Muddringsprojekt är en global företeelse och görs av flera olika anledningar, till exempel för miljömässiga aspekter och för breddning av farleder. För att få en hållbar utveckling är det viktigt att finna bra lösningar på frågan hur förorenade sediment skall hanteras . I Mälaren kommer olika muddringsprojekt att genomföras för att bredda farleden från slussen i Södertälje till hamnarna i Köping och Västerås. Muddringsprojekten skall genomföras av Sjöfartsverket, Köpings kommun och Västerås stad. En metod för att omhänderta muddermassorna är att stabilisera/solidifiera dem genom att blanda i ett bindemedel bestående av en blandning av cement, masugnsslagg och aktivt kol och låta dem härda. Detta görs för att förbättra materialets geotekniska egenskaper samt för att immobilisera föroreningar. Syftet med detta examensarbete var att undersöka om det går att använda krossade stabiliserade/solidifierade muddermassor ovan vattenytan till exempel i vägkonstruktioner alternativt som fyllnadsmaterial. Möjligheten för användandet av de stabiliserade/solidifierade materialet utvärderades genom att materialets geotekniska och miljömässiga egenskaper undersöktes. Den miljöpåverkan som de stabiliserade/solidifierade materialet skulle kunna ha på den omgivning där de används har undersökts genom analyser av totala föroreningshalter samtkoncentrationer vid lakning. Detta gjordes dels genom egna skakförsök och dels genom utvärdering av resultat från undersökningar som Statens geotekniska instituts (SGI)miljölaboratorium gjort. När det gäller materialets geotekniska egenskaper utvärderades resultat från undersökningar genomförda av SGIs geotekniska laboratorium. Stabiliseringen/solidifiering gjorde att de undersökta metallerna som förekommer som katjoner immobiliserades, vilket ledde till att lakningen minskade. Däremot fungerade imobiliseringen inte för anjoner; om det skulle ha förekommit höga halter av toxiska anjoner som till exemple arsenik, vanadin och molybden skulle dessa ha lakats ut. Ur ett miljömässigt perspektiv skulle det gå bra att använda det undersökta materialet då koncentrationen i lakvätskan låg under de båda gränsvärden som används; gränsvärden för inert avfall och gränsvärden för mindre än ringa risk vid användning av avfall för anläggningsändamål. När det gäller hållfasthet uppfyllde materialet efter 28 dagars härdning inte kraven som ställs för användning i vägkonstruktion. Däremot hade materialets geotekniska egenskaper förbättrats jämfört med de obehandlade sedimenten. / Dredging is a global phenomenon carried out for several different reasons, e.g. environmental remediation and expansion of shipping lanes. A sustainable solution to the problem of how contaminated sediment should be handled is thus important to achieve a more sustainable development. Several dredging projects will be implemented in the lake Mälaren to widen the shipping lane from the lock in Södertälje to the ports of Köping and Västerås. The dredging will be carried out as a joint effort by the Swedish Maritime Administration, the City of Västerås and Köping municipality. One method used for treating dredged sediments is stabilization/solidification. This is carried out to improve the geotechnical properties of the material and to immobilize contaminants. The method works as follows: Sediments are dragged form the lake, mixed with a binding agent consisting of cement, granulated blastfurnace slag and active carbon and then left to harden. The objective of this master thesis was to investigate the feasibility of using the stabilized/solidified material on land above the water surface. Examples of applications for the crushed material are in road construction or as fillers for vegetation surfaces. The stabilized/solidified material was evaluated with respect to environmental factors and geotechnical properties to determine if it was appropriate to use for these applications. To investigate the potential impact of the stabilized/solidified material on the surrounding environment, analysis of total contamination content and leaching tests were evaluated. In this thesis, batch-leaching tests for metals were performed as well as evaluation of lab results from surveys conducted in the environmental laboratory at the Swedish Geotechnical Institute. The geotechnical properties of the material were evaluated based on results from experimentsconducted by the geotechnical laboratory at the Swedish Geotechnical Institute. The results from the treatment with stabilization/solidification showed that most of the studied metals were immobilized, and the leaching of these metals decreased. From an environmental perspective it would be feasible to use the material, as the results of the leaching test were below the limit values used in the assessment; limits for inert waste and limits for less than small risk (‘mindre än ringa risk’) in use of waste for construction purposes. In terms of the geotechnical features, after 28 days of hardening the material did not meet the requirements for use in road construction. However, the material's geotechnical properties such as strength had improved compared to the untreated sediments.

Electronic waste or `e-waste' is a rapidly growing form of solid waste worldwide. The heavy metals present in various electronic components demand attention because such metals may leach and pose significant health and environmental hazards (U.S. EPA, 2007). Knowledge of the potential of heavy metal leaching from e-waste represents an important contribution for developing U.S. standards for classifying e-waste as hazardous waste. Hazardous elements which leach from a variety of electronics wastes were assessed in laboratory batch studies. Electronic components evaluated included PC cathode ray tubes, PC motherboards, PC mice, television remote controls, and cellular phones. Each component was disassembled and digested using the Toxicity Characteristic Leaching Procedure (TCLP), EPA Method 1312, Method EA NEN 7371 (Dutch Environmental Agency), and Method DEV-S4 (Germany). The extracts were analyzed for lead, cadmium, chromium, silver, and cobalt. The TCLP consistently leached the greatest amounts of all metals; TCLP-soluble lead was extracted well beyond federal limits for several electronic devices. / Department of Natural Resources and Environmental Management

The aim of this study was to determine the effects of the heavy metal pollution on microbial diversity along the gradient from a platinum mine tailings dam using culture-dependent (plating methods) and molecular methods. Tailings and soil samples were collected from seven sites (6 samples per site) at increasing distances from the tailings dam. Samples were collected over a two year period and included two rainy and two dry periods. Concentrations of various heavy metals were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The results demonstrated that seasonal variations in metal concentrations occurred and also that concentrations were significantly different'(P < 0.05) between the experimental sites for each metal. The relative relationship between metals was in the following order: Al > Ni > Cu > Cr. Since soil metal concentration benchmarks for South Africa are lacking, the concentrations were compared to the Canadian microbial benchmarks (MB) and Netherlands maximum permissible concentrations (MPC). Concentrations of most of the heavy metals exceeded the MB and MPC. Levels and diversity of culturable fungi and bacteria at each site were determined using plate count methods. Results indicated that levels of bacteria and fungi were not suppressed by high concentrations of heavy metals. Significantly higher levels (P < 0.05) of fungi were found at the sites on the tailings dam (higher concentrations of heavy metals), compared to sites more than 300 m away. A commonly used soil health index (Shannon-Weaver diversity index) was used to compare microbial community diversity at each site and to evaluate whether or not the heavy metal contamination impacted negatively on these soil bacterial and fungal communities. Shannon-Weaver diversity indices were higher at sites on and close to the tailings dam than sites more than 300 m away. However, ratio of fungal to bacterial levels as determined by plate counts was inconsistent. Representatives of bacterial species that were grouped using colony morphology and whole cell protein profiles were identified by 16S rDNA sequences as Bacillus barbaricus (B. barbaricus) and -Paenibacillus lautus {P. Lautus). Restriction enzyme digest, SDS-PAGE and random amplified polymorphic DNA (RAPD) analyses provided supporting evidence that representatives were correctly grouped. Cluster analysis results demonstrated that the RAPD profiles of the metal tolerant P. lautus representatives were sufficiently dissimilar to discriminate between individuals from the spatially separated sites. The spatially separated sites also represented sites with high and low heavy metal concentrations. Observed genetic variability was thus also associated with varying levels of heavy metals. In conclusion, this study demonstrated the potential of using RAPD analysis as biomarkers for genotoxic effects of heavy metals on bacterial genomes. / Masters / Thesis (M.Sc. (Microbiology))--North-West University, Potchefstroom Campus, 2009.

The aim of this study was to determine the effects of the heavy metal pollution on microbial diversity along the gradient from a platinum mine tailings dam using culture-dependent (plating methods) and molecular methods. Tailings and soil samples were collected from seven sites (6 samples per site) at increasing distances from the tailings dam. Samples were collected over a two year period and included two rainy and two dry periods. Concentrations of various heavy metals were determined using an inductively coupled plasma mass spectrometer (ICP-MS). The results demonstrated that seasonal variations in metal concentrations occurred and also that concentrations were significantly different'(P < 0.05) between the experimental sites for each metal. The relative relationship between metals was in the following order: Al > Ni > Cu > Cr. Since soil metal concentration benchmarks for South Africa are lacking, the concentrations were compared to the Canadian microbial benchmarks (MB) and Netherlands maximum permissible concentrations (MPC). Concentrations of most of the heavy metals exceeded the MB and MPC. Levels and diversity of culturable fungi and bacteria at each site were determined using plate count methods. Results indicated that levels of bacteria and fungi were not suppressed by high concentrations of heavy metals. Significantly higher levels (P < 0.05) of fungi were found at the sites on the tailings dam (higher concentrations of heavy metals), compared to sites more than 300 m away. A commonly used soil health index (Shannon-Weaver diversity index) was used to compare microbial community diversity at each site and to evaluate whether or not the heavy metal contamination impacted negatively on these soil bacterial and fungal communities. Shannon-Weaver diversity indices were higher at sites on and close to the tailings dam than sites more than 300 m away. However, ratio of fungal to bacterial levels as determined by plate counts was inconsistent. Representatives of bacterial species that were grouped using colony morphology and whole cell protein profiles were identified by 16S rDNA sequences as Bacillus barbaricus (B. barbaricus) and -Paenibacillus lautus {P. Lautus). Restriction enzyme digest, SDS-PAGE and random amplified polymorphic DNA (RAPD) analyses provided supporting evidence that representatives were correctly grouped. Cluster analysis results demonstrated that the RAPD profiles of the metal tolerant P. lautus representatives were sufficiently dissimilar to discriminate between individuals from the spatially separated sites. The spatially separated sites also represented sites with high and low heavy metal concentrations. Observed genetic variability was thus also associated with varying levels of heavy metals. In conclusion, this study demonstrated the potential of using RAPD analysis as biomarkers for genotoxic effects of heavy metals on bacterial genomes. / Masters / Thesis (M.Sc. (Microbiology))--North-West University, Potchefstroom Campus, 2009.

This thesis investigates the potential advantage of using remote sensing techniques to assess underground transmission tower corrosion. The data used in this study was collected from three electrical transmission towers in the Lower Fraser Valley, British Columbia, Canada. A comprehensive assessment of the corrosive environments have included the following factors: climate, soil pH, soil moisture content, soil resistivity, overlying plant spectral reflectance, and heavy metal content in soil and vegetation. The principal method of protection against steel tower corrosion is zinc galvanization. As zinc serves as a sacrificial coating, once corroded, it leaches into the soil, and is then absorbed by surrounding vegetation. High concentrations of heavy metals may negatively influence plant growth. Plant Root Simulator (PRS™) probes were used to assess heavy metal supply rates by continuously adsorbing charged ionic species while in soil. Heavy metal content analysis was also conducted on sampled tower vegetation using an Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). Remote sensing techniques, such as field spectroscopy, have great potential for monitoring spectral reflectance variations of various vegetation types and biophysical characteristics. The energy-matter interactions in the UV, VIS, NIR and IR wavelength regions can be used for chemical analysis of compounds and mixtures. The combination of remote sensing analysis techniques, such as NDVI, leaf structural index R110/R810, water content index R900/R970, first order derivative analysis, and continuum removal can provide non-intrusive and continuous monitoring methods for the impact and content of certain heavy metals in plants growing in contaminated soils. However, in this study, the high zinc concentrations recorded from the PRS™-probes and ICP-AES could not be correlated to the reflectance spectra measured by the field spectrometer. Although using zinc as a spectral corrosion identifier was not successful in this thesis, the presence of a chemical process in which by-products were produced and leached into the soil was evident. The integration of remote sensing techniques and underground corrosion explored in this thesis presents unique opportunities for further research in this area of study.

A seven-step sequential extraction scheme was used to track changes in operationally defined copper speciation during the composting of a mixture of grass clippings and sawdust originating from tanalised timber. Starting materials were either unamended or treated with differing amounts of soluble copper, using a copper acetate solution, and then composted in the laboratory. Results showed that at the start of the experiment over 80% of the copper present in the unamended materials occurred in forms not immediately available for plant uptake. However, composting processes enabled the release of this copper which then, over time, became more bioavailable. Large amounts of copper in the copper amended materials were initially detectable in all fractions except the residual one, but over time it was seen to move from all fractions to the EDTA extractable fraction, thought to determine organically complexed / chelatable metals (Amir, 2005). This continued until an equilibrium was reached and then the water and calcium nitrate extractable forms appeared to hold the excess. Copper as determined by these extracts would be available for plant uptake. In the second experiment, three different organic wastes (grass/sawdust, pig slurry/sawdust and sewage sludge cake/sawdust) to which copper had been added as copper acetate, sulphate or EDTA, were composted in the laboratory. Samples were taken at 0, 105 and 318 days and subjected to a range of analyses: copper by sequential extraction using two different extraction schemes, a chelating resin membrane (CRM) procedure and by XRF spectrometry; FTIR analysis for functional groups; total carbon, nitrogen and sulphur; pH, EC, NH4+ and NO3- nitrogen, COD, germination indices and optical properties of water extracts. Sequential extractions demonstrated clear changes in copper distribution amongst various fractions within the materials, with copper originally present in the materials being transferred from the oxidisable fractions to easily extractable (and hence potentially phytoavailable) fractions. Transfer of copper from available to less available fractions in copper amended materials was also seen with movement of copper within copper EDTA treated materials being the slowest of all. Initial amounts of copper in fraction 1 extracted from all samples determined the rate at which copper was transformed. CRM determined copper correlated strongly with copper from fraction 1 of the Tessier scheme, although changes over time did not correspond well. Other parameters measured indicated that that the material was maturing (decreases in C/N and polysaccharide functional groups). However, other results demonstrated that the composts were still immature and unstable. Such slow decomposition was attributed to the high lignin content of the materials. Nevertheless, immobilisation of potentially phytotoxic level of copper was still demonstrated. The usefulness of chelating resin membrane as a predictor of phytoavailable copper is also discussed.

The extensive medical and agricultural use and misuse of antibiotics during the last 70 years has caused an enrichment of resistant pathogenic bacteria that now severely threatens our capacity to efficiently treat bacterial infections. While is has been known for a long time that high concentrations of antibiotics can select for resistant mutants, less is known about the lower limit at which antibiotics can be selective and enrich for resistant bacteria. In this thesis we investigated the role of low concentrations of antibiotics and heavy metals in the enrichment and evolution of antibiotic resistance. Selection was studied using Escherichia coli and Salmonella enterica serovar Typhimurium LT2 with different resistance mutations, different chromosomal resistance genes as well as large conjugative multidrug resistance plasmids. Using very sensitive competition experiments, we showed that antibiotic and heavy metal levels more than several hundred-fold below the minimal inhibitory concentration of susceptible bacteria can enrich for resistant bacteria. Additionally, we demonstrated that subinhibitory levels of antibiotics can select for de novo resistant mutants, and that these conditions can select for a new spectrum of low-cost resistance mutations. The combinatorial effects of antibiotics and heavy metals can cause an enrichment of a multidrug resistance plasmid, even if the concentration of each compound individually is not high enough to cause selection. These results indicate that environments contaminated with low levels of antibiotics and heavy metals such as, for example, sewage water or soil fertilized with sludge or manure, could provide a setting for selection, enrichment and transfer of antibiotic resistance genes. This selection could be a critical step in the transfer of resistance genes from environmental bacteria to human pathogens.

Sunkieji metalai yra vieni toksiškiausių ir žalingiausių aplinkos veiksnių. Organizme jie skatina aktyviųjų deguonies formų susidarymą, dėl to pažeidžiamos ląstelės membranos, nukleorūgščių ir baltymų struktūros. Šiame darbe ištyrime sunkiųjų metalų Pb ir Ni toksinį poveikį kepenų antioksidacinei apsaugos sistemai, baltymų sintezės (transliacijos) sistemai bei antioksidanto Zn apsauginį veikimą prieš toksinį Pb ir Ni poveikį. Įvertinome kompleksinį šių metalų jonų poveikį oksidacinio streso rodikliui – redukuoto glutationo koncentracijai, lipidų peroksidacijai, bendro baltymo, apsauginio baltymo metalotioneino, bei hemo sintezei. Nustatėme, kad Zn jonai geba apsaugoti ląstelę nuo toksinio Pb ir Ni jonų poveikio, tačiau jų apsauginis poveikis yra nevienareikšmiškas. Parodėme, kad Zn jonai apsaugo ląsteles nuo Pb jonų sukeltų oksidacinių pažeidimų ankstyvoje intoksikavimo stadijoje. Tačiau, šio metalo apsauginį poveikį prieš Ni jonų toksiškumą nustatėme tik po dviejų savaičių. Šis darbas leidžia detaliau suprasti Zn pajėgumą apsaugoti organizmą nuo toksinio Pb ir Ni poveikio. / Heavy metals are among the most toxic and harmful environmental factors. In the body, they promote the formation of active oxygen species, resulting the damage to the cell membranes, nucleic acid and protein structure. This study was conducted to evaluate the toxic effects of Pb and Ni on antioxidant defence and protein synthesis (translation) systems in liver cells and to determine the possible protective effect of Zn against Pb and Ni toxicity. We established the complex effect of these metal ions on the content of an oxidative stress marker reduced glutathione, lipid peroxidation as well as on total protein, metallothionein and heme synthesis. It was determined that Zn ions are able to pro¬tect cells from the toxic effects of Pb and Ni ions exposure, but the protective effect was ambiguous. The Zn ions protected cells from Pb ions induced oxidative damage in the early stages of intoxication. The protective effect against Ni ions toxicity, on the contrary, was observed only after two weeks of intoxication. This study provides more detailed understanding of Zn ability to pro¬tect the organism from toxic effects of Pb and Ni.

Tikslas: įvertinti sunkiųjų metalų koncentracijų pasiskirstymą paprastosios jonažolės mineralizate, vandeninėse ir etanolinėse ištraukose bei jų sąveiką su taninais. Uždaviniai: nustatyti ir palyginti cinko ir vario koncentracijas paprastosios jonažolės mineralizatuose bei vandeninėse ištraukose; nustatyti ir palyginti kadmio ir švino koncentraciją paprastosios jonažolės mineralizatuose, vandeninėje bei etanolinėje ištraukose; palyginti sunkiųjų metalų koncentracijų pasiskirstymą skirtingose Lietuvos Respublikos vietovėse, įvertinti paprastosios jonažolės mineralizate esančio sunkiojo metalo (švino) sąveiką su taninais. Buvo vykdoma drėgna mineralizacija Multiwave 3000 mineralizatoriumi (HNO3 + HCl + H2O2). SM koncentracijos mineralizatuose, vandeniniuose ir etanoliniuose tirpaluose buvo nustatytos Perkin Elmer Zeeman 3030 atominiu spektrofotometru. Cinko koncentracijos vidurkis mineralizatuose – 21,49 µg/g, o vandeninėse ištraukose- 15,92 µg/g (p<0,05). Vario koncentracijos vidurkis mineralizatuose - 11,22 µg/g, o vandeninėse ištraukose ji beveik 2 kartus mažesnė (p<0,05). Kadmio koncentracijos vidurkis mineralizatuose - 0,12 µg/g, vandeninėse ištraukoje jis daugiau nei 5 kartus mažesnis, o etanolinėse ištraukose - 0,003 µg/g, skirtumai yra statistiškai reikšmingi (p<0,05). Švino koncentracijos vidurkis mineralizatuose yra 0,46 µg/g, vandeninėse ištraukose - beveik 7 kartus mažesnis, o etanolinėse ištraukose jis lygus 0,05 µg/g, skirtumai yra statistiškai reikšmingi (p<0... [toliau žr. visą tekstą] / Purpose: To assess concentrations of heavy metals in mineralizates, ethanolic and aqueous extract of St. John's wort and their interactions with tannins. Objectives: to determine and compare the concentrations of zinc and copper in mineralizates and aqueous extracts of St. John's Wort; to determine and compare the concentrations of cadmium and lead in mineralizates, aqueous and ethanolic extracts of St. John's Wort; to compare concentrations of heavy metals in herbal raw material, collected in different areas of the Republic of Lithuania; to evaluate heavy metal (lead), which is in the mineralizate of St. John's wort, interactions with tannins. The wet mineralization using Multiwave 3000 mineralizator (HNO3 + HCl + H2O2) was applied. Heavy metals concentrations i mineralizates, aqueous and ethanolic solutions were determined Perkin Elmer Zeeman 3030 atomic spectrophotometer. The average zinc concentration was 21.49 µg/g in the mineralizates, 15.92 µg/g in the aqueous extracts (p<0,05). The average copper concentration was 11.22 µg/g in the mineralizates and it was almost 2 times lower in the aqueous extracts (p<0,05). Average cadmium concentration was 0.12 µg/g in the mineralizates and more than 5 times lower in the aqueous extracts; 0.003 µg/g average concentration of cadmium was found in the aqueous extracts, these differences are statistically significant (p<0,05). Average lead concentration was 0.46 µg/g in the mineralizates and it was almost 7 times lower in... [to full text]

In the summers 1997, 1998 and 1999, over 100 aquatic invertebrate kick samples were collected in the Northwest Miramichi River of northeastern New Brunswick to examine the effects of chronic heavy metal exposure on the aquatic predatory Plecoptera community. In the group of predators, Neoperla (Plecoptera) was numerically dominant and gut content identifications were used to determine food chain and life cycle stages. Neoperla diet analysis indicated the Chironomidae (Diptera) as the dominant prey with predation upon Trichoptera and Ephemeroptera influenced by the life cycle stage of the predator. Gut content totals were analysed for predatory diet changes due to heavy metal contamination exposure. The Neoperla community indicated a prey shift from a Chironomidae based diet to one including a higher percentage of Ephemeroptera and Trichoptera earlier in the predators life history when compared with upstream control sites. Neoperla diets maintained their shift from the control station diets as the downstream movement of heavy metal contaminated water mixed and dissipated within the study area.