Effect of temperature --- p.61 / Chapter 2.8.6 --- Effect of soil pH --- p.62 / Chapter 2.8.7 --- Study of BaP degradation pathway by the microorganisms using GC-MSD --- p.62 / Chapter 2.9 --- Chitin Assay --- p.62 / Chapter 2.10 --- Enzyme assay --- p.63 / Chapter 2.10.1 --- Laccase assay --- p.63 / Chapter 2.10.2 --- Manganese peroxidase assay --- p.63 / Chapter 2.10.3 --- Lignin peroxidase assay --- p.64 / Chapter 2.11 --- Toxicity of treated soil --- p.64 / Chapter 2.12 --- Statistical analysis --- p.65 / Chapter 3. --- Results --- p.66 / Chapter 3.1 --- Soil Collection --- p.66 / Chapter 3.1.1 --- North Tsing Yi shipyard --- p.66 / Chapter 3.1.2 --- "Tsam Chuk Wan, Sai Kung" --- p.66 / Chapter 3.2 --- Characterization of soil samples --- p.71 / Chapter 3.3 --- Extraction efficiency of Benzo[a]pyrene --- p.79 / Chapter 3.4 --- Screening and selection of microorganisms --- p.79 / Chapter 3.4.1 --- Isolation ofpotential BaP-degrading microorganisms --- p.79 / Chapter 3.4.2 --- Screening and selection of microbes --- p.87 / Chapter 3.4.2.1 --- Bacteria --- p.87 / Chapter 3.4.2.2 --- Fungi --- p.93 / Chapter 3.4.3 --- Growth curve of the microorganisms --- p.95 / Chapter 3.4.3.1 --- Bacterium --- p.95 / Chapter 3.4.3.2 --- Fungi --- p.99 / Chapter 3.5 --- Comparison of isolated bacterium and fungi --- p.99 / Chapter 3.6 --- Identification of selected microorganisms --- p.102 / Chapter 3.6.1 --- Identification of bacterium --- p.103 / Chapter 3.6.1.1 --- 16S rDNA sequencing --- p.103 / Chapter 3.6.1.2 --- Midi Sherlock® Microbial Identification System (MIDI) --- p.103 / Chapter 3.6.1.3 --- Biolog MicroLog´ёØ system (Biolog) --- p.107 / Chapter 3.6.2 --- Identification of fungi --- p.107 / Chapter 3.6.2.1 --- ITS DNA sequencing --- p.107 / Chapter 3.6.2.2 --- Observation under electronic microscope --- p.113 / Chapter 3.7 --- Optimization of BaP degradation by the selected fungus: Trichoderma asperellum --- p.107 / Chapter 3.7.1 --- Effect of incubation time --- p.107 / Chapter 3.7.2 --- Effect of inoculum size --- p.113 / Chapter 3.7.3 --- Effect of initial BaP concentration --- p.113 / Chapter 3.7.4 --- Effect of soil pH --- p.113 / Chapter 3.7.5 --- Effect of temperature --- p.117 / Chapter 3.8 --- Determination of breakdown products of BaP by BaP-degrading microorganisms --- p.117 / Chapter 3.9 --- Enzyme assay --- p.117 / Chapter 3.10 --- Evaluation of toxicity by using indigenous bacteria --- p.121 / Chapter 4. --- Discussion --- p.128 / Chapter 4.1 --- Physico-chemical properties of soil samples --- p.128 / Chapter 4.2 --- Determination of BaP and other organic compounds --- p.131 / Chapter 4.3 --- Identification of the microorganisms --- p.132 / Chapter 4.3.1 --- Bacteria --- p.132 / Chapter 4.3.2 --- Fungi --- p.134 / Chapter 4.4 --- Biodegradation by BaP-degrading microorganisms --- p.135 / Chapter 4.4.1 --- Isolation and screening of BaP-degrading microorganisms --- p.135 / Chapter 4.4.2 --- Biodegradation of BaP --- p.137 / Chapter 4.4.2.1 --- Bacteria --- p.137 / Chapter 4.4.2.2 --- Fungi --- p.138 / Chapter 4.4.3 --- BaP degradation pathway --- p.140 / Chapter 4.4.3.1 --- Bacteria --- p.140 / Chapter 4.4.3.2 --- Fungi --- p.140 / Chapter 4.5 --- Optimization of PAH degradation by T. asperellum --- p.143 / Chapter 4.5.1 --- Effect of incubation time --- p.143 / Chapter 4.5.2 --- Effect of initial BaP concentration --- p.144 / Chapter 4.5.3 --- Effect of inoculum size fungus --- p.144 / Chapter 4.5.4 --- Effect of soil pH --- p.145 / Chapter 4.5.5 --- Effect of temperature --- p.146 / Chapter 4.6 --- Comparison the selected bacterium and fungi --- p.146 / Chapter 4.7 --- Evaluation of toxicity by using in indigenous bacteria --- p.148 / Chapter 4.8 --- Post treatment by crude enzyme of Pleurotus pulmonarius --- p.149 / Chapter 4.9 --- Limiting factors for BaP degradation --- p.150 / Chapter 4.10 --- Further Investigations --- p.152 / Chapter 5. --- Conclusion --- p.155 / Chapter 6. --- References --- p.158