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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.
31

DNA barcoding of different earthworms' species and their response to ecotoxicological testing / Laetitia Voua Otomo

Voua Otomo, Laetitia January 2015 (has links)
The ecotoxicological literature reveals that countless researchers worldwide rely upon informally identified commercial earthworm stocks for laboratory bioassays. The primary aim of this study was to investigate laboratory and commercial stocks of Eisenia species used in South Africa in order to confirm their taxonomy, assess their levels of genetic richness and differentiation. To do so, populations of potential Eisenia andrei and Eisenia fetida were purchased/obtained from vermiculturists and laboratories from four provinces of South Africa. DNA barcoding was used to investigate these taxonomic uncertainties. The COI gene was partially amplified and sequenced in selected earthworms from eight local populations (focal groups) and two European laboratory stocks (non-focal groups). Only nine COI haplotypes were identified from the 224 sequences generated. One of these haplotypes was found to belong to the Megascolecidae Perionyx excavatus. The remaining eight haplotypes belonged to the genus Eisenia although only a single Eisenia fetida haplotype, represented by six specimens, was found in one of the European populations. The other seven haplotypes, all occurring in South Africa, were Eisenia andrei. No Eisenia fetida was found in the South African based populations. One of the commercial stocks from South Africa and a laboratory culture from Europe were mixes of E. andrei - P. excavatus and E. andrei – E. fetida respectively. COI haplotype numbers were limited to two to three distinct sequences within each of the local groups. This translated into a haplotype diversity (H) lower than 0.45 in all the populations, which is very low when compared to other such earthworm studies in which COI polymorphism has been investigated. Of all the local populations investigated, only the lone field population included was genetically divergent from the other populations. This was explained by the haplotype distribution across the populations which indicated that this population was the only one not harbouring the haplotype which represented 75% or more of the COI sequences within the local populations. Because research suggests that earthworm populations with limited genetic diversity may suffer inbreeding depression which could affect traits such as reproduction and survival, the secondary aim was to test whether metal-sensitive earthworms were overly present in the populations investigated. To do so, the three most common COI haplotypes identified between the 8 local populations of E. andrei (called Hap1, Hap2 and Hap3) were paired up and exposed to cadmium. A total of six couples were exposed to 0, 25, 50 and 100 mg Cd/kg for 4 weeks at 20ºC. The survival, biomass variation, cocoon production and cocoon hatching success were assessed for all the couples. The results indicated that couple 6 (Hap3xHap3) was the most sensitive for three of the endpoints assessed whereas couple 4 (Hap1 x Hap3) was the least sensitive. Cocoon hatching success could not help differentiate the couples. The analysis of Cd tissue contents revealed that with increasing Cd concentration, Cp6 (Hap3xHap3) could accumulate significantly more Cd than any other couple (p ≤ 0.01). These findings indicate that earthworm populations may carry intrinsically metal-tolerant and metal-sensitive genotypes. In the context of ecotoxicological testing, the present results underline the importance of using genetically diverse populations in laboratory testing as Cp6 (Hap3xHap3) could have suffered from the deleterious effect of inbreeding. Because E. fetida could not be found in the local populations assessed, it is recommended that further earthworm DNA barcoding studies, covering a more representative geographical area of South Africa and including more field populations of Eisenia spp. be conducted. Because of the occurrence of genetic homogeneity in the populations studied, it is suggested that captive breeding initiatives be established using specimens obtained from several geographically distant field and reared populations. Further research investigating patterns of Cd accumulation/excretion kinetics between the Cd-tolerant and Cd-sensitive individuals reported in the present study, should be conducted to help determine whether inbreeding is the sole factor explaining the observed genotypic responses to Cd. Finally, the necessity of a standardised earthworm barcoding protocol that could help both to properly identify laboratory earthworm stocks and to select genetically diverse stocks suitable for laboratory testing, is discussed together with the relevance of the present work to ecotoxicological testing in general. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2015
32

Application of Different Measures of Bioavailability at Contaminated Sites

Smith, Benjamin January 2009 (has links)
Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.
33

Application of Different Measures of Bioavailability at Contaminated Sites

Smith, Benjamin January 2009 (has links)
Contaminated areas resulting from anthropogenic activities have, for the most part, concentrations of contaminants that exceed Tier 1 standards below which the risk is considered acceptable. However, contaminants that have been in soil for a prolonged period can become recalcitrant over time, due to various physico-chemical and biological processes. Sequestered and recalcitrant contaminants are not readily biologically available to living organisms. However, they are easily measured analytically because of the strong acid extractions that are used in the analytical methodologies. Because toxicity is a function of exposure concentration(s), exposure duration, and bioavailability, contaminants in soil can be present at concentrations that exceed established standards but they represent minimal risk to ecological receptors because the contaminants are not fully available. To predict toxicity and estimate risk, it is imperative that an accurate and reliable measure of bioavailability be available. Several surrogate measures of bioavailability were compared to the results of a battery of toxicity tests using Cu, Pb, and Zn-contaminated soils collected from a former industrial area and Cu and Zn-contaminated soils collected from a former mining site. CaCl₂extractions, hydroxypropyl-β-cyclodextrin (cyclodextrin) extractions, Simulated Earthworm Gut (SEG) tests, and bioaccumulation tests were performed using the soils. Overall, SEG-extractable Cu was most predictive of adverse effects in industrial soils, likely due to enzymatic activity and/or increased ionic strength of the solution. For the mining soils, all chemical measures of bioavailability correlated with several biological responses; however, CaCl₂-extractable Cu and SEG-extractable Cu and Zn best predicted earthworm responses. Total Cu concentrations in soil correlated best with adverse effects to plants. No method was a good predictor of all biological effects for a single organism when data from the two sites were combined. The SEG test may provide a good indication of metal toxicity at contaminated sites with varying soil physico-chemical characteristics but further validation is required.
34

Desinfecção de lodo de esgoto por meio de vermicompostagem. / Disinfection of sewage sludge by means of vermicomposting.

SILVA, Clenilson Ferreira da. 15 June 2018 (has links)
Submitted by Élida Maeli Fernandes Quirino (maely_sax@hotmail.com) on 2018-06-15T19:50:05Z No. of bitstreams: 1 CLENILSON FERREIRA DA SILVA - DISSERTAÇÃO PPGEA 2004..pdf: 17082584 bytes, checksum: a09a08f2e0b07031cb1ef45f2c5c6b73 (MD5) / Made available in DSpace on 2018-06-15T19:50:05Z (GMT). No. of bitstreams: 1 CLENILSON FERREIRA DA SILVA - DISSERTAÇÃO PPGEA 2004..pdf: 17082584 bytes, checksum: a09a08f2e0b07031cb1ef45f2c5c6b73 (MD5) Previous issue date: 2004-09 / Este trabalho teve, como objetivo a desinfecção do lodo anaeróbio oriundo de Digestores Anaeróbio de Fluxo Ascendente (DAFA), instalado no PROSAB/ Campina Grande-Pb, através da vermicompostagem com minhocas vermelhas da Califórnia. O experimento foi realizado durante o período de junho a outubro de 2002. O delineamento foi em blocos inteiramente causalizados, em esquema fatorial [(3 x 2) + 1], representado por três umidades (60, 70 e 80%) e dois compostos de lodo (lodo anaeróbio e lodo anaeróbio+bagaço de cana-de-açúcar), mais uma testemunha: absoluta (lodo anaeróbio a 85%), com quatro repetições. Após a desidratação do lodo anaeróbio. A vermicompostagem promoveu a remoção dos coliformes fecais em todos os tratamentos aplicados. Para os helmintos, a maior redução foi obtida quando da utilização do substrato sem bagaço de cana-de-açúcar, já em relação ao teor de umidade, a maior redução de helmintos foi conseguida a uma umidade de 70%. Quanto ao teor de metais pesados determinados nas amostras do vermicomposto, ficaram muito abaixo do máximo permissível para uso agrícola do lodo (USEPA, 1992). Observou-se também que, ao final do experimento a produtividade da Eisenia fétida (minhoca vermelha da Califónia) foi bastante satisfatório em alguns tratamentos. / This vvork had, as objective the disinfection of the anaerobic mud originating frora of Anaerobic Digestores of Ascending Flow (DAFA), installed in PROSAB / Campina Grande-Pb, through the vermicompostagem with red earthworms of Califórnia. The experiment was accomplished during the period of June to October of 2002. The delineamento was in blocks entirely causalizados, in factorial outline [(3 x 2) + 1], acted by three humidities (60, 70 and 80%) and two composed of mud (anaerobic mud and mud sugarcane anaeróbio+bagaço), one more witness: absolute (anaerobic mud to 85%), with four repetitions. After the dehydration of the anaerobic mud. The vermicompostagem promoted the removal of the fecal coliformes in ali of the applied treatments. For the helmintos, the largest reduction was obtained when of the use of the subsrratum without sugarcane pulp, already in relation to the humidity tenor, the largest helmintos reduction was gotten her/it a humidity of 70%. as for the tenor certain metais in the samples of the vermicomposto, they were a lot below the permissible maximum for agricultural use of the mud (USEPA, 1992). it was also Observed that, at the end of the experiment the productivity of fetid Eisenia (red earthworm of Califónia) it was quite satisfactory in some treatments.
35

Upptag av polycykliska aromatiska kolväten från olika kontaminerade jordar i daggmask (Eisenia Fetida)

Axdorff, Louise January 2017 (has links)
Många antropogena ämnen är toxiska och har lång halveringstid och återfinns därför lång tid efter att de hamnat i miljön. Ett exempel är polycykliska aromatiska kolväten (PAH), som bildas vid ofullständig förbränning av organiskt material och som kan förekomma i höga halter vid före detta gasverk och gamla träimpregneringsplatser där kreosotimpregnering förekommit. I marken på dessa områden kan halterna av PAH vara mycket höga, och det kan påverka markekosystemet negativt. En viktig markorganism är daggmask, som har stor betydelse i många markekosystem. Därför är det viktigt att veta om PAHer i mark är tillgängliga för upptag i mask, eftersom det kan påverka masken negativt. Dessutom skulle eventuella PAHer i mask kunna transporteras vidare i näringskedjor. Syftet med studien var därför att undersöka upptaget av polycykliska aromatiska kolväten (PAH) i Eisenia Fetida från förorenad jord. E. Fetida exponerades under två veckor för nio olika PAH-förorenade jordar som samlats in från två kreosotförorenade områden, en före detta gasverkstomt och en bangård. Sammanlagt 24 PAHer inklusive PAH16 analyserades i jord och mask med GC/MS. Resultaten visade upptag av PAHer i E. Fetida från samtliga jordprov, men upptaget varierade beroende på prov. Ett jordprov från en före detta gasverkstomt, gasverk c hade den högsta uppmätta totala bioackumuleringsfaktorn (BAF) för PAHer från respektive prov. De enskilda BAF-värdena i jorden var högre för de högmolekylära PAHerna, medan jordprov insamlade på en bangård visade på ett högre upptag i mask av de låg- och mellan molekylära PAHerna. Ett av de kreosotförorenade jordproverna, kreosot a hade det högsta enskilda BAF-värdet för PAHer, vilket var trifenylen som hade en BAF 18.Det var inget signifikant samband mellan PAH-halten i jordarna och PAH-halten i mask, vilket tyder på att upptaget i mask inte enbart beror på halten PAHer i jorden. Det var heller inget signifikant samband mellan halten organiskt material och upptaget av PAHer i E. Fetida, men resultaten tyder på att upptaget i E. Fetida beror mer på jordegenskaper som organiskt material än halterna av PAHer i jorden. Det är därför viktigt att fortsätta forska kring PAHer och biotillgänglighet i mark.
36

Toxicity of Polychlorinated Biphenyls (Aroclor 1254) on the Earthworm Eisenia foetida

Sassani, Ramin 08 1900 (has links)
Objectives were to: (1) assess toxicity of polychlorinated biphenyls on Eisenia foetida, in terms of survival (LC5O/LD5O), and suppression of coelomocytes to form secretory (SR) and erythrocyte rosettes (ER) with, and to phagocytize rabbit erythrocytes; and (2) compare results with those of Lumbricus terrestris to assess relative sensitivities to PCB. Using 5-d filter paper contact exposure protocol, LC50 and LD50 were 30.4 cg/cm2 and 4450 cg/g dry mass, respectively. Nominal PCB exposure concentrations of 5.0 and 10.0 pg/cm2 resulted in tissue levels of 1389 and 2895 pg/g dry mass causing a significant reduction in SR formation by 18 and 52%, respectively. ER formation and phagocytosis were reduced significantly (52 and 61%) only at the higher tissue concentration. Compared to reported data on lethality and immunomodulation in L. terrestris, E. foetida appears to be more resistant.
37

Využití testů s destruenty pro ekotoxikologické hodnocení kvality půd / Using tests with destruents for ecotoxicological evaluation of soil quality

Rábová, Petra January 2020 (has links)
The aim of this diploma thesis was to determine the dehydrogenase activity of matrix samples that can enter the environment and the use of ecotoxicological tests to assess the quality of the affected soil. The effects of sludge, biochar samples, two landfill samples and a sediment sample were monitored. Ecotoxicology included tests on decomposers - tests of avoidance behavior (Eisenia fetida and Folsomia candida), acute, chronic and reproductive toxicity tests (Eisenia fetida) and Lactuca sativa root growth inhibition tests. The results indicate that dehydrogenase activity assays serve as a suitable complement to ecotoxicological tests. They provide valuable additional information on soil quality and sample effect after application to soil. The sediment sample had the least favorable effect on the activity of the enzyme and the vitality of the organisms, both in the determination of dehydrogenase activity and in ecotoxicological tests. Furthermore, it was found that biochar as a product of sewage sludge treatment is less toxic to organisms than the original sludge.
38

Využití vybraných testů ekotoxicity na organismu Eisenia fetida při hodnocení kontaminace ekosystému vybranými léčivy. / Use of selected toxicity tests on organisms Eisenia fetida in assessing ecosystem contamination by selected drugs.

Kašpárková, Petra January 2014 (has links)
Constantly increasing consumption of drugs leads to the increase of the concentration of residues in various environmental compartments. For this reason the drug residues are nowadays classified as significant environmental contaminants. The drug residues enter the soil along with the application of sewage sludge either as a fertilizer or during fertilizing by animal excrements excreted after drug administration, eventually by direct contamination from treated grazing animals. The presence of these substances in soil has got negative impact on the sensitive soil ecosystem. The diploma thesis aims to evaluation of possible soil contamination with selected drugs through ecotoxicity tests. For this purpose sulfonamide chemotherapeutic agents, which are often used in veterinary medicine, were chosen, specifically sulfamethoxazole and sulfamethazin. Eartworms (Lumbricus) were selected as suitable test representative soil organism. In the experimantal part of this work the avoidance test according to ISO 17512-1 and modified bioaccumulation test according to OECD 317 methodology were performed. Bioaccumulation substances in oligochaetes, for which the artificial soil was prepared according to OECD 207 methodology, which was subsequently contaminated with above specified drugs. Although according to the results of determination of these substances there is no significant bioaccumulation in eartworms‘ tissue, these organisms are very responsive to the presence of contaminants in the soil environment. This is evident from the results of avoidance tests.
39

Incorporating Ground Beetle (Coleoptera: Carabidae) Assemblage Data and Earthworm Bioassays in the Ecological Risk Assessment of a Trap and Skeet Shooting Range

Bryant, Joshua Lee 03 September 2010 (has links)
No description available.
40

Traitement et valorisation des sous-produits oléicoles par compostage et lombricompostage / Treatment and recovery of olive byproducts by composting and vermicomposting

Kharbouch, Barhoum 17 April 2018 (has links)
L'industrie oléicole joue un rôle socio-économique important pour les pays méditerranéens. Cependant, ce secteur pose également de sérieux problèmes environnementaux dus à la production de grandes quantités de sous-produits pendant de courtes périodes : les grignons d'olive, les margines (effluents liquide) et les margions. En effet, les margines représentent un défi environnemental majeur. Face à cette situation, plusieurs techniques physico-chimique et biologique ont été développées pour répondre à cette problématique. Malgré leur efficacité, ces techniques présentent l’inconvénient d’être chères. L'objectif de ce travail est de contribuer à la gestion et la valorisation à grande échelle des sous-produits oléicoles à travers l’optimisation des paramètres de démarrage du processus, le compostage et le lombricompostage et de mettre au point une méthode simple et efficace de suivi de l’évolution chimique et biologique des composts. Notre étude a porté sur le lombricompostage et le compostage d’un mélange de grignons d’olive, de fumier de cheval et de paille de blé, imbibé avec un ajout de margines à différentes concentrations. Le compost et le vermicompost ont été caractérisés par des paramètres physico-chimiques et biologiques qui ont mis en évidence la minéralisation, l’humification et la stabilisation de la matière organique. Le lombricompostage, combiné au compostage, peut être une technique adaptée et moins couteuse pour le traitement et la valorisation des sous-produits oléicoles comme amendement organique à grande échelle. / The olive industry plays an important socio-economic role for the Mediterranean countries. However, this sector also caused serious environmental problems due to the production of large quantities of by-products for short periods: olive pomace, olive mille wastewater (OMWW) and tow phase olive waste. Indeed, OMWW represent a major environmental challenge because of their chemical composition. Faced with this situation, several physicochemical and biological techniques have been developed to respond to this problem. Despite their effectiveness, these techniques have the disadvantage of being expensive. The objective of this study is to contribute to the management and the large-scale valorization of olive oil by-products through the optimization of the starting parameters of the process; composting and vermicomposting and to develop a simple and effective method for monitoring the chemical and biological evolution of composts. Our study focused on vermicomposting and composting a mixture of olive pomace, horse manure and wheat straw, soaked with the addition of OMWW at different concentrations. Compost and vermicompost were characterized by physicochemical parameters and biological parameters which showed the mineralization, humification and stabilization of organic matter.Vermicomposting, combined with composting, may be a suitable and less expensive technique for the processing and valorization of olive oil by-products as a large-scale organic amendment.

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