995 resultados para Soil remediation.
Resumo:
Mode of access: Internet.
Resumo:
"July 2007"
Resumo:
"31642"--Colophon.
Resumo:
"32399"--Colophon.
Resumo:
Cover title.
Resumo:
The potentially responsible parties (PRPs) have removed the beaver dams and have collected the sediment samples they need for treatability studies. The treatability studies will establish the correct silt fence to minimize releases of sediment during the actual dredging to occur this fall. The studies will also determine the types and amounts of materials (lime, kiln dust, fly ash, etc.) required to stabilize the sediment, chemically tie up the metals and insure the sediment mixture will bear the weight of the cap on the Interim Storage Cell where the sediment will be placed. The Illinois Environmental Protection Agency (Illinois EPA) anticipates work to be completed by late fall or early winter 2004, if lake and river levels that affect the South Ditch are at their normal seasonal levels.
Resumo:
"September 2003."
Resumo:
Environmental liabilities from accidents in the retail petroleum industry, especially in urban areas, have represented a serious problem whose impact reaches the underground, people's health and even economic losses with the remediation process. In U.S.A. are estimated hundreds of billions of dollars invested in soil remediation processes. The results of the reports and investigative reports of liabilities in fuel stations distributed in the urban area of Natal-RN were used to estimate the local scenario of contamination. This database has been possible to determine the main contaminants (BTEX, PAHs, TOC), affected neighborhoods and types of potentially more impacted soils. Experiments were carried out in order to reverse contamination of this scenario, where the soil type was a factor in the planning, because it influences directly on the effectiveness of remediation techniques studied: Oxidation by hydrogen peroxide and oxidation by sodium persulphate. These oxidants are activated forming free radicals (HO•-, SO4 •-, HO2 • , O2 •-, S2O8 -2, etc) responsible for to mineralize the hydrocarbons and other organic compounds (releasing O2 e CO2). In the activation process, the ferrous ions (II) and ferric (III) were studied as well as hydrogen peroxide activation technique with sodium persulfate, the latter being presented the best efficiency among all the study, when activated with Fe+3. In addition to defining the most efficient technique, the aim of this study was to evaluate the influence of different soils among oxidative techniques, characterizing the effect of the concentration of these oxidants and also the concentration of the catalysts. Exists in most scenarios evaluated the presence of intrinsic total iron soil matrix. The so-called latosols present microaggregates reddish indicating the presence of these reactive species like iron and clayey aspect. The kinetic study was conducted by experimental design and monitoring of the percentage of total carbon (SSM-5000A) in the solid and liquid phases, knowing that 82.4% of the diesel molecule is carbon. Yet organic carbon and pH of liquid samples were analyzed for technical, characterizing the influence of soil type and its operating condition. The Fenton-like technique H2O2 e Fe+2 presented satisfactory oxidation, including sandy soil, but well below the best result. The sodium persulphate only activated with temperature, even in the most favorable soil, did not provide good efficiency. The best technique in the study had the concentration profile with 2,2x10- 1mol.L-1 of Na2S2O8 activated with 6,53x10-1mol.L-1 of H2O2 and 2,5x10-2 Fe3+mol.L-1 which reduced in less than a day 96 contamination in red soil, initially with 66,667 mg of diesel per kg of clean soil
Resumo:
Biochar is a carbonaceous material produced through pyrolysis of biomass. One promising application of biochar is phosphorus recovery from wastewater. Phosphorus is a vital nutrient for plant growth, but its use in fertilizers often leads to runoff or leaching. Wastewater treatment plants discharge large amounts of phosphorus-rich wastewater, contributing to eutrophication and ecological harm. Biochar can sorb phosphorus, retaining it in solid form. In this thesis, two composites made of biomass and dolomite or shells exhibited superior phosphate sorption compared to biochar alone, reaching up to 100% sorption. Biochar also finds use in soil remediation, specifically in cleaning up contaminated soil. Polycyclic aromatic hydrocarbons (PAHs), which can be carcinogenic and toxic, can be present in soil. Biochar adsorb PAHs, preventing their leakage or bioaccumulation. Hetero-PAHs, a subclass of PAHs with nitrogen, sulfur, or oxygen atoms in their ring structures, are particularly challenging to degrade. Little is known about their behavior or sorption onto biochar. In this thesis, biochar and activated carbon were effective in immobilizing PAHs and hetero-PAHs in real soils, with rates of immobilization reaching 100%. Biochar performed equally or better than activated carbon, offering a cost-effective alternative due to its lower price. Biochar reduce of metal(loid)s mobility in soil. Metal(loid)s like lead, zinc, and arsenic can contaminate soil through industrial sources, agricultural runoff, and other pollution, and are toxic to plants and animals, rendering the soil unsuitable for agriculture. When biochar is added to contaminated soil, it binds to metal(loid)s, preventing leaching into the environment. A biomass-dolomite composite was compared to activated carbon for immobilizing metal(loid)s in contaminated soils. The composite generally outperformed activated carbon and exhibited the ability to immobilize arsenic. In summary, biochar shows promise for phosphorus recovery, soil remediation, and reducing the mobility of heavy metals, offering cost-effective and sustainable solutions to these environmental challenges.
Resumo:
This paper presents the study of the remediation of sandy soils containing six of the most common contaminants (benzene, toluene, ethylbenzene, xylene, trichloroethylene and perchloroethylene) using soil vapour extraction (SVE). The influence of soil water content on the process efficiency was evaluated considering the soil type and the contaminant. For artificially contaminated soils with negligible clay contents and natural organic matter it was concluded that: (i) all the remediation processes presented efficiencies above 92%; (ii) an increase of the soil water content led to a more time-consuming remediation; (iii) longer remediation periods were observed for contaminants with lower vapour pressures and lower water solubilities due to mass transfer limitations. Based on these results an easy and relatively fast procedure was developed for the prediction of the remediation times of real soils; 83% of the remediation times were predicted with relative deviations below 14%.
Resumo:
This work reports the study of the combination of soil vapor extraction (SVE) with bioremediation (BR) to remediate soils contaminated with benzene. Soils contaminated with benzene with different water and natural organic matter contents were studied. The main goals were: (i) evaluate the performance of SVE regarding the remediation time and the process efficiency; (ii) study the combination of both technologies in order to identify the best option capable to achieve the legal clean up goals; and (iii) evaluate the influence of soil water content (SWC) and natural organic matter (NOM) on SVE and BR. The remediation experiments performed in soils contaminated with benzene allowed concluding that: (i) SVE presented (a) efficiencies above 92% for sandy soils and above 78% for humic soils; (b) and remediation times from 2 to 45 h, depending on the soil; (ii) BR showed to be an efficient technology to complement SVE; (iii) (a) SWC showed minimum impact on SVE when high airflow rates were used and led to higher remediation times for lower flow rates; (b) NOM as source of microorganisms and nutrients enhanced BR but hindered the SVE due the limitation on the mass transfer of benzene from the soil to the gas phase.
Resumo:
The wide spread use and strong reliance on both fertilizers and pesticides made of agrigenic pollution one of the major contemporary threats to environment and human health. Impacts on the environment vary from local effects, such as eutrophycation1, 2, loss of biodiversity and diminished ecosystem health3, to global effects, such as the aggravation of global warming2, 4 and ozone layer depletion5. The novelty of nanoremediation and its early successes, reported for various contexts, present the prospect for the development of relevant applications for agrigenic contaminants.
Resumo:
The need to increase agricultural yield led, among others, to an increase in the consumption of nitrogen based fertilizers. As a consequence, there are excessive concentrations of nitrates, the most abundant of the reactive nitrogen (Nr) species, in several areas of the world. The demographic changes and projected population growth for the next decades, and the economic shifts which are already shaping the near future are powerful drivers for a further intensification in the use of fertilizers, with a predicted increase of the nitrogen loads in soils. Nitrate easily diffuses in the subsurface environments, portraying high mobility in soils. Moreover, the presence of high nitrate loads in water has the potential to cause an array of health dysfunctions, such as methemoglobinemia and several cancers. Permeable Reactive Barriers (PRB) placed strategically relatively to the nitrate source constitute an effective technology to tackle nitrate pollution. Ergo, PRB avoid various adverse impacts resulting from the displacement of reactive nitrogen downstream along water bodies. A four stages literature review was carried out in 34 databases. Initially, a set of pertinent key words were identified to perform the initial databases searches. Then, the synonyms of those initial key words were used to carry out a second set of databases searches. The third stage comprised the identification of other additional relevant terms from the research papers identified in the previous two stages. Again, databases searches were performed with this third set of key words. The final step consisted of the identification of relevant papers from the bibliography of the relevant papers identified in the previous three stages of the literature review process. The set of papers identified as relevant for in-depth analysis were assessed considering a set of relevant characterization variables.
Resumo:
Environmental nanoremediation of various contaminants has been reported in several recent studies. In this paper, the state of the art on the use of nanoparticles in soil and groundwater remediation processes is presented. There is a substantive body of evidence on the growing and successful application of nanoremediation for a diversity of soil and groundwater contamination contexts, particularly, for heavy metals, other inorganic contaminants, organic contaminants and emerging contaminants, as pharmaceutical and personal care products. This review confirms the competence of the use of nanoparticles in the remediation of contaminated media and the prevalent use of iron based nanoparticles.
Resumo:
Abstract