No description available.

A grass phytoremediation field study was initiated in July 1997 at the site of a former railroad tie facility that used creosote for tie preservation. The site is contaminated with polycyclic aromatic hydrocarbons (PAHs). A test matrix consisting of 36 planted (clover, fescue and rye grasses) and unplanted cells was established. The focus of the study was to evaluate PAH remediation in fertilized plots that were unplanted or seeded with clover, fescue or rye. Samples were collected from a depth of 15 to 21 cm, and the six most prevalent PAHs, acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and chrysene were quantified. Data from four sampling periods, t=0, 9, 12 and 17 months is presented. At t=9 months, substantial loss of the five lowest molecular weight (LMW) PAHs had occurred, and the loss was attributed to natural attenuation. During the first 9 months, below average precipitation at the site delayed grass root development. Between t=9 and 12 months, above average precipitation was recorded and this appeared to accelerate chrysene removal rates in both the unplanted and planted cells; however, the rate was higher rate in the planted cells. Similarly, fluoranthene and pyrene degradation seemed to be enhanced in the fescue and rye cells. Over the last 8 months of the study, acenaphthene, fluorene and phenanthrene concentrations approached constant, minimum levels suggesting additional removal will be limited. PAH compounds with higher solubility correlated to decreased constituent soil concentrations. Additional sampling was initiated at t=17 months to compare PAH concentrations with depth. This was done because the observed root mass changed significantly with depth. Samples were taken at two additional depths 10 to 15 and 32 to 38 cm. Increased removal of fluoranthene and pyrene was observed in the uppermost zone, suggesting a role for plants in remediation of these 4 ringed PAHs. / Master of Science

The use of nuclear microprobe techniques including: Particle induced x-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) for elemental analysis and quantitative elemental imaging of biological samples is especially useful in biological and biomedical research because of its high sensitivity for physiologically important trace elements or toxic heavy metals. The nuclear microprobe of the Ion Beam Modification and Analysis Laboratory (IBMAL) has been used to study the enhancement in metal uptake of two different plants. The roots of corn (Zea mays) have been analyzed to study the enhancement of iron uptake by adding Fe (II) or Fe (III) of different concentrations to the germinating medium of the seeds. The Fe uptake enhancement effect produced by lacing the germinating medium with carbon nanotubes has also been investigated. The aim of this investigation is to ensure not only high crop yield but also Fe-rich food products especially from calcareous soil which covers 30% of world’s agricultural land. The result will help reduce iron deficiency anemia, which has been identified as the leading nutritional disorder especially in developing countries by the World Health Organization. For the second plant, Mexican marigold (Tagetes erecta), the effect of an arbuscular mycorrhizal fungi (Glomus intraradices) for the improvement of lead-phytoremediation of lead contaminated soil has been investigated. Phytoremediation provides an environmentally safe technique of removing toxic heavy metals (like lead), which can find their way into human food, from lands contaminated by human activities like mining or by natural disasters like earthquakes. The roots of Mexican marigold have been analyzed to study the role of arbuscular mycorrhizal fungi in enhancement of lead uptake from the contaminated rhizosphere.

A dissertation is submitted as MSc research project in partial fulfilment of the requirements for the degree of Master of Science in the School of Geography, Archaeology and Environmental Studies. July 2016. / A major cause of environmental problems, in the vicinity of mine tailings in and around Johannesburg, is Acid Mine Drainage (AMD). In most research, engineered wetlands are used to ameliorate AMD with the use of vegetation to remove or extract heavy metals from the soil (i.e. phytoremediation). Phytoremediation has been defined as a technology that uses plants to extract or immobilize contaminants in soils and waters (Torresdey, 2007). The aim of this study was to assess and quantify the mass pool size of contaminants (macronutrients, micronutrients, non-essential trace elements) within and between a subset of paddocks from various compartments including sediments, aboveground biomass (shoots –stems and leaves), and belowground biomass (roots and rhizomes) of the two wetland plant species present (P. australis and S. corymbosus ). Analyses were done on the wetland paddocks in situ and ex situ applying different methods, water sample metal cations were analysed by ICP-MS and the major anion analysis by chromatography and Ion Chromatography (IC). The sediment and plant samples were subject to X-Ray fluorescence (XRF) analyses of major elements and trace elements. Although analysis was undertaken for numerous trace and metal elements, only a few macronutrients, micronutrients, and non-essential elements with significant importance to the West Wits Mining Operation were selected for this study. The stream water test strips yielded poor results for this extremely contaminated plume receiving environment this suggests that in this system they are not a useful substitute for conventional laboratory analyses. Of the elements tested, only S showed significant differences in concentrations in plants between paddocks, with the highest concentrations and mass in the downstream paddocks ww6 and ww7. These paddocks also had the greatest masses of S in sediments, and water concentrations were also highest in paddocks ww4, ww6 and ww7. P. australis accumulated highest elemental mass than S. corymbosus, with the highest Zn mass of 93%. P. australis accumulated double the mass of U, Cu, Cl, Ca. In both plants, the roots consistently had highest elemental concentration with sequence often as follows roots> shoots> rhizomes. Sediment element mass accumulation of most tested elements significantly increased with depth, except for Zn and U, which decreased with depth. There are few significant differences in the mass distribution of the elements analysed between paddocks, which is assumed to reflect either the heterogeneity in the underlying sediments following construction of the wetlands, or lateral inputs into the system as seepage from other TSFs. Key words: AMD, Wetland, Varkenslaagte Canal, West Wits Mining Operation, metals, sediment, S. corymbosus, P. australis, ICP-MS, XRF. / LG2017

Orientador: Lucia Maria Carareto Alves / Coorientador: Luciana Maria Saran / Banca: Mariana Carina Frigieri / Banca: David Luciano Rosalen / Resumo: A contaminação do solo pode ser decorrente do descarte inadequado de substâncias com potencial poluente ou do uso agrícola prolongado com aplicação de materiais corretivos de acidez, fertilizantes e defensivos. O objetivo deste estudo foi avaliar a distribuição espacial de cádmio (Cd), cromo (Cr) e níquel (Ni) em Latossolo sob plantio direto, convencional e convencional com aplicação de lodo de esgoto, em áreas com exploração agrícola há mais de 80 anos. As concentrações dos metais em 422 amostras de solo foram mensuradas por espectroscopia de absorção atômica com chama ar-acetileno, sendo os extratos obtidos por extração com HNO3, H2O2 e HCl em sistema aberto (USEPA-3050B). As variáveis pH e matéria orgânica também foram determinadas. Os mapas de distribuição espacial foram elaborados a partir do software Spring v. 5.2.7 e auxiliaram na visualização da dispersão dos metais na área de estudo, indicando níveis de contaminação. A análise estatística multivariada por componentes principais diferenciou as amostras de solo de mata nativa das que estão sob atividade agrícola, apontando a uma mesma fonte de contaminação para Cr e Ni, como também para a correlação da matéria orgânica com Cd. Conclui-se que a área estudada apresenta contaminação, em larga escala, por Cd e Cr, e contaminações pontuais por Ni, estando alguns valores dentro da faixa de intervenção / Abstract: Soil contamination may result from inappropriate use of substances with pollution potential or from the prolonged agricultural use with application of acidity corrective materials, fertilizers and pesticides. The aim of this work was to evaluate the spatial distribution of cadmium (Cd), chromium (Cr) and nickel (Ni) in latosol under no tillage, conventional tillage and conventional with sewage sludge application, in agricultural exploration areas for over 80 years. Metals concentration in 422 soil samples were measured by atomic absorption spectroscopy with acetylene-air flame, obtaining the extracts by extraction with HNO3, H2O2 e HCl in open system (USEPA-3050B). The variables pH and organic matter were obtained. Maps of spacial distribution were elaborated by software Spring v. 5.2.7 and assisted in the visualization of the metals dispersion in the study area, indicating contamination levels. The statistical multivariate by main components differentiated the native forest soil samples from those under agricultural activity, pointing to a same contamination source to Cr and Ni, and to the organic matter correlation to Cd as well. It can be concluded that the studied area presents contamination in large scale by Cd and Cr and pontual contamination by Ni, being some of the values into the intervention group / Mestre

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains xi, 145 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 101-104).

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. The three research sites were Cannington Manor South (CMS), Cannington Manor North (CMN) and Alameda (AL). CMS and AL were highly saline, while the CMN site had moderate salinity. Indigenous PGPR were isolated from these sites and tested in greenhouse experiments using authentic salt-contaminated soils taken from the research sites. Increased plant biomass by PGPR and/or AMF was observed. This growth promotion effect varied with plant species, soil salinity and soil fertility. The combination treatment of two previously isolated PGPR Pseudomonas putida UW3 and UW4 (noted as UW3+4) from farm soil in Ontario consistently promoted shoot growth of both barley and oats grown in saline soils by approximately 100%. The indigenous PGPR Pseudomonas corrugata (CMH3) and Acinetobacter haemolyticus (CMH2) also promoted plant growth on par with UW3+4. In addition, in one experiment where alfalfa was tested, UW3+4, CMH2 and CMH3 treatments not only enhanced shoot biomass but also increased root nodulation. For AMF effects, G. intraradices enhanced biomass of oats and barley. Furthermore, the AMF+CMH3 was effective in promoting growth of Topgun ryegrass, while AMF+CMH2 was beneficial for Inferno tall fescue growth in salt impacted soils. The concentration of NaCl in the plants grown in salt-impacted soils ranged from 24 – 83 g/kg. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR and/or AMF treatments. In addition, to determine the importance of nutrient addition to research sites, liquid fertilizer was applied to 2-week old plants. Results demonstrated that fertilizer effectively increased biomass, and more importantly the biomass of PGPR treated plants supplied with fertilizer was approximately 20% higher than that of plants treated with fertilizer alone. Therefore, research sites were then amended with compost before planting of the 2007 field trial. Plant growth promotion by UW3+4 and CMH3 was tested in the summer of 2007 in the field. Prior to planting, soils were sampled from each site for soil salinity analysis. Barley, oats, tall fescue and ryegrass treated with and without PGPR were sown in plots. The plant coverage condition, NaCl concentrations and biomass of plant shoots were assessed to evaluate the PGPR effect. The results showed that PGPR promoted shoot dry weight by 30% - 175%. The NaCl concentrations of barley, oats and tall fescue averaged 53 g/kg, 66 g/kg and 35 g/kg, respectively. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR in the field. The salt removal of the CMN site was the highest among three sites due to the large amount of shoot biomass produced. The amount of salt accumulated in the shoots on the CMN site is estimated to be 1580 kg per hectare per year when both barley and ryegrass are planted together as a mix and treated with PGPR. Based on the field data, the estimated time required to remove 50% salt in the top 50 cm soil is seven years with PGPR treatments, while it takes fifteen years to do so without PGPR. In conclusion, PGPR-promoted phytoremediation was proven to be a feasible and effective remediation technique for soils with moderate salinity.

Although the pesticide DDT has been banned from use in Canada for more than three decades, DDT still persists in Canadian farmlands at detectable levels. Much effort, such as incineration, thermal desorption, and bioremediation, has been used to remediate DDT contaminated soils, but so far it is either too expensive or impractically slow. In this study, a three-year period of field trials was performed to investigate phytoremediation of DDT contaminated soil. In the field trials, millet, fall rye, sugar beet, potato, and pumpkin, treated with plant growth-promoting rhizobacteria (PGPR) were planted on two sites. As well, untreated plants were planted as a control. Plant growth, and 4,4’-DDT plus 4,4’-DDE concentrations in plant tissues and soil were monitored regularly. Comparing the plant growth between PGPR treated and untreated, PGPR significantly promoted the plant growth. On site 1, the root length and root weight of fall rye treated with PGPR were 16% and 44% greater, respectively, compared to the untreated plants. The root and shoot dry weights of millet treated with PGPR were 38% and 47% greater than those untreated plants. Root dry weight of sugar beet treated with PGPR was increased by 74% compared to untreated sugar beet. A significant effect of growth promotion was also observed in pumpkin and potato treated with PGPR. Following plant growth, DDT detection in plants was performed. 4,4’-DDT and 4,4’-DDE were found in plant tissues of fall rye, millet, sugar beet, and pumpkin. The concentrations of 4,4’-DDT and 4,4’-DDE in fall rye roots were 0.61 and 0.59 μg/g, respectively. In pumpkin tissues at harvest, 4,4’-DDT and 4,4’-DDE concentrations were 0.67 and 1.64 μg/g in roots, 1.06 and 2.05 μg/g in the lower stems, and 0.2 and 0.32 μg/g in the upper stems. The data indicated that it is feasible to phytoremediate DDT from contaminated soil. In addition, 4,4’-DDT concentrations in soils with different plant species were determined. In millet plot on site 1, 4,4’-DDT concentration in rhizosphere soil dropped by 41% in 2006 compared to 4,4’-DDT concentration at t0. In sugar beet plot on site 1, 28% of 4,4’-DDT dropped in rhizosphere soil in 2007. In pumpkin plot on site 1, 4,4’-DDT in rhizosphere soil was decreased by 22% in 2007. The results show that 4,4’-DDT concentration in rhizosphere soil was significantly lower than the initial level of DDT. Based on the data of 4,4’-DDT in soils and plant tissues, a mass balance was constructed and calculated. The preliminary mass balance shows that the total amount that DDT decreased in rhizopshere soil approximately equals to the total amount of DDT accumulated in plant tissues. This indicates that phytoextraction is the mechanism of DDT phytoremediation. In addition, PGPR promoted plant growth and then enhanced the phytoremediation efficiency of DDT. Therefore, the research indicates that PGPR assisted phytoremediation has a great potential for remediation of DDT and other chlorinated aromatics from impacted soil.

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. The three research sites were Cannington Manor South (CMS), Cannington Manor North (CMN) and Alameda (AL). CMS and AL were highly saline, while the CMN site had moderate salinity. Indigenous PGPR were isolated from these sites and tested in greenhouse experiments using authentic salt-contaminated soils taken from the research sites. Increased plant biomass by PGPR and/or AMF was observed. This growth promotion effect varied with plant species, soil salinity and soil fertility. The combination treatment of two previously isolated PGPR Pseudomonas putida UW3 and UW4 (noted as UW3+4) from farm soil in Ontario consistently promoted shoot growth of both barley and oats grown in saline soils by approximately 100%. The indigenous PGPR Pseudomonas corrugata (CMH3) and Acinetobacter haemolyticus (CMH2) also promoted plant growth on par with UW3+4. In addition, in one experiment where alfalfa was tested, UW3+4, CMH2 and CMH3 treatments not only enhanced shoot biomass but also increased root nodulation. For AMF effects, G. intraradices enhanced biomass of oats and barley. Furthermore, the AMF+CMH3 was effective in promoting growth of Topgun ryegrass, while AMF+CMH2 was beneficial for Inferno tall fescue growth in salt impacted soils. The concentration of NaCl in the plants grown in salt-impacted soils ranged from 24 – 83 g/kg. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR and/or AMF treatments. In addition, to determine the importance of nutrient addition to research sites, liquid fertilizer was applied to 2-week old plants. Results demonstrated that fertilizer effectively increased biomass, and more importantly the biomass of PGPR treated plants supplied with fertilizer was approximately 20% higher than that of plants treated with fertilizer alone. Therefore, research sites were then amended with compost before planting of the 2007 field trial. Plant growth promotion by UW3+4 and CMH3 was tested in the summer of 2007 in the field. Prior to planting, soils were sampled from each site for soil salinity analysis. Barley, oats, tall fescue and ryegrass treated with and without PGPR were sown in plots. The plant coverage condition, NaCl concentrations and biomass of plant shoots were assessed to evaluate the PGPR effect. The results showed that PGPR promoted shoot dry weight by 30% - 175%. The NaCl concentrations of barley, oats and tall fescue averaged 53 g/kg, 66 g/kg and 35 g/kg, respectively. There was no evidence of an increase in NaCl concentrations of plant tissue by PGPR in the field. The salt removal of the CMN site was the highest among three sites due to the large amount of shoot biomass produced. The amount of salt accumulated in the shoots on the CMN site is estimated to be 1580 kg per hectare per year when both barley and ryegrass are planted together as a mix and treated with PGPR. Based on the field data, the estimated time required to remove 50% salt in the top 50 cm soil is seven years with PGPR treatments, while it takes fifteen years to do so without PGPR. In conclusion, PGPR-promoted phytoremediation was proven to be a feasible and effective remediation technique for soils with moderate salinity.

Although the pesticide DDT has been banned from use in Canada for more than three decades, DDT still persists in Canadian farmlands at detectable levels. Much effort, such as incineration, thermal desorption, and bioremediation, has been used to remediate DDT contaminated soils, but so far it is either too expensive or impractically slow. In this study, a three-year period of field trials was performed to investigate phytoremediation of DDT contaminated soil. In the field trials, millet, fall rye, sugar beet, potato, and pumpkin, treated with plant growth-promoting rhizobacteria (PGPR) were planted on two sites. As well, untreated plants were planted as a control. Plant growth, and 4,4’-DDT plus 4,4’-DDE concentrations in plant tissues and soil were monitored regularly. Comparing the plant growth between PGPR treated and untreated, PGPR significantly promoted the plant growth. On site 1, the root length and root weight of fall rye treated with PGPR were 16% and 44% greater, respectively, compared to the untreated plants. The root and shoot dry weights of millet treated with PGPR were 38% and 47% greater than those untreated plants. Root dry weight of sugar beet treated with PGPR was increased by 74% compared to untreated sugar beet. A significant effect of growth promotion was also observed in pumpkin and potato treated with PGPR. Following plant growth, DDT detection in plants was performed. 4,4’-DDT and 4,4’-DDE were found in plant tissues of fall rye, millet, sugar beet, and pumpkin. The concentrations of 4,4’-DDT and 4,4’-DDE in fall rye roots were 0.61 and 0.59 μg/g, respectively. In pumpkin tissues at harvest, 4,4’-DDT and 4,4’-DDE concentrations were 0.67 and 1.64 μg/g in roots, 1.06 and 2.05 μg/g in the lower stems, and 0.2 and 0.32 μg/g in the upper stems. The data indicated that it is feasible to phytoremediate DDT from contaminated soil. In addition, 4,4’-DDT concentrations in soils with different plant species were determined. In millet plot on site 1, 4,4’-DDT concentration in rhizosphere soil dropped by 41% in 2006 compared to 4,4’-DDT concentration at t0. In sugar beet plot on site 1, 28% of 4,4’-DDT dropped in rhizosphere soil in 2007. In pumpkin plot on site 1, 4,4’-DDT in rhizosphere soil was decreased by 22% in 2007. The results show that 4,4’-DDT concentration in rhizosphere soil was significantly lower than the initial level of DDT. Based on the data of 4,4’-DDT in soils and plant tissues, a mass balance was constructed and calculated. The preliminary mass balance shows that the total amount that DDT decreased in rhizopshere soil approximately equals to the total amount of DDT accumulated in plant tissues. This indicates that phytoextraction is the mechanism of DDT phytoremediation. In addition, PGPR promoted plant growth and then enhanced the phytoremediation efficiency of DDT. Therefore, the research indicates that PGPR assisted phytoremediation has a great potential for remediation of DDT and other chlorinated aromatics from impacted soil.