55,376 research outputs found

    Biological Agents of Bioremediation: A Concise Review

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    Due to intensive agriculture, rapid industrialization and anthropogenic activities have caused environmental pollution, land degradation and increased pressure on the natural resources and contributing to their adulteration. Bioremediation is the use of biological organisms to destroy, or reduce the hazardous wastes on a contaminated site. Bioremediation is the most potent management tool to control the environmental pollution and recover contaminated soil. Use of biological materials, coupled to other advanced processes is one of the most promising and inexpensive approaches for removing environmental pollutants. Bioremediation technology is a beneficial alternative which leads to degrade of pollutants. This article presents the important biological organisms used in bioremediation technologies

    Effort to improve coupled in situ chemical oxidation with bioremediation: a review of optimization strategies

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    Purpose - In order to provide highly effective yet relatively inexpensive strategies for the remediation of recalcitrant organic contaminants, research has focused on in situ treatment technologies. Recent investigation has shown that coupling two common treatments-in situ chemical oxidation (ISCO) and in situ bioremediation-is not only feasible but in many cases provides more efficient and extensive cleanup of contaminated subsurfaces. However, the combination of aggressive chemical oxidants with delicate microbial activity requires a thorough understanding of the impact of each step on soil geochemistry, biota, and contaminant dynamics. In an attempt to optimize coupled chemical and biological remediation, investigations have focused on elucidating parameters that are necessary to successful treatment. In the case of ISCO, the impacts of chemical oxidant type and quantity on bacterial populations and contaminant biodegradability have been considered. Similarly, biostimulation, that is, the adjustment of redox conditions and amendment with electron donors, acceptors, and nutrients, and bioaugmentation have been used to expedite the regeneration of biodegradation following oxidation. The purpose of this review is to integrate recent results on coupled ISCO and bioremediation with the goal of identifying parameters necessary to an optimized biphasic treatment and areas that require additional focus. Conclusions and recommendations - Although a biphasic treatment consisting of ISCO and bioremediation is a feasible in situ remediation technology, a thorough understanding of the impact of chemical oxidation on subsequent microbial activity is required. Such an understanding is essential as coupled chemical and biological remediation technologies are further optimize

    Bioremediation of lead using spore surface displayed proteins

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    Lead is a toxic pollutant very harmful to human health since it accumulates in the body and affects the brain, liver, kidney, and bones. Fetuses can be exposed to lead during pregnancy, which can cause problems with learning later on in the baby’s life. The purpose of this project is to display a lead binding protein on bacterial spore surface for the bioremediation of lead from water. Spores from Bacillus subtilis are very robust and resistant to various harsh environments. Genetically fused to a spore surface protein, the displayed proteins demonstrate enhanced robustness and can be easily produced through sporulation without the need of further purification. PbrR is a regulatory protein that modulates the lead resistance in bacteria. In this project, we fused seven variants of PbrR to the spore surface protein CotC (CotC-PbrRs). The lead binding affinity and specificity of these PbrR variants on the spore surface will be characterized. The robustness of these spores with PbrR will be also evaluated using wastewater samples

    The Regulation and Development of Bioremediation

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    The authors describe how federal statutes regulating hazardous wastes create both incentives and disincentives for exploiting the large potential of bioremediation. Ultimately, they argue for regulation attending more to comparative risks and costs

    Comparison of the efficiency of sodium nitrate and superphosphate as nutrients in the bioremediation of petroleum hydrocarbon polluted water

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    The effect of Aspergillus Niger stimulated with 0.2M sodium nitrate and 0.2M single superphosphate fertilizer (nutrients) was investigated in this study. The ambient temperature averaged 29oC all through the 25 days of the research. The comparison was done using three setups- two samples of the hydrocarbon polluted water were amended with the nutrients and with Aspergillus Niger. The third sample served as control. After twenty five days, it was observed that the sample amended with 0.2M sodium nitrate went through the highest amount of bioremediation: For the total hydrocarbon content, the sample with 0.2M sodium nitrate in it dropped by 78.62% (393 – 84mg/L), the sample with 0.2M superphosphate in it - 72.5% (393 – 108mg/L) and the control sample with the lowest drop of 52.16% (393 – 188mg/L). For the biological oxygen demand, the sample with 0.2M sodium nitrate in it dropped by 71.60% (1832.6 – 520.47), the sample with 0.2M superphosphate in it dropped by 63.37% (1832.6 – 671.3mg/L) and the control sample had the lowest drop of 50.27% (1832.6 – 911.29mg/L). The pH of the samples with nutrients in them were initially acidic but became less acidic with time while the control sample which was initially neutral became more acidic

    Identifying the Burdens and Opportunities for Tribes and Communities in Federal Facility Cleanup Activities: Environmental Remediation Technology Assessment Matrix For Tribal and Community Decision-Makers

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    The cleanup of this country's federal facilities can affect a wide range of tribal and community interests and concerns. The technologies now in use, or being proposed by the Department of Energy, Department of Defense and other federal agencies can affect tribal treaty protected fishing, hunting and other rights, affect air and water quality thereby requiring the tribe to bear the burden of increased environmental regulation. The International Institute for Indigenous Resource Management developed a tribal and community decision-maker's Environmental Remediation Technology Assessment Matrix that will permit tribes and communities to array technical information about environmental remediation technologies against a backdrop of tribal and community environmental, health and safety, cultural, religious, treaty and other concerns and interests. Ultimately, the matrix will allow tribes and communities to assess the impact of proposed technologies on the wide range of tribal and community interests and will promote more informed participation in federal facility cleanup activities