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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The lure of pedogenesis : an anthropological foray into making urban soils in contemporary France

Meulemans, Germain January 2017 (has links)
This thesis is an anthropological inquiry into the emergence of urban soils as matters of concern in the worlds of soil scientists and other fields more traditionally involved with cities. Through the lens of soil-making practices, it seeks to elucidate the specificity of urban pedogenesis, including the growth of soils and the lives of the humans associated with them. City soils have typically been neglected in modern thinking about nature and urbanism. They have long been framed solely as a technical question for engineers which seemed to require no further pondering until – in the last two decades – they entered the scope of the soil sciences. This thesis draws on over thirteen months of multi-locale fieldwork conducted in Paris and Lorraine with soil scientists, gardeners and foundation builders. The research does not define a priori what should count as 'urban', 'agricultural' or 'natural' soils. Building on scholarship in anthropology, the soil sciences, science studies, and speculative philosophy, it follows how these actors learn to be affected in the material performance of different relations between people and soils. The chapters are built in counterpoint to one another, occasionally turning to narrative to complement analysis and more traditional ethnography. Each chapter pulls a different diffractive string from the mesh of urban soil matters, and follows where it leads. As ways of knowing that emerge from soil construction are described, the question of what making soils does to knowing them becomes a central thread of the thesis. In this, it looks at how soils participate in apparatuses where they become 'lures for feelings' – affective interweavings in which worlds are experienced.
2

Anthropogenic influences on soil microbial properties

Menefee, Dorothy January 1900 (has links)
Master of Science / Department of Agronomy / Ganga M. Hettiarachchi / Human activities have the potential to alter soil biochemical properties in a number of different ways. This thesis will focus on how agricultural practices (tillage and cropping system), climate change, and urban soil pollution (primarily lead and arsenic) affect soil biochemical properties. Two incubation studies were conducted to determine how human activities influence soil biochemical properties. The first study focused on how altered temperature and moisture regimes affected soil properties from four different agroecosystems. Four different soils were incubated under two different soil preparation methods (sieved <4mm and <0.25 mm), three different temperature treatments (12, 24, and 36°C), and two different moisture treatments (field capacity and 80% of field capacity) for 180 days. Destructive samples were taken at 7, 30, 60, 120, and 180 days and the soil microbial community was analyzed using phospholipid fatty acid analysis (PLFA). The second study investigated how soil amendment treatments (Mushroom Compost and Composted Biosolids) of an industrially contaminated site affected the biochemical properties of that soil. Surface soil samples collected 435 days after compost addition from urban garden test plots located adjacent to a former rail yard in Monon, Indiana. Soils were incubated for 30 days to stimulate microbial activity. Following incubation, the soil was analyzed for PLFA, soil enzymes, and available metal fractions. In the first study the greatest differences were found between the <4mm and the <0.25 mm size fractions – which highlights the effect of soil aggregation and structure on microbial populations. After aggregation effects, temperature treatment had the next largest effect on microbial populations, with the greatest biomass in the middle (24°C) treatment. The second study assessed different soil amendments on soil microbial properties and metal availability. Composted biosolids reduced metal availability and increased microbial enzyme activity and biomass.
3

Soil Carbon Accumulation in an Urban Ecosystem: Canopy Cover and Management Effects

Kang, Katherina A 05 1900 (has links)
Black carbon (BC), a stable form of organic carbon (OC), is a byproduct of the incomplete combustion of biomass, biofuels, and fossil fuel. The main objectives of this research are to examine the spatial distribution of OC and BC in urban soil and determine the influence of tree canopy cover and landscape maintenance on soil carbon accumulation. Soil sampling was conducted at 29 sites throughout the City of Denton, Texas, in May 2019. Samples were collected from underneath post oak canopies and in adjacent open areas and were analyzed for total carbon (TC), total organic carbon (TOC), total N (TN), C:N ratio, and BC. Although maintenance levels had no significant effect, TOC was greater underneath trees (5.47%, 5.30 kg/m2) than lawns (3.58%, 4.84 kg/m2) at the surface 0-10 cm. Total nitrogen concentration was also greater underneath trees (0.43%) than lawns (0.31%) at the surface 0-10 cm. Preliminary results for BC were closely correlated to TOC. The lack of difference in C:N ratio between cover types indicates that leaf litter quality may not be the primary driving factor in soil C and N accumulation. Instead, differences in soil properties may be best explained by manual C inputs and greater atmospheric deposition of C and N to soils with tree canopy cover. Identifying patterns and potential drivers of soil OC and BC accumulation is important because soil carbon sequestration not only reduces atmospheric CO2, but also may provide additional pollution mitigation benefits, thereby contributing to a more sustainable urban environment.
4

Biosolids as a source of soil conditioning and fertility for turfgrass

Badzmierowski, Mike J. 04 November 2019 (has links)
Wastewater treatment plants are shifting towards producing exceptional quality (EQ) biosolids to increase recycling rates to land, especially urban areas. Other methods of improving the environmental impact of wastewater treatment includes additions of iron (Fe) to reduce phosphorus (P) concentrations in outgoing treated water and precipitate the P into the biosolids. Proper management of biosolids to rehabilitate anthropogenically disturbed urban soils for improved plant growth and effects on the cycling of nutrients requires further study. Our objectives were: 1) to determine whether various EQ biosolids could be managed to improve degraded soil properties and turfgrass quality while minimizing risk of P loss in a field study; and 2) to use spectral reflectance data to compare relationships of vegetation indices to soil and turfgrass parameters. We found that after an initial lag-time of one year, biosolids amendments increased turfgrass clipping biomass and aesthetic quality greater than did synthetic fertilizer. Repeated topdressing applications of biosolids reduced soil bulk density and increased soil organic carbon (OC) and nitrogen (N) stocks. Biosolids applied at the agronomic N rate did not increase water-soluble P (15 and 18 mg P kg-1 of soil) compared to biosolids applied at the agronomic P rate (9.6 mg P kg-1 of soil) and synthetic fertilizer (13 mg P kg-1 of soil) after five years. We further demonstrated at this field site that collecting continuous data improves spectral reflectance vegetation indices relationships to turfgrass quality, clipping biomass, and tissue N accumulation. Soil volumetric water content was best correlated to the water band index (r = 0.60) and the green-to-red ratio index (r = 0.54) vegetation indices. Differences in soil and turfgrass measured parameters were best detected when there was drought-stressed versus irrigated turfgrass. / Doctor of Philosophy / Biosolids are the sanitized and nutrient-rich organic solids and semi-solids resulting from treatment of wastewater. The nutrient-rich organic solids provide plant-essential elements (e.g., nitrogen) and can improve soil physical parameters such as soil compaction. Wastewater treatment plants are adopting processes that produce cleaner, exceptional quality (EQ) biosolids to increase biosolids recycling rates to land, especially to urban areas to improve urban soil quality. Adding iron to treated wastewater further improves the quality of biosolids and effluent released to surface water by removing phosphorus from wastewater and concentrating this essential plant nutrient within biosolids. Our research objectives were to quantify the potential benefits of EQ biosolids for improving degraded urban soils, providing sufficient plant available nitrogen to improve turfgrass quality, avoiding increasing soil phosphorus to levels that could result in pollution, and increasing the long-term storage of soil carbon to mitigate climate change. We learned that biosolids were the best long-term solution for providing a high quality turfgrass stand and improve soil properties. Repeated applications of EQ biosolids reduced soil bulk density and increased soil organic carbon and nitrogen stocks. The increased iron in the biosolids reduced water-soluble phosphorus and may reduce phosphorus loss to surface waters.
5

Polycyclic aromatic hydrocarbons (PAHs) in roadside soils and vegetation in Hong Kong.

January 2009 (has links)
Zou, Huiling. / Thesis submitted in: November 2008. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 159-176). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgements --- p.vi / Table of contents --- p.viii / List of tables --- p.x / List of figures --- p.xiii / Abbreviations --- p.xv / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Background --- p.1 / Chapter 1.1.1 --- Physicochemical properties of polycyclic aromatic hydrocarbons --- p.1 / Chapter 1.1.2 --- Sources of PAHs --- p.4 / Chapter 1.1.3 --- Toxicity of PAHs --- p.5 / Chapter 1.1.4 --- Fate of PAHs in environment --- p.6 / Chapter 1.1.5 --- Soil physicochemical and microbiological properties --- p.16 / Chapter 1.1.6 --- Geography and climate of Hong Kong --- p.17 / Chapter 1.1.7 --- Traffic status in Hong Kong --- p.17 / Chapter 1.1.8 --- Research status in Hong Kong --- p.18 / Chapter 1.2 --- "Significant, objectives and outline of this study" --- p.18 / Chapter 1.2.1 --- Research significance --- p.18 / Chapter 1.2.2 --- Research objectives and thesis outline --- p.19 / Chapter Chapter 2 --- PAH concentrations and their seasonal variations in roadside soils in Hong Kong / Chapter 2.1 --- Introduction --- p.20 / Chapter 2.2 --- Materials and methods --- p.22 / Chapter 2.2.1 --- Soil sampling --- p.22 / Chapter 2.2.2 --- Soil physicochemical properties analysis --- p.24 / Chapter 2.2.3 --- Soil PAH analysis --- p.25 / Chapter 2.2.3.1 --- Extraction of PAHs --- p.25 / Chapter 2.2.3.2 --- Cleanup and concentration of the extract --- p.25 / Chapter 2.2.3.3 --- Determination of PAHs --- p.26 / Chapter 2.2.3.4 --- Calibration standards and recovery --- p.26 / Chapter 2.2.4 --- Statistical analysis --- p.28 / Chapter 2.3 --- Results and discussion --- p.29 / Chapter 2.3.1 --- Soil PAH contents and their relationships with soil physicochemical properties and AADT --- p.29 / Chapter 2.3.1.1 --- Soil PAHs --- p.29 / Chapter 2.3.1.2 --- Soil physicochemical properties --- p.38 / Chapter 2.3.1.3 --- Relationships of PAH contents with soil physicochemical properties and AADT --- p.39 / Chapter 2.3.2 --- Seasonal variations of PAH contents of roadside soils --- p.50 / Chapter 2.4 --- Conclusion --- p.56 / Chapter Chapter 3 --- "PAH concentrations in roadside vegetation, dusts and soils" / Chapter 3.1 --- Introduction --- p.58 / Chapter 3.2 --- Materials and methods --- p.59 / Chapter 3.2.1 --- Sampling --- p.59 / Chapter 3.2.2 --- Soil physicochemical properties analysis --- p.60 / Chapter 3.2.3 --- PAHs analysis --- p.60 / Chapter 3.2.3.1 --- Extraction of PAHs --- p.60 / Chapter 3.2.3.2 --- Cleanup and concentration of the extract --- p.60 / Chapter 3.2.3.3 --- Determination of PAHs --- p.61 / Chapter 3.2.3.4 --- Calibration standards and recovery --- p.61 / Chapter 3.2.4 --- Statistical analysis --- p.61 / Chapter 3.3 --- Results and discussion --- p.62 / Chapter 3.3.1 --- Soil physicochemical properties --- p.62 / Chapter 3.3.2 --- PAH concentrations --- p.62 / Chapter 3.3.2.1 --- Soil PAHs --- p.62 / Chapter 3.3.2.2 --- Dust PAHs --- p.65 / Chapter 3.3.2.3 --- Vegetation PAHs --- p.71 / Chapter 3.3.3 --- PAH profile --- p.80 / Chapter 3.3.4 --- PAH sources --- p.83 / Chapter 3.3.5 --- PCA and HCA --- p.88 / Chapter 3.3.6 --- "Relationships of PAH contents between vegetation, dust and soil, and soil physicochemical properties and AADT" --- p.99 / Chapter 3.4 --- Conclusion --- p.124 / Chapter Chapter 4 --- Vertical and horizontal distribution of PAHs in roadside soil and their influences on soil microbial characteristics / Chapter 4.1 --- Introduction --- p.126 / Chapter 4.2 --- Materials and methods --- p.127 / Chapter 4.2.1 --- Sampling --- p.127 / Chapter 4.2.2 --- Soil physicochemical properties analysis --- p.128 / Chapter 4.2.3 --- Soil microbial biomass carbon analysis --- p.128 / Chapter 4.2.4 --- Soil microbial community analysis --- p.128 / Chapter 4.2.5 --- Soil enzyme activity analysis --- p.129 / Chapter 4.2.6 --- Soil PAH analysis --- p.130 / Chapter 4.2.7 --- Statistical analysis --- p.130 / Chapter 4.3 --- Results and discussion --- p.131 / Chapter 4.3.1 --- Vertical distribution --- p.131 / Chapter 4.3.2 --- Horizontal distribution --- p.137 / Chapter 4.3.3 --- Influences of roadside soil PAH on microbial characteristics --- p.142 / Chapter 4.4 --- Conclusion --- p.153 / Chapter Chapter 5 --- General conclusion / Chapter 5.1 --- Summary of findings --- p.155 / Chapter 5.2 --- Limitations of the study --- p.157 / Chapter 5.3 --- Implications for further studies --- p.158 / References --- p.159
6

Urban brownfields to gardens : minimizing human exposure to lead and arsenic

Defoe, Phillip Peterson January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / Ganga M. Hettiarachchi / Urban gardens have been a popular re-use option in the transformation of brownfields—located in older industrialized cities and near peri-urban developments. They provide accessible, available, and affordable supplies of fresh fruits and vegetables, effectively reducing the enigma of “food deserts” across U.S. cities. However, direct (soil ingestion, inhalation) and indirect (soil-plant-human) human exposure concerns about real or perceived trace element contamination in urban soils persist due to previous use. Elevated lead (Pb) and/or arsenic (As) concentrations were found at two (Tacoma and Seattle, WA) urban gardens. The Tacoma site was contaminated with Pb (51 to 312 mg kg-1) and As (39 to 146 mg kg-1), whereas soil Pb at the Seattle site ranged from 506 to 2,022 mg kg-1, and As concentrations were < 20 mg kg-1. Experimental design at both sites was a randomized complete block with a split-plot arrangement (main plots: biosolids/compost vs. non-amended control; sub-plot: plant type). Tacoma site treatment included a Class A biosolids mix (TAGRO) with dolomite. The Seattle site was amended with Cedar-Grove Compost (CGC) plus dolomite. Efficacy of biosolids/compost amendment in reducing Pb and As concentrations was evaluated using root, leafy, and fruit vegetables. Soil Pb and As bioaccessibility were also evaluated. Food chain transfer of Pb and As in vegetables due to surface contamination of produce samples were evaluated on the basis of cleaning procedures. A laboratory incubation study and a controlled greenhouse experiment were conducted on soils collected from the Tacoma site. Effectiveness of addition of laboratory synthesized ferrihydrite (Fh: iron oxyhydroxide) and TAGRO mix, each alone or in combination were screened and tested on the Pb and As co-contaminated Tacoma soil. Extended X-ray Absorption Fine Structure (EXAFS) spectroscopy studies of Pb and As were conducted on incubation study samples to understand treatment-induced Pb- and As-speciation changes. Dilution of soil Pb (10 to 23%) and As (12 to 25%) were observed for biosolids amendment at the Tacoma site, while CGC amendment resulted in 20 to 50% dilution in soil Pb at the Seattle site. Biosolids and CGC amendments reduced Pb concentrations in the vegetables by 50% to 71%. At both sites, Pb concentrations of root vegetables exceeded the MLs established by the Food and Agriculture Organization (FAO) and the World Health Organization (WHO). Arsenic concentrations in vegetables were below an estimated ML and were reduced by 46% to 80% when grown on biosolids amended soils. Laboratory cleaning further reduced Pb and As food-chain transfer in vegetables grown in contaminated urban soils. Laboratory incubation and greenhouse studies showed dissolution of Pb in TAGRO plus Fh, and Pb concentrations in Fh amendments were significantly lower than the other amendments. Bioaccessible Pb and As were low. Significant reductions in bioaccessible As were observed when soils were amended with both TAGRO and Fh. X-ray absorption spectroscopy results indicated that chloropyromorphite-like (stable Pb phosphates) phases were the most dominant Pb species. Arsenic existed mainly as As5+, scorodite (FeAsO4•2H2O)-like species in all the treatments ranging from about 60% (control) to about 70% (TAGRO plus ferrihydrite). Amendments utilizing both biosolids and Fh significantly reduce human exposure risks present in urban soils contaminated with Pb and As.
7

Alytaus miesto dirvožemio ir jame augančių želdinių būklės stebėsena / Monotoring of soil and greenery condition in Alytus town

Gerulienė, Gintarė 03 June 2011 (has links)
Miestai ypatingi žmogaus kūriniai, kuriose želdynai užima labai svarbią vietą. Nuo 2008 m. sausio 1 d. įsigaliojo Želdynų įstatymas (2008.01.14, Nr.D1-31), kurio programoje “Dėl želdynų ir želdinių būklės stebėsenos” numatyti uždaviniai ir jų sprendimo priemonės, siekiant surinkti duomenis ir kitą informaciją apie savivaldybei priskirtoje teritorijoje augančius želdynus ir želdinius, kad būtų galima tinkamai vertinti jų būklę, valdyti ir prognozuoti. To pasekoje, 2009 m. Alytaus miesto savivaldybės Aplinkos apsaugos skyrius paskelbtė konkursą ”Alytaus miesto želdynų ir želdinių būklės stebėsenos 2009–2013 metais parengimas ir vykdymas”. Šio darbo tikslas - įvertinti Alytaus miesto dirvožemio bei jame augančių želdinių būklę. Nustatyti dirvožemio pH, azotingumą, fosforingumą ir kalingumą bei techninės KCl druskos poveikį želdiniams. Želdinių būklės rodikliai – defoliacija, dechromacija, lapų nekrozės ir medžių kamienų pažeidimai vertinti penkių balų skalėmis nuo 1 iki 5, rugpjūčio – rugsėjo mėnesiais. Cheminių analizių duomenys rodo, kad Alytaus parkuose ir skveruose augantiems lapuočiams medžiams bei krūmams dirvožemio pH yra optimalus, t.y. pH 6,0–7,0, spygliuočiams dirvožemis galėtų būti rūgštesnis (optimalus pH 4,5–5,0). Judriųjų fosforo ir kalio kiekiai augalams yra nepakankami (<150 mg kg), išskyrus Angelų-Sargų Bažnyčios skverą, kuriame šių cheminių elementų kiekiai viršija pakankamą normą. Miesto gatvių želdinių dirvožemiai yra šarmiški (pH nuo 7,1 iki 7,8), o Pulko... [toliau žr. visą tekstą] / Cities are extraordinary creations of man, where greenery plays an important role. Since 2008 the Law on landscaping (01/14/2008, Nr.D1-31) came into effect. The program of landscaping and monitoring the plantation condition focuses on the collection of data, assessing, managing, predicting conditions and increasing the green areas and spaces in the territory of the municipality. As a result, in 2009 the Environmental Protection Department of the Alytus Municipality opened the contest for the preparation and monitoring of green spaces in Alytus city in 2009-2013. The aim of our research is to assess the quality of soil and green spaces in the city of Alytus, to determine the soil pH, the amount of nitrogen, phosphorus and potassium, as well as to assess the contamination of soil by sodium and chlorine. The defoliation, discolouration, necrosis of leaves and violation of tree trunks in the green spaces were evaluated on a of the five point scale from 1 to 5 in the period from August to September. Chemical analysis shows that the pH of soil is optimal for the deciduous trees and shrubs in parks and squares of Alytus city (pH 6.0-7.0), but it could be more acid as optimal pH is from 4.5 to 5.0. The amount of phosphorus and potassium in plants is not sufficient (<150mg kg), with the exception of Angels Church Square, where the amount of chemical elements exceeds the norm. The soil of urban street greenery is slightly alkaline (pH from 7.1 to 7.8), and in the Pulkas street the... [to full text]
8

Bioavailability of contaminants in urban soils

Attanayake, Chammi January 1900 (has links)
Doctor of Philosophy / Department of Agronomy / Ganga M. Hettiarachchi / Urban soils may contain harmful levels of potentially toxic contaminants. These contaminants transfer to humans via two exposure pathways: direct transfer (soil-humans by soil ingestion, dermal exposure and inhalation) and food chain transfer (soil-plant-humans). Soil amendments alter the speciation of the contaminants in soils and thereby modify their bioavailability. The objectives of this research were to access the plant availability of lead (Pb), arsenic (As), and polycyclic aromatic hydrocarbons (PAHs); bioaccessibility and speciation of soil Pb, and As; and dermal absorption of soil PAHs in contaminated urban soils; and effectiveness of soil organic amendments on reducing contaminant bioavailability. Two field experiments were conducted in Kansas City, MO and Indianapolis, IN. Both sites had elevated concentrations of Pb in soils (Kansas City site: 30-380 mg kg⁻¹ and Indianapolis site: 200-700 mg kg⁻¹) . Indianapolis site’s soils also had elevated concentrations of As (40-100 mg kg⁻¹) and PAHs (benzo[a]pyrene: 1-10 mg kg⁻¹) . A control treatment (no-compost) and compost-types (leaf compost and/or composted biosolids, non-composted biosolids, mushroom compost) were used as treatments. A leafy vegetable, a fruiting vegetable and a root crop were grown for two growing seasons. The treatments were arranged in split-plot design (main plot factor: compost; sub-plot factor plant-type). An in vitro steady fluid experiment was conducted using human skins to examine the dermal transfer of soil PAHs. The concentrations of Pb, As, and PAHs in the vegetables were low, except Pb in root crops. Compost reduced the bioaccessibility of Pb, but did not change the bioaccessibility of As. Selected soil samples were analyzed for speciation of Pb using extended x-ray absorption fine structure spectroscopy. The predominant Pb species were Pb sorbed to Fe oxy(hydr)oxide and to organic C. Stable Pb phosphates (pyromorphite) was formed during the in vitro extraction. Dermal transfer experiments showed PAHs in the contaminated soils did not transfer through the skin. Stratum conium of the skin acted as a barrier for dermal transfer of soil PAHs. In general, the risk of food chain transfer of soil Pb, As, and PAHs were low in the studied sites and can be further reduced by compost addition. Bioaccessibility of Pb and As in urban soils were low. Dermal absorption of soil PAHs was insignificant.
9

Sulfur Speciation in Urban Soils Studied by X-Ray Spectroscopy and Microscopy

Mathes, Mareike 14 May 2013 (has links)
No description available.
10

Development of a high pressure digestion technique and a data acquisition/reduction procedure and their application to the ICP-MS analysis of urban sediments and soils from Cebu, Philippines /

Diegor, Wilfredo G., January 1999 (has links)
Thesis (M.E.S.), Memorial University of Newfoundland, 1999. / Bibliography: p. 175-183.

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