Field Application of Plant Growth Promoting Rhizobacteria Enhanced Phytoremediation on an Urban Brownfield and the Derivation of Direct Soil Contact Values for Weathered Petroleum Hydrocarbons (fraction 3)

Field Application of Plant Growth Promoting Rhizobacteria Enhanced Phytoremediation on an Urban Brownfield and the Derivation of Direct Soil Contact Values for Weathered Petroleum Hydrocarbons (fraction 3) PDF Author: Nicole Knezevich
Publisher:
ISBN:
Category : Hydrocarbons
Languages : en
Pages : 92

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Book Description
There are over 30,000 contaminated brownfield sites in Canada, many of which are located in desirable urban areas; and therefore have a high value for potential redevelopment. The remediation of urban brownfield sites presents a challenge as they frequently contain very complex mixtures of contaminants. Phytoremediation is a cost-effective technology that uses plants to remediate a range of contaminants from the soil. However, the capabilities of currently used phytoremediation systems are often limited due to poor bioavailability of the contaminants, growth inhibition caused by poor soil quality, and the presence of contaminant mixtures. One way to enhance phytoremediation systems is the use of plant growth promoting rhizobacteria (PGPR), naturally present soil bacteria that are able to directly and indirectly influence plant growth and reduce the production of stress ethylene in plants. PGPR enhanced phytoremediation systems (PEPS) have been successfully used to remediate rural sites; however, they have not yet been applied to urban brownfields. In this study a two year field trial was conducted on an urban brownfield site in Toronto, Ontario, Canada, to evaluate the ability of PEPS to enhance plant growth and remediate petroleum hydrocarbons (PHCs) on a mixed contaminant site. The effectiveness of PEPS was evaluated through plant biomass production and PHC remediation. Based on germination rates and biomass production in the field, sunflowers (Helianthus annuus var Mammoth Russian) were recommended for PEPS on urban brownfields. PGPR did not have a consistent effect on plant biomass production during the field trials. The impact of PGPR on the native microbial community was evaluated to ensure there were no adverse effects. Bacterial numbers in the rhizosphere of all planted treatments increased throughout the second field season. The plant species utilized, rather than the PGPR treatment, had the largest impact on the microbial community. A significant decrease in the PHC concentrations was observed during the second field season in planted plots treated with PGPR, with an average percent remediation of 25 percent (%). Therefore, based on the results of the two year field trial, PEPS shows promise as an effective remediation technique for urban brownfield remediation. Concerns were raised that the developed fine- and coarse-grained Ecological Tier 1 Canada-wide standards (CWS) for PHC fraction 3 (F3) based on freshly spiked soils are overly conservative and may result in unnecessary and costly remediation. Although the PHC CWS were revised using more recent toxicological data from field studies, the applicability of the current guidelines to sites with historical PHC contamination warrants further investigation as studies with a limited number of PHC concentrations and a ranked response approach were relied upon to derive the current PHC CWS for F3. In this study, plant toxicity tests were conducted to examine the toxicity of weathered PHC (mostly F3) in a coarse-grained soil to derive direct soil contact values for ecological receptors. Coarse grained field and reference soils were obtained from a landfarm site where PHC sludge had been spread for approximately 35 years. Toxicity tests using plants were conducted following standardized test protocols developed by Environment Canada. Endpoint effective concentrations (EC)/and inhibitory concentrations (IC) 25% were calculated to derive soil standards for F3 in coarse-grained soil protective of plants exposed through direct contact with soil. The proposed guideline values derived for the weathered F3 of 659 and 1,961 milligrams per kilogram (mg/kg), respectively, for agricultural/residential and industrial land use are higher than the current ecological Tier 1 CWS for F3 in coarse-grained soil (300 mg/kg for agricultural/residential land use and 1,700 mg/kg for commercial/industrial land use) and support the derivation of remediation targets higher than the current guideline. Additional studies with a more sensitive test species (i.e., earthworms) and a wider range of PHC concentrations are recommended to confirm this conclusion.

Field Application of Plant Growth Promoting Rhizobacteria Enhanced Phytoremediation on an Urban Brownfield and the Derivation of Direct Soil Contact Values for Weathered Petroleum Hydrocarbons (fraction 3)

Field Application of Plant Growth Promoting Rhizobacteria Enhanced Phytoremediation on an Urban Brownfield and the Derivation of Direct Soil Contact Values for Weathered Petroleum Hydrocarbons (fraction 3) PDF Author: Nicole Knezevich
Publisher:
ISBN:
Category : Hydrocarbons
Languages : en
Pages : 92

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Book Description
There are over 30,000 contaminated brownfield sites in Canada, many of which are located in desirable urban areas; and therefore have a high value for potential redevelopment. The remediation of urban brownfield sites presents a challenge as they frequently contain very complex mixtures of contaminants. Phytoremediation is a cost-effective technology that uses plants to remediate a range of contaminants from the soil. However, the capabilities of currently used phytoremediation systems are often limited due to poor bioavailability of the contaminants, growth inhibition caused by poor soil quality, and the presence of contaminant mixtures. One way to enhance phytoremediation systems is the use of plant growth promoting rhizobacteria (PGPR), naturally present soil bacteria that are able to directly and indirectly influence plant growth and reduce the production of stress ethylene in plants. PGPR enhanced phytoremediation systems (PEPS) have been successfully used to remediate rural sites; however, they have not yet been applied to urban brownfields. In this study a two year field trial was conducted on an urban brownfield site in Toronto, Ontario, Canada, to evaluate the ability of PEPS to enhance plant growth and remediate petroleum hydrocarbons (PHCs) on a mixed contaminant site. The effectiveness of PEPS was evaluated through plant biomass production and PHC remediation. Based on germination rates and biomass production in the field, sunflowers (Helianthus annuus var Mammoth Russian) were recommended for PEPS on urban brownfields. PGPR did not have a consistent effect on plant biomass production during the field trials. The impact of PGPR on the native microbial community was evaluated to ensure there were no adverse effects. Bacterial numbers in the rhizosphere of all planted treatments increased throughout the second field season. The plant species utilized, rather than the PGPR treatment, had the largest impact on the microbial community. A significant decrease in the PHC concentrations was observed during the second field season in planted plots treated with PGPR, with an average percent remediation of 25 percent (%). Therefore, based on the results of the two year field trial, PEPS shows promise as an effective remediation technique for urban brownfield remediation. Concerns were raised that the developed fine- and coarse-grained Ecological Tier 1 Canada-wide standards (CWS) for PHC fraction 3 (F3) based on freshly spiked soils are overly conservative and may result in unnecessary and costly remediation. Although the PHC CWS were revised using more recent toxicological data from field studies, the applicability of the current guidelines to sites with historical PHC contamination warrants further investigation as studies with a limited number of PHC concentrations and a ranked response approach were relied upon to derive the current PHC CWS for F3. In this study, plant toxicity tests were conducted to examine the toxicity of weathered PHC (mostly F3) in a coarse-grained soil to derive direct soil contact values for ecological receptors. Coarse grained field and reference soils were obtained from a landfarm site where PHC sludge had been spread for approximately 35 years. Toxicity tests using plants were conducted following standardized test protocols developed by Environment Canada. Endpoint effective concentrations (EC)/and inhibitory concentrations (IC) 25% were calculated to derive soil standards for F3 in coarse-grained soil protective of plants exposed through direct contact with soil. The proposed guideline values derived for the weathered F3 of 659 and 1,961 milligrams per kilogram (mg/kg), respectively, for agricultural/residential and industrial land use are higher than the current ecological Tier 1 CWS for F3 in coarse-grained soil (300 mg/kg for agricultural/residential land use and 1,700 mg/kg for commercial/industrial land use) and support the derivation of remediation targets higher than the current guideline. Additional studies with a more sensitive test species (i.e., earthworms) and a wider range of PHC concentrations are recommended to confirm this conclusion.

The Use of Plant Growth Promoting Rhizobacteria to Enhance Phytoremediation of Petroleum Hydrocarbon-impacted Soils

The Use of Plant Growth Promoting Rhizobacteria to Enhance Phytoremediation of Petroleum Hydrocarbon-impacted Soils PDF Author: Jolanta Gurska
Publisher:
ISBN:
Category :
Languages : en
Pages : 266

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Book Description
Phytoremediation is a cost-effective and environmentally conscious technology that utilizes plants to remediate a variety of contaminants from the soil. Petroleum hydrocarbons (PHC), as a result of their widespread use are a common environmental problem in soils, and one where phytoremediation would be well suited as a solution. Phytoremediation of PHC proceeds mainly through microbial degradation in plant root zone (rhizosphere) and plant degradation of PHC. The high concentrations of PHC at many sites are an impediment to phytoremediation. The toxicity of PHC hinders plant growth and prohibits remediation. One way to overcome this decrease in plant growth is by employing plant growth promoting rhizobacteria (PGPR). PGPR are naturally present soil bacteria that influence plant growth through direct and indirect methods, and can ultimately act to reduce plant stress. If PHC toxicity could be overcome with the use of PGPR, phytoremediation may become a viable option for remediation of PHC contaminated sites. This study was divided into a field component and a laboratory component, both of which focused on different aspects of phytoremediation of PHC enhanced with PGPR. Previous studies have shown that PGPR-enhanced phytoremediation was successful in the greenhouse. As a result of this, long-term field studies of this system were initiated. Effectiveness was evaluated by assessing plant performance and remediation of PHC in the field. The long-term impact of PGPR on the resident microbial community was evaluated, to ensure there was no detriment to microbial diversity. Following success in the field, lab studies were performed to evaluate the effect of PGPR and PHC by examining both physiological and molecular changes in plants exposed to PHC where PGPR effects were demonstrated. When PGPR were used in field experiments to facilitate phytoremediation, PHC toxicity was alleviated, and this was evident through improved germination, increased plant growth, and improved photosynthetic performance of selected grass plant species. These findings were corroborated at two field sites, one with high and one with low levels of weathered PHC. Addition of PGPR consistently improved remediation at each site. When remediation of PHC was followed over a period of three years, it was found that despite increased plant growth and increased remediation with addition of PGPR, remediation slowed in the second and third year of growth; this was particularly evident at the site with low levels of PHC.

Plant-growth Promoting Rhizobacteria Enhanced Phytoremediation of Saline Soils and Salt Uptake Into Plant Biomass

Plant-growth Promoting Rhizobacteria Enhanced Phytoremediation of Saline Soils and Salt Uptake Into Plant Biomass PDF Author: Greg MacNeill
Publisher:
ISBN:
Category :
Languages : en
Pages : 107

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Book Description
Soil salinity affects an estimated one billion hectares worldwide. Excess salinity inhibits plant growth, limiting crop production. This is caused by osmotic stress in saline soil, nutrient imbalance and specific ion toxicity. There have been many methods of remediation investigated, including excavation, soil washing and phytoremediation. Phytoremediation involves the growth of plants on impacted soils to degrade or sequester contaminants. The remediation of salts relies on the uptake of ions into plant biomass where the salt is sequestered and the biomass can then be harvested. This method removes the salt from the site and leaves the top soil in place, which aids in revegetation after site remediation is completed. Plant-growth promoting rhizobacteria (PGPR) improves plant growth by lowering the levels of stress ethylene within the plant, thereby increasing the biomass available to sequester ions. The objectives of this research were to investigate the efficiency of phytoremediation of salt impacted soils in field remediation sites.

Phytoremediation and Rhizoremediation

Phytoremediation and Rhizoremediation PDF Author: Martina Mackova
Publisher: Springer Science & Business Media
ISBN: 1402049994
Category : Technology & Engineering
Languages : en
Pages : 299

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Book Description
This volume represents an excellent description of the hottest topics in the field of phyto- and rhizoremediation. The book shows especially the importance of cooperation between plant and microorganisms, there is practically no phytoremediation without rhizoremediation. Newest approaches based on methods of molecular biology and genetic engineering are described, as well as plant science achievements.

The Use of Plant Growth-promoting Rhizobacteria (PGPR) and an Arbuscular Mycorrhizal Fungus (AMF) to Improve Plant Growth in Saline Soils for Phytoremediation

The Use of Plant Growth-promoting Rhizobacteria (PGPR) and an Arbuscular Mycorrhizal Fungus (AMF) to Improve Plant Growth in Saline Soils for Phytoremediation PDF Author: Pei-Chun Chang
Publisher:
ISBN: 9780494436097
Category :
Languages : en
Pages : 141

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Book Description
Upstream oil and gas production has caused soil salinity problems across western Canada. In this work we investigated the use of ACC (1-aminocyclopropane-1-carboxylate) deaminase-producing plant growth-promoting rhizobacteria (PGPR) and the arbuscular mycorrhizal fungus (AMF) Glomus intraradices to enhance the efficiency and feasibility of phytoremediation of saline soils. This work involved laboratory and field research for three sites in south east Saskatchewan, Canada.

Bioremediation and Phytoremediation Technologies in Sustainable Soil Management

Bioremediation and Phytoremediation Technologies in Sustainable Soil Management PDF Author: Junaid Ahmad Malik
Publisher: CRC Press
ISBN: 1000570274
Category : Technology & Engineering
Languages : en
Pages : 351

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Book Description
This 4-volume set focuses on the use of microbial bioremediation and phytoremediation to clean up pollutants in soil, such as pesticides, petroleum hydrocarbons, metals, and chlorinated solvents, which reduce the soil's fertility and renders it unfit for plant growth. Volume 2: Microbial Approaches and Recent Trends focuses on new and emerging techniques and approaches to address soil pollution. These include the use of rhizobacteria, archaea, cyanobacteria, and microalgae as biofertilizers and for soil bioremediation efforts. New technologies for assessment of soil bioremediation are explored also. The chapters provide in-depth coverage of the mechanisms, advantages, and disadvantages of the technologies used and highlight the use of different microbial enzymes that are used in the process of bioremediation and phytoremediation to clean up different pollutants without causing damage to the natural environment. Other volumes in the 4-volume set: • Volume 1: Fundamental Aspects and Contaminated Sites • Volume 3: Inventive Techniques, Research Methods, and Case Studies • Volume 4: Degradation of Pesticides and Polychlorinated Biphenyls Together, these four volumes provide in-depth coverage of the mechanisms, advantages, and disadvantages of the bioremediation and phytoremediation technologies for safe and sustainable soil management. The diverse topics help to arm biologists, agricultural engineers, environmental and soil scientists and chemists with the information and tools they need to address soil toxins that are a dangerous risk to plants, wildlife, humans and, of course, the soil itself.

Microbe-Assisted Phytoremediation of Environmental Pollutants

Microbe-Assisted Phytoremediation of Environmental Pollutants PDF Author: Vineet Kumar
Publisher: CRC Press
ISBN: 1000065588
Category : Science
Languages : en
Pages : 210

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Book Description
Microbe-Assisted Phytoremediation of Environmental Pollutants: Recent Advances and Challenges provides comprehensive information on the principles and practical knowledge of microbe-assisted phytoremediation of organic and inorganic pollutants for environmental safety. This book describes the physiological, biochemical, microbiological, and molecular basis of microbe-assisted phytoremediation and contains many relevant topics to fill the gaps in developing an understanding of microbe-assisted phytoremediation of environmental pollutants. The book provides state-of-the-art knowledge on fundamental, practical, and purposeful utilization of plant-associated bacteria (plant growth-promoting rhizobacteria [PGPR] and endophytes) and arbuscular mycorrhizal fungi for plant-growth promotion and enhanced phytoremediation of environmental pollutants in the contaminated matrix. Features: Provides a state-of-the-art overview of microbe-assisted phytoremediation Emphasizes the roles of PGPR, endophytes, and mycorrhizal fungi in assisted phytoremediation Elucidates biochemical and molecular mechanisms of microbe-assisted phytoremediation Details field studies and success stories of microbe-assisted phytoremediation Explores advances, challenges, and future directions in microbe-assisted phytoremediation The book serves as a valuable resource for researchers, ecotoxicologists, environmental scientists and engineers, environmental microbiologists and biotechnologists, environmental health and risk scientists, environmental science managers and administrators, remediation practitioners, environmental policymakers, and students at the postgraduate and doctoral levels in the relevant fields who wish to work on microbe-assisted phytoremediation of pollutants for environmental safety and sustainability.

Phytoremediation

Phytoremediation PDF Author: Abid A. Ansari
Publisher: Springer
ISBN: 3319996517
Category : Science
Languages : en
Pages : 476

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Book Description
This text details the plant-assisted remediation method, “phytoremediation”, which involves the interaction of plant roots and associated rhizospheric microorganisms for the remediation of soil contaminated with high levels of metals, metalloids, fuel and oil hydrocarbons, nano particles, pesticides, solvents, organic compounds and various other contaminants. Many chapters highlight and compare the efficiency and economic advantages of phytoremediation and nano-phytoremediation to currently practiced soil and water treatment practices. Volume 6 of Phytoremediation: Management of Environmental Contaminants continues the series. Taken together, the six volumes provide a broad–based global synopsis of the current applications of phytoremediation using plants and the microbial communities associated with their roots to decontaminate terrestrial and aquatic ecosystems.

Phytoremediation of Metal-Contaminated Soils

Phytoremediation of Metal-Contaminated Soils PDF Author: Jean-Louis Morel
Publisher: Springer Science & Business Media
ISBN: 140204688X
Category : Science
Languages : en
Pages : 357

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Book Description
This is the first book aimed at development of a common language among scientists working in the field of Phytoremediation. Authors of the main chapters are leading scientists in this field. Some of them were among the first ones to have suggested the use of hyperaccumulator plants for extraction of metals from soils. Manuscripts based on lectures presented at the ASI have been revised here to take into account ASI participants’ comments and suggestions.

Enhanced Phytoremediation of Salt-impacted Soils Using Plant Growth-promoting Rhizobacteria (pgpr)

Enhanced Phytoremediation of Salt-impacted Soils Using Plant Growth-promoting Rhizobacteria (pgpr) PDF Author: Shan Shan Wu
Publisher:
ISBN:
Category :
Languages : en
Pages : 153

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Book Description
Soil salinity is a widespread problem that limits crop yield throughout the world. The accumulation of soluble salts in the soil can inhibit plant growth by increasing the osmotic potential of interstitial water, inducing ion toxicity and nutrient imbalances in plants. Over the last decade, considerable effort has been put into developing economical and effective methods to reclaim these damaged soils. Phytoremediation is a technique that uses plants to extract, contain, immobilize and degrade contaminants in soil. The most common process for salt bioremediation is phytoextraction which uses plants to accumulate salt in the shoots, which is then removed by harvesting the foliage. As developing significant plant biomass in saline soils is an issue, a group of free-living rhizobacteria, called plant growth promoting rhizobacteria (PGPR), can be applied to plant seeds to aid plant growth by alleviating salt stress. The principle objective of this research was to test the efficacy of PGPR in improving the growth of plants on salt-impacted soils through greenhouse and field studies. In this research, previously isolated PGPR strains of Pseudomonas putida UW3, Pseudomonas putida UW4, and Pseudomonas corrugata CMH3 were applied to barley (Hordeum valgare C.V. AC ranger), oats (Avena sativa C.V. CDC baler), tall wheatgrass (Agropyron elongatum), and tall fescue (festuca arundinacea C.V. Inferno). PGPR effects on plant growth, membrane stability, and photosynthetic activity under salt stress were examined.