Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review
TL;DR: The biodegradation of PAHs has been observed under both aerobic and anaerobic conditions and the rate can be enhanced by physical/chemical pretreatment of contaminated soil.
About: This article is published in Journal of Hazardous Materials.The article was published on 2009-09-30. It has received 2482 citations till now. The article focuses on the topics: Microbial biodegradation & Biodegradation.
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TL;DR: In this paper, the main anthropogenic sources of polycyclic aromatic hydrocarbons (PAHs) and their effect on the concentrations of these compounds in air are discussed.
2,217 citations
TL;DR: Biochar was most effective, resulting in a 10 fold decrease of Cd in pore water and a resultant reduction in phytotoxicity, and the results highlight the potential of biochar for contaminated land remediation.
1,024 citations
Cites background from "Biodegradation aspects of Polycycli..."
...Compost has been shown to enhance PAH degradation in a number of studies by improving soil texture, oxygen transfer, and providing energy to the microbial population (Haritash and Kaushik, 2009)....
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TL;DR: In this article, a review of the abilities of microorganisms and plants in terms of tolerance and degradation of heavy metals is presented, with special reference to the genomics of heavy metal accumulator plants and the identification of functional genes involved in tolerance and detoxification.
Abstract: Heavy metals are natural constituents of the environment, but indiscriminate use for human purposes has altered their geochemical cycles and biochemical balance. This results in excess release of heavy metals such as cadmium, copper, lead, nickel, zinc etc. into natural resources like the soil and aquatic environments. Prolonged exposure and higher accumulation of such heavy metals can have deleterious health effects on human life and aquatic biota. The role of microorganisms and plants in biotransformation of heavy metals into nontoxic forms is well-documented, and understanding the molecular mechanism of metal accumulation has numerous biotechnological implications for bioremediation of metal-contaminated sites. In view of this, the present review investigates the abilities of microorganisms and plants in terms of tolerance and degradation of heavy metals. Also, advances in bioremediation technologies and strategies to explore these immense and valuable biological resources for bioremediation are discussed. An assessment of the current status of technology deployment and suggestions for future bioremediation research has also been included. Finally, there is a discussion of the genetic and molecular basis of metal tolerance in microbes, with special reference to the genomics of heavy metal accumulator plants and the identification of functional genes involved in tolerance and detoxification.
900 citations
TL;DR: In this article, a general overview on the application of AOPs to pesticides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and total petroleum hydrocarbon (TPHs) contaminated soils remediation is provided.
847 citations
TL;DR: It is demonstrated that biochars are highly heterogeneous materials that, depending on feedstock and HTT, may be suitable for soil application by contributing to the nutrient status and adding recalcitrant C to the soil but also potentially pose ecotoxicological challenges.
Abstract: Biochars are increasingly used as soil amendment and for C sequestration in soils. The influence of feedstock differences and pyrolysis temperature on biochar characteristics has been widely studied. However, there is a lack of knowledge about the formation of potentially toxic compounds that remain in the biochars after pyrolysis. We investigated biochars from three feedstocks (wheat straw, poplar wood, and spruce wood) that were slowly pyrolyzed at 400, 460, and 525°C for 5 h (straw) and 10 h (woodchips), respectively. We characterized the biochars' pH, electrical conductivity, elemental composition (by dry combustion and X-ray fluorescence), surface area (by N adsorption), water-extractable major elements, and cation exchange capacity (CEC). We further conducted differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffractometry to obtain information on the biochars' molecular characteristics and mineralogical composition. We investigated trace metal content, total polycyclic aromatic hydrocarbon (PAH) content, and PAH composition in the biochars. The highest salt (4.92 mS cm) and ash (12.7%) contents were found in straw-derived biochars. The H/C ratios of biochars with highest treatment temperature (HTT) 525°C were 0.46 to 0.40. Surface areas were low but increased (1.8-56 m g) with increasing HTT, whereas CEC decreased (162-52 mmol kg) with increasing HTT. The results of DSC and FTIR suggested a loss of labile, aliphatic compounds during pyrolysis and the formation of more recalcitrant, aromatic constituents. X-ray diffractometry patterns indicated a mineralogical restructuring of biochars with increasing HTT. Water-extractable major and trace elements varied considerably with feedstock composition, with trace elements also affected by HTT. Total PAH contents (sum of EPA 16 PAHs) were highly variable with values up to 33.7 mg kg; irrespective of feedstock type, the composition of PAHs showed increasing dominance of naphthalene with increasing HTT. The results demonstrate that biochars are highly heterogeneous materials that, depending on feedstock and HTT, may be suitable for soil application by contributing to the nutrient status and adding recalcitrant C to the soil but also potentially pose ecotoxicological challenges.
793 citations
References
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TL;DR: Rates of biodegradation depend greatly on the composition, state, and concentration of the oil or hydrocarbons, with dispersion and emulsification enhancing rates in aquatic systems and absorption by soil particulates being the key feature of terrestrial ecosystems.
2,450 citations
"Biodegradation aspects of Polycycli..." refers background in this paper
...most abundant fungi in polluted environments are yeasts [40,41] and they can oxidize PAH with alternative carbon sources....
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...[40] J....
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01 Jan 1997
1,437 citations
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01 Jan 1992
1,412 citations
TL;DR: This review discusses the microbial PAH-degradation with special emphasis on both biological and physico-chemical factors influencing the biodegradation of poorly available PAHs.
1,115 citations
"Biodegradation aspects of Polycycli..." refers background in this paper
...Thus, the degradation rate of HMWPAHs is slow [123]....
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1,082 citations
"Biodegradation aspects of Polycycli..." refers background in this paper
...[137] identified plant enzymes as the causative agents in the transformation of contaminantsmixedwith sediment and soil....
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