La phytoremédiation s’impose depuis peu comme une alternative de décontamination des sols accessible et soucieuse de l’environnement. Le projet présenté ici a permis de tester, en serre, un traitement sur des sols modérément contaminés aux éléments traces (ET) (Cd, Cu, Pb et Zn), et comportant deux niveaux de contamination organique. L’étude, imbriquée au projet Génorem, a été réalisée à l’aide de plants de Salix purpurea et de mycorhizes Glomus irregulare. Les objectifs étaient 1) d’étudier l’effet de la présence des mycorhizes introduites sur le processus d’absorption des ET, ainsi que l’efficacité générale du traitement ; 2) de déterminer l’influence des processus de transfert et de mise en solution des ET au sein de la rhizosphère sur leur taux d’accumulation par les plantes, et 3) de mesurer l’impact des caractéristiques des sols et de la contamination organique sur la phytoextraction. La présence des mycorhizes inoculées n’a été perceptible ni sur l’accumulation et le transfert des ET, ni sur la production de biomasse. Seules les concentrations solubles de Cu et de Pb se sont avérées moins importantes dans la rhizosphère des sols inoculés que dans la matrice de sol. La performance des plants quant à leur niveau d’accumulation s’est avérée intéressante pour le Cd (moyennes de 2,80 à 10,1 mg/kg) et le Zn (de 54,1 à 410 mg/kg). Ces éléments se sont accumulés surtout dans les parties aériennes des plantes, alors que le Cu et le Pb ont plutôt été stockés dans les racines. Les concentrations solubles avaient pour la plupart augmenté entre le début et la fin de l’expérience, et les différences entre ces concentrations et les concentrations totales, dans la rhizosphère et la matrice, ont démontré que le temps de réponse du sol pour fournir aux plantes les éléments biodisponibles n’était pas un facteur limitant du système dans la plupart des cas. Les concentrations initiales totales dans les sols ont été corrélées à celles dans les parties des plantes uniquement pour le Cu dans les tiges (R2 : 0,54) et les racines (R2 : 0,58) des saules. Les facteurs de fertilité ont permis d’expliquer une part de la variance des concentrations (10 % du total de 25 % pour le Cd, 49 % du total de 36 % pour le Cu-aérien, et 28 % du total de 71 % pour le Cu-souterrain) et des quantités (15 % du total de 30 % pour le Cd) accumulées. La contamination mixte (organique et inorganique) n’a pas entravé l’extraction des ET, ni la dégradation des composés organiques. / Phytoremediation is a relatively new, low cost and environmentally friendly alternative method to decontaminating soils. This research, which involved Salix purpurea plants and Glomus irregulare mycorrhizae, was conducted through the Génorem project in a greenhouse. We tested a treatment on soils, which were contaminated with moderate amounts of trace elements (TE) (Cd, Cu, Pb and Zn), as well as with organic compounds (on two levels of concentration). The objectives were 1) to study the effect of the introduced mycorrhizae on TE’s absorption process, as well as the general treatment efficiency; 2) to determine the influence of TE transfer and solubilization processes at work within the rhizosphere on their accumulation rates by the plants, and 3) to measure the impact of soil characteristics as well as the organic contamination on phytoextraction. The presence of inoculate mycorrhizae was not noticeable on the accumulation or transfer of TE, nor was it on the biomass production. However, soluble concentrations of Cu and Pb were less important in the soil rhizosphere of the inoculated soils than in the soil matrix. Plants performance in regard to their accumulation was considerable for Cd (average of 2,80 to 10,1 mg / kg) and Zn (from 54.1 to 410 mg / kg). These elements were mainly accumulated in aboveground tissues, while Cu and Pb were instead stored in the roots. Additionally, most of the soluble concentrations had increased between the beginning and the end of the experiment. This, combined with the differences between the soluble and total-recoverable concentrations in the rhizosphere and the matrix, showed that the soil’s response in terms of time to provide bioavailable TE to plants was not a limiting factor of the system in most cases. Total initial soil concentrations were only correlated to concentrations plant tissues in the case of Cu within stems (R2 : 0,54), and within roots (R2 : 0,58). Fertility and availability factors allowed to explain parts of the variance in concentrations (10% of the total 25% for Cd, and 49% of the total 36% for Cu-aboveground, and 28% of the total 71% for Cu-aboveground), and content (15% of the total 30% for Cd) accumulated. Mixed contamination (organic and inorganic) did not significantly impede the TE extraction, neither the organic compounds degradation.

Förorenade markområden utgör ett stort miljöproblem som orsakar spridning av toxiska metaller till grund- och ytvatten. Samtidigt är många metaller toxiska för djur och människor, vilket gör att markmiljön kan påverkas och risker för människors hälsa uppkommer om de vistas på platsen. I Sverige finns idag över 80 000 förorenade områden och saneringstakten anses inte vara tillräckligt snabb. Metallerna koppar (Cu), bly (Pb) och zink (Zn) hör till de allra vanligasteme tallföroreningarna i jord. Lösligheten av dessa är avgörande för hur biotillgängliga deär samt i hur stor utsträckning de kan spridas till yt- och grundvatten. Biotillgängligheten och halterna i yt- och grundvattnet har i sin tur stor betydelse för hur stor exponeringen blir för människor och djur. Biokol är ett organiskt material som genomgått kemisk omvandling i en syrefattig miljö vid höga temperaturer. Dessa framställningsbetingelser gör att biokol har stora möjligheter att fastlägga metaller genom adsorption till funktionella grupper på dess yta. Samtidigt fungerar biokol som ett jordförbättrande medel. Det anses även kunna lagra kol i upp till 1000 år och därmed fungera som en kolsänka. Biokol kan dessutom tillverkasav organiskt avfall vilket gör att avfallsströmmen minskar när detta framställs. I studien har sex olika biokol blandats in i en jord förorenad med Cu, Pb och Zn. Syftet var att undersöka hur inblandningen påverkade lösligheten av metallerna. Samtidigt testades också fastläggningen av metallerna till tre rena biokol. Det visade sig att lösligheten förändrades när biokolen blandades in i jorden. I pH-intervallet 4 - 6 minskade lösligheten av alla metaller. Det framkom att ett av biokolen var bättre på att fastläggametallerna än de andra. Detta biokol kom från anläggningen i Högdalen, Stockholm och var framställt av trädgårdsavfall. / Contaminated ground constitutes an environmental problem that causes spread of metals to groundwater and surface water. Many of the contaminating metals are toxic to animals and humans and their spreading can cause negative effects on soil environment. In Sweden there are more than 80 000 contaminated sites and the decontamination rate is considered to be too slow. The metals copper, zinc and lead are some of the most common contaminants in soils. The solubility of these metals affects how bioavailable they are and how much they can spread to groundwater and surface water. Bioavailability and concentration in water is crucial for the exposure of metals to humans and animals. Biochar is an organic material that has been chemically transformed in an environment with little or no oxygen, at high temperatures. Due to these conditions, biochar is efficient for reducing the solubility of metals through adsorption to functional groups on its surface. Biochar also improve soil fertility, and it might also remain in the soil up to 1000 years and acts as a carbon sink. Furthermore, biochar can be produced from organic wastes and thus production of biochar can contribute to a reduced waste stream. In this study, six different samples of biochar were mixed with a contaminated soil containing copper, lead and zinc. The aim was to investigate how the adding of biochar would affect the solubility of the metals, since the solubility is crucial for the spread of metals and their bioavailability. The sorption of the metals in three pure samples of biochar was also tested. It was found that the solubility changed when biochar was addedto the soil. In the pH range 4 - 6, the solubility decreased for each metal. One of thebiochar samples had better sorption capacity in the soil than the others. This biochar was produced from garden wastes in Högdalen, Stockholm.

Områden som antas vara förorenade utreds idag med hjälp av Naturvårdsverkets vägledning för förorenade områden. Vägledningsmaterialet baseras till stor del på miljömålet giftfri miljö och vilka risker ett förorenat område kan utgöra för människor och ekosystem. Soil Security-konceptet är relativt nytt och är främst utvecklat för att bedöma jordbruksmarker och bygger på att jordförvaltningen ska leda till att jordresursen bevaras eller förbättras. I detta projekt har en utvärdering utförts om Soil Security-konceptet skulle kunna användas för att arbetet med förorenade områden ska leda mot hållbarhet. Nio indikatorer som alla indikerar att biomassaproduktion fungerar har tagits fram och sedan använts som underlag för jämförelsen mellan Naturvårdsverkets vägledning och Soil Security-konceptet. Dessa indikatorer har även använts för att utreda vad som utförs i det praktiska arbetet med förorenade områden. En analys av hur markmiljön värderas i det praktiska arbetet och om de åtgärder som utförs leder till fungerande markekosystem har också genomförts. Slutligen har Magdalena Gleisner på Naturvårdsverket intervjuats eftersom projektet har en koppling till den utvärdering de utför av vägledningsmaterialet. Vid jämförelse av utgångspunkterna bakom Soil Security-konceptet och Naturvårdsverkets vägledning hittades både skillnader och likheter. I stora drag är Naturvårdsverkets vägledning främst inriktad på vilka risker en förorenad jord kan utgöra och ser inte jorden som ett skyddsobjekt som behöver skyddas eftersom den kan utföra funktioner som är till nytta för människor och ekosystem. I Soil Security- konceptet är utgångspunkten att skydda markfunktioner för att de senare ska kunna bidra till att lösa globala samhällsutmaningar som exempelvis säker tillgång på livsmedel och vatten. När ramverken jämfördes med avseende på indikatorerna för biomassaproduktion fanns de flesta av indikatorerna med i Naturvårdsverkets vägledning, antingen direkt eller indirekt. Hur indikatorerna sedan analyserades för att bedöma jordens tillstånd var den största skillnaden mellan ramverken. I Soil Security- konceptet används indikatorerna för att avgöra om växtetablering kan ske och även jordens status, medan i Naturvårdsverkets vägledning bedöms istället vilka risker föroreningarna kan utgöra. Tre praktiska fall har också utvärderats och i dessa har Naturvårdsverkets vägledning följts till största delen. Markmiljön har bedömts skyddas av åtgärderna i två av tre fall, dock är det enda kravet på återfyllnadsmaterialet att det inte bidrar till ökade föroreningshalter. För att markfunktioner ska fungera och åtgärderna ska leda mot hållbarhet krävs även att markmaterialet exempelvis har en god jordtextur, ett gynnsamt pH-värde och innehåller näring. För att arbetet med förorenade områden ska leda mot hållbarhet behövs en ny vägledning där Soil Security-konceptet beaktas, nya studier tas fram och delar av den gamla vägledningen används. / In this project, today’s work with contaminated sites was evaluated. In Sweden when assessing sites that probably are contaminated, a guideline made by the Swedish EPA is used. This guideline was compared with the soil security concept both by comparing the foundations, and which indicators that differs between the frameworks. The differences in the foundations were that in the Swedish EPA guideline focus is on the risks contaminated sites could have on humans and ecosystems. The soil security concept on the other hand focuses in functioning soil functions to contribute in global societal challenges. In the comparison evaluating the indicators, nine indicators for the soil function production of biomass were formulated. All of the indicators are mentioned in the soil security concept and even in the Swedish EPA guidelines most of them are mentioned either direct or indirect. The biggest differ between the frameworks is how the indicators are analyzed. In the Swedish EPA guidelines, the risks the indicators could provide are analyzed, while in the soil security concept the indicators are analyzed to know if plants can be established in the area. The practical work with contaminated sites was also evaluated in the project. The same indicators where used to see if differences could be found between the actual work and the Swedish EPA guidelines. Three studies were evaluated and they followed most of guidelines. The soil ecosystem was assessed to be protected in two of the three studies, even though the filling material that could be used only has one requirement that it not contributes to increasing contamination levels. This could lead to non-sustainability due to soil material that is incapable of plant establishment and other important soil functions. If the work with contaminated sites should reach sustainability a new framework needs to be produced which has parts from the Swedish EPA guidelines, the soil security concept and even new research.

Miljöriskbedömningar av förorenade områden i Sverige har traditionellt sett främst bedömt saneringsbehovet genom att mäta totalhalter av föroreningarna. Halterna jämförs sedan med riktvärden för att avgöra om de utgör en risk för något av skyddsobjekten. Oftast blir markmiljön det skyddsobjekt som har lägst riktvärde och därmed avgör saneringsbehovet. Kritik har riktats mot att andra faktorer än föroreningshalter borde mätas för att bedöma markkvalitet då den kan vara hög oavsett föroreningssituation. Det är inte heller självklart att en sanering leder till en förbättring av markekosystemet. I Sverige har över 85 000 områden identifierats som potentiellt eller konstaterade förorenade områden. För att förbättra riskbedömningar behövs bättre vägledning om vad som ska ingå i riskbedömningar och för det behövs kunskap om vad som påverkar markfunktionerna.I det här examenarbetet har nitrifikationspotentialen, också kallat ammoniakoxidation, bestämts för 50 jordprover från fastigheten Skönsmon 2:12 i Sundsvalls kommun med hjälp av ISO metoden 15685. Tidigare industriverksamheter på fastigheten har lett till att marken är förorenad med bland annat tungmetaller och polycykliska aromatiska kolväten. Markens förmåga att utföra nitrifikation är en viktig markfunktion för att säkerställa en god markkvalitet. Men vilka markfaktorer som i störst utsträckning påverkar ammoniakoxidationen är inte helt klarlagt, liksom hur olika typer av miljöföroreningar påverkar nitrifikationen. Detta behöver klargöras för att kunna bedöma om ISO-metoden 15685 är ett lämpligt verktyg för markekologiska riskbedömningar av förorenade områden. Nitrifikationsanalysen på de 50 jordproverna har därför jämförts med data över föroreningshalter, markparametrar samt mängden ammoniakoxiderande bakterier och arkéer. Resultatet visar att nitrifikationen på den här lokalen främst påverkas av markparametrarna: totalkväve, organiskt material samt ”tillgänglig” fosfor och i mindre utsträckning av föroreningsnivåerna. Detta betyder att det vid undersökningar av hur föroreningar påverkar nitrifikationen måste finnas referensprover med liknande markkvalitet att jämföra med. Den potentiella nitrifikationen visar också stark korrelation till populationen ammoniakoxiderande bakterier vilket indikerar att de står för det största bidraget till ammoniakoxidationen i marken. / Environmental risk assessment of contaminated sites in Sweden has traditionally mainly assessed the need of remediation by measuring the total concentrations of pollutants. The pollution levels are then compared with guideline values to determine if they represent a risk to any of the protected targets. Most often, the soil environment is the protection target with the lowest guideline value and thus determines the need for remediation.There has been some criticism about using total concentration of pollutants as the only method of assessing soil quality, since soil quality may be high regardless of the situation of the polluted area. In addition, it is not clear if the remediation will always lead to an improvement of the soil quality. In Sweden, more than 85,000 sites have been identified as potential or confirmed contaminated areas. In order to improve risk assessments, better guidance is needed regarding what information should be included. This requires knowledge of which factors are affecting the soil functions.In this thesis, potential nitrification has been determined for 50 soil samples from the property Skönsmon 2:12 in the municipality of Sundsvall using ISO standard 15685. Previous industrial activities on the property have resulted in the soil being contaminated with, for instance, heavy metals and polycyclic aromatic hydrocarbons. The ability of the soil to perform nitrification is an important soil function to ensure good soil quality. However, it is not entirely clear which soil factors affect nitrification to the greatest extent, nor how different types of environmental pollution affect nitrification. This needs to be clarified in order to assess whether ISO 15685 is an appropriate tool for soil ecological risk assessments of contaminated sites. The nitrification data of the 50 soil samples have therefore been compared with data of pollutants, soil parameters, and the amount of ammonia oxidizing bacteria and archaea. This study showed that ammonia oxidation at this site is mainly affected by the soil parameters total nitrogen, organic matter, and “available” phosphorus content, but to a lesser extent of the pollutant levels. This means that when examining how pollutants affect nitrification, reference samples with similar soil quality must be included for comparison. The potential nitrification showed a strong correlation with the population of ammonia oxidizing bacteria, which indicates that they account for the biggest contribution to ammonia oxidation in the soil.

Abstract Industrial emissions and soil pollution caused by harmful substances attracted an increased public awareness in the 1970s. Ministry of the Environment contributed to the rapid development of environmental legislation. Development of Finnish environmental legislation has also been significantly affected by the membership of the EU has been in 1995. Finnish legislation is largely based on EU legislation, but in some cases it includes even stricter standards and limits than those applied on the EU level. Studies of contaminated soils in Finland began with mapping of landfills in the 1980s. The clearing and renovation project of contaminated soils named SAMASE started in 1988, and approximately 10,400 contaminated areas were surveyed. Currently, the total number of objects has already expanded to about 25,000. This thesis consists of five scientific publications related to contaminated sites. Its summary deals with environmental legislation, treatment methods for soils contaminated with oils and heavy metals, and risk assessment in general. The scientific publications focus on the utilization of two chemical methods, i.e. oil biodegradation of contaminated soil studied, especially by manometric respirometric BOD Oxitop method, and the study of railway ballast using five-step sequential extraction method. The results show that the biodegradability of oil is strongly dependent on the soil matrix and the studied oils (motor and light fuel oils), which are biodegradable well under suitable conditions. When a 6-month long biodegradation study of light fuel contamination in mineral-rich soil without soil conditioning was performed, the final biodegradation degree was surprisingly almost complete (> 90 %), in contrary to the general assumption. Thus, the inherent biodegradability is a cost-efficient and a recommended treatment method for oil contaminated soils, especially in sparsely populated areas. Research of the railway ballast showed that the multi-step sequential extraction will provide valuable information about the effects of environmental circumstances on metals bioavailability or solubility for the purposes of risk assessment. This information is necessary to understand the actual environmental risks of metals in different natural environments, thus contributing to the development of licensing procedure. The results of this thesis also show that licensing related to the restoration of contaminated soils r (authority and control procedures) must be simplified. The authorities should also have sufficient chemical knowledge, since after all, environmental problems are mainly of chemical nature. / Tiivistelmä Huoli ympäristöstä nosti 1970-luvun alussa erilaiset päästöt päivänvaloon, ja haitallisten aineiden aiheuttama maaperän pilaantuminen nousi esille 1980-luvulla. Suomeen vuonna 1983 perustettu ympäristöministeriö on edesauttanut nopeaa ympäristölainsäädännön kehittymistä. Kehitykseen on vaikuttanut merkittävästi myös EU-jäsenyytemme vuodesta 1995 lähtien ja jäsenyyden myötä implementoitu EY:n lainsäädäntö. Joiltain osin säädöksemme ovat jopa tiukempia kuin EU:n vastaavat säännökset. Suomessa pilaantuneiden maiden selvitystyö alkoi kaatopaikkojen kartoituksella 1980-luvulla. Valtioneuvoston v. 1988 antaman selonteon pohjalta käynnistyi saastuneiden maa-alueiden selvitys- ja kunnostusprojekti (SAMASE), jossa kartoitettiin noin 10 400 pilaantuneeksi epäiltyä tai todettua aluetta. Tätä työtä jatketaan edelleen viranomaisten tavanomaisen lupa- ja valvontatyön ohessa. Tällä hetkellä kohteiden kokonaismäärä on noin 25 000. Tämä pilaantuneisiin maihin (PIMA) liittyvä väitöskirjatutkimus koostuu yhteenveto-osasta, jossa käsitellään alan lainsäädäntöä, käsittelymenetelmiä ja riskinarviointia yleisesti sekä viidestä osajulkaisusta, jotka keskittyvät öljyllä pilaantuneiden maiden biohajoavuuteen manometrista respirometrista BOD Oxitop -menetelmää käyttäen ja kaivosteollisuuden sivukiven (raidesepeli) raskasmetallien analytiikkaan sekventiaalista uuttoa hyödyntäen. Tutkimuksen tulokset osoittavat, että öljy biohajoaa maassa sopivissa olosuhteissa hyvin ja luontainen biohajoavuus on täten yksi käyttökelpoinen öljyllä pilaantuneiden maiden puhdistusmenetelmä. Raidesepelitutkimukset osoittivat, että monivaiheinen sekventiaalinen uutto tuo uutta arvokasta tietoa olosuhteiden vaikutuksista metallien biosaatavuudesta/liukoisuudesta niiden riskinarviointia varten. Tämä tieto on välttämätöntä, kun halutaan ymmärtää metallien todelliset ympäristövaikutukset erilaisissa luonnonolosuhteissa ja näin edistää osaltaan lupamenettelyn kehittämistä. Väitöskirjassa todetaan myös, että pilaantuneen maan kunnostuksiin liittyen viranomaisten lupa- ja valvontamenettelyä tulee yksinkertaistaa ja viranomaisilla tulisi olla riittävästi kemian tietämystä ja kemiallista ajattelua, ovathan ympäristöongelmat pääosin luonteeltaan kemiallisia.

Arsenik är en naturligt förekommande halvmetall som orsakar stora hälsoproblem genom exponering t.ex. via dricksvatten. På grund av arseniks negativa effekter på människors hälsa sänktes den tillåtna gränsen i dricksvatten från 50 μg/l till 10 μg/l 2003 av WHO. Arsenik förekommer i huvudsak i två oorganiska former, arsenat (AsO43-) och arsenit (AsO33-), där arsenit är en betydligt mer mobil och toxisk form. Vilken form som dominerar påverkas i första hand av redoxförhållanden men även av pH. Reduktion från arsenat till arsenit är gynnsamma vid lägre pH och vid syrefria (reducerade) förhållanden. I Sverige har tidigare användning av arsenik, t.ex. vid impregneringsanläggningar, orsakat föroreningar som än idag ligger kvar. I Hjältevad i Eksjö kommun drev Televerket under 1940- till 1980-talet en impregneringsanläggning för telefonstolpar. Impregneringsvätska, innehållande bland annat arsenik, kunde spridas inom området till största del på grund av en tank som började läcka under 1960-talet. En omfattande sanering med jordtvätt genomfördes 1997. Senare kontroller har dock påvisat stadigt ökade halter. Med anledning av de ökade halterna har ett arbete inletts för att kartlägga föroreningssituationen. Syftet med examensarbetet är att utvärdera grundvattenkemin i Hjältevad genom att visualisera föroreningsföroreningsplymen, undersöka mobiliteten genom att undersöka samband mellan halten arsenik och kemiska parametrar samt göra en fördjupad analys av spridningsrisken med hjälp av Kd-värden. Data från jord- och grundvattenprovtagningar genomförda under augusti och september 2017 bearbetades med hjälp av ArcMap och Excel. Resultatet visade att låga redoxförhållanden sannolikt har bidragit till ökad spridning av arsenik vilket till stor del förekom i den reducerade formen arsenit. De högsta halterna var koncentrerade till området kring den f.d. läckande tanken, där halter så höga som 2200 μg/l kunde uppmätas i grundvattnet. Vidare visade provtagningsresultaten att mängden förorenad jord missbedömdes vid saneringen 1997 (halter på 238 mg/kg kunde uppmätas i jorden). Slutsatsen drogs att redoxförhållanden inom området är gynnsamma för att arsenik ska förekomma i den reducerade formen arsenit, att arseniks mobilitet med stor sannolikhet är betydligt högre än vad som tidigare bedömdes samt att risker föreligger om inga åtgärder vidtas. / Arsenic is a naturally occurring metalloid that causes major health problems for people affected by exposure, e.g. through their drinking water. Due to the negative effects on human health, the permissible concentration in drinking water was lowered in 2003, from 50 μg/l to 10 μg/l. Arsenic predominantly exists in two inorganic forms, arsenate (AsO43-) and arsenite (AsO33-), where arsenite is a more mobile and toxic. Which forms that dominates is controlled by pH and redox potential. Reduction from arsenate to arsenite is favorable at lower pH and at anoxic (reduced) conditions. In Sweden previous use of arsenic, e.g. at impregnation plants, caused pollution still affecting soils and groundwater. In Hjältevad, Eksjö municipality, an impregnation plant for telephone poles was run by Televerket during the 1940s to 1980s. Impregnating fluid, including arsenic, was spread in the area, mainly due a leaky storage tank during the 1960s. The site was remediated in 1997 using soil washing. However, monitoring program demonstrated steadily increased levels in a well situated downstream the contaminated area. Due to the increased contamination levels of arsenic in the ground water, a detailed investigation was initiated to identify the pollution situation. The main objective was to investigate about the chemical and physical processes affecting the mobilization of arsenic. Groundwater and soil materials were sampled from the area and evaluated using ArcMap and Excel. In support of this evaluation, distribution coefficients (Kd) for soil materials from the aqvifer were obtained by leaching tests performed at oxidized conditions. The result showed that reducing conditions in the aquifer appeared to have caused increased mobilization of arsenic in the area and that large amounts of pollution was not removed at the remediation in 1997 (levels of 238 mg/kg arsenic could be detected in the soil). In the collected samples, arsenic mainly occurred in the reduced form arsenite. The highest levels in the groundwater were found in the area around the former leaky tank, where concentrations up to 2200 μg/l was measured. The conclusion was that large amounts of pollution was not removed at the remediation in 1997, and that arsenic mobility seems to be significantly higher than previously assessed and that action needs to be taken to stop the spread.

In Canada, about 60% of contaminated sites involve petroleum hydrocarbon (PHC) contamination and most of these sites have been abandoned due to contamination. Among current technologies used for soil remediation, supercritical fluid extraction (SFE) is a relatively recent and potentially viable method. The main aim of this research was to investigate the application of SFE for removal of PHCs from contaminated soils. In the first phase, the effects of SFE operational parameters including fluid pressure, fluid temperature, time duration and mode of extraction on the removal efficiency of PHCs from a spiked sandy soil (with diesel fuel with a ratio of 5 wt%) were investigated. SFE experiments were performed at different pressures (15, 33 and 50 MPa) and temperatures (30, 75 and 120 °C). The combination of 10 min static mode followed by 10 min dynamic mode, repeated for 3 cycles (60 min in total) led to the highest PHC removal percentage. According to response surface methodology (RSM), the optimum pressure and temperature were found to be 50 MPa and 69.3 °C, respectively. According to experimental results, the optimum combination of pressure and temperature determined to be 33 MPa and 75 °C; which resulted in the extraction percentages of 99.2%, 91.7% and 86.1% for PHC F2, F3 and F4 fractions, respectively. In the second phase, the influence of several parameters including soil water content, soil pH and addition of modifier on PHCs removals from a field-contaminated sandy soil using SFE were experimentally investigated. SFE experiments were performed at 33 MPa pressure and temperatures of 45 and 75 °C. Three water content levels of 8%, 14% and 20% at two levels of pH 6.5 and 7.5 were investigated. The extraction of total petroleum hydrocarbon fractions (TPHF), the sum of F2, F3, and F4 fractions, decreased due to the increase in the water content from 8% to 20% at both pH 6.5 and 7.5. The difference of extractions of all PHC fractions at pH values of 6.5 and 7.5 were not statistically significant (at p < 0.05 confidence level) at all three water content levels and pH did not have a significant influence on the PHC removal efficiency. Addition of acetone as a modifier (33.7% TPHF removal) was more effective than hexanes (24.3% TPHF removal) to decrease the concentrations of PHCs for the field contaminated soil. In the third phase, the influence of soil texture and grain size on the extraction of PHC fractions was investigated. SFE experiments were performed at 33 MPa pressure and 75 °C temperature. Three types of soils (soil A, B and C) were spiked with diesel fuel with a ratio of 5 wt%. Soil A, B and C had different particle sizes and were categorized as sand, silt loam and clay, respectively. Soil A (sand) which had the largest particle size resulted in the highest TPHF removal percentage while soil C (clay) with the smallest particle size led to the lowest TPHF removal percentage. A higher clay content in soil C resulted in a lower extraction of PHCs. In the fourth phase, the effects of pressure and temperature on the extraction of PHC fractions from a clay soil spiked with diesel fuel with a ratio of 5 wt% were investigated. SFE experiments were performed at three pressures (15, 33 and 50 MPa) and temperatures (30, 75 and 120 °C). According to the statistical analysis including factorial design and RSM, the optimized combination of pressure and temperature was selected at 42.8 MPa and 120 °C; which resulted in the removal percentages of 74.9% and 65.6% for PHC F2 and F3 fractions, respectively. The optimum combination of pressure and temperature based on the experimental results was selected at 33 MPa and 120 °C that led to 70.3%, 58.4% and 32.6% removal of PHC F2, F3 and F4 fractions, respectively.

The enormous rate of increase in waste generation across the world is a serious threat to the future generation, if not handled properly, due to the creation of health hazards and global warming. This was awakened many engineers and researchers to find an appropriate solution for efficient management of waste. The land filling of the waste is the most widely adopted method for its disposal, whose efficiency mainly depends on the engineered barrier system in place. Though possessing many limitations, clay liner solely or along with Geo-membrane is often used to avoid ground and surface water contamination. The thickness of the liner of a given breakthrough time depends on the transport rates of the selected contaminants. To estimate the transport rate of any given contaminant, it is necessary to understand the different migration processes of contaminants through the liner material. It was observed from the literature that, the transport rate of contaminants mainly depends on Dispersion coefficient (D) and Distribution coefficient (K) which are the main contaminant transport parameters. The amount of contaminant transport through the liner system for a desired time period is thus estimated from these contaminant transport parameters using the Advection-Dispersion Equation (ADE). The unregulated open dumps are another cause of serious environmental problem, where the contaminants are free to migrate in any direction through the underground soil. The percolation rate and the accumulation of leachate increase during the rainy season, which picks up more contaminants from the waste and thus the threat of the leachate increases. The leachate normally migrates in vertical and lateral directions, causing contamination of ground and surface water resources, and hence, there is a need to estimate the transport rates of contaminants in the porous media. These transport rates are not only useful for designing barrier systems, but also useful to find a suitable remediation technique for the removal of contaminants from a contaminated site. Thus, determination of transport rate is very important in effective waste management systems. Most of the researchers have obtained the contaminant transport parameters through the column tests to simulate one dimensional flow. Often, it is a lengthy process and there is a need to find an easy and effective method of determining these parameters which can reduce the time and effort. Generally, the metallic contaminants such as Cadmium (Cd), Copper (Cu), Lead (Pb), Mercury (Hg), Nickel (Ni) and Zinc (Zn) which are most hazardous are considered for the contaminant migration studies. In the present study, the transport rates of two heavy metals Copper and Zinc through locally available Black Cotton soil and Red soil were studied. Column experiments were conducted to simulate the field conditions under two types of test conditions i.e., Constant and Decreasing source concentrations. For Black Cotton soil as the hydraulic conductivity was very less and was taking a long time for achieving complete breakthrough, the soil sectioning method was used to get the depth versus concentration. The soil sectioning method involves the determination of pore water concentration of any given contaminant in different sections of the soil column. The depth versus concentration profile can serve as the same purpose as that of complete column test after breakthrough. The column experiments can be done only up to a relative concentration (C/C0) of about 0.2 instead of 0.8 or more. The soil samples were compacted to different densities to know the effect of density on transport parameters. The Black Cotton Soil samples were compacted to 0.76-0.97 times of maximum dry density and Red Soil samples were compacted to 0.81-0.98 times of maximum dry density. The samples were compacted to lesser densities to reduce the experimentation time. The transport parameters for field densities can be determined by setting „Forecast Trend Lines‟ to the density versus dispersion coefficient and density versus distribution coefficient plots. The contaminant transport was modeled by various methods i.e., Analytical, Semi-analytical, Explicit Finite Difference and Implicit Finite Difference methods. These models can be extended to predict the contaminant migration through soil liners constructed with similar soils. During the lifetime of a landfill, it may be subjected to both constant and decreasing source concentration conditions and thus the contaminant transport parameters determined by both constant and decreasing tests will be useful to estimate the optimum thickness of soil liner. The disposal of waste solutions and sludges by industries has led to problems with the contamination of both soil and groundwater. Much research work has not been carried out in the past for the remediation of contaminated soils in India. Thus an attempt has been made to study in detail the different remediation techniques on various contaminated soils. Three heavy metal contaminated soils were studied with two remediation techniques i.e., Soil washing and immobilization. As a case study, Zinc contaminated soil was collected from Hindustan Zinc Limited located near Udaipur in Rajasthan State, India and column leach tests were conducted on this soil with different leaching solutions to study the efficiency of the soil washing technique. The leaching solutions used for removing zinc from this soil were 0.1N HCl, 0.1N EDTA, 0.1N HCl+0.1N EDTA and 0.1N FeCl3. It was found that 0.1N FeCl3 was more efficient to remove zinc from this soil. The removal efficiency was also high with 0.1N HCl+0.1N EDTA solution. The transport rates were determined by matching the theoretical elution curves with experimental elution curves. The contaminant transport for column leach tests was modeled using analytical solution based on the Leaching Mass Ratio approach. These transport rates are useful to estimate the rate of treatment as well as the amount of flushing solution required to remove Zinc knowing the area of contamination and in-situ soil conditions. One of the potential sources of soil and ground water contamination with toxic metal ions is Effluent Treatment Plant sludge (ETP Sludge). The efficiency of soil washing technique was also studied on ETP Sludge using five leaching solutions i.e., distilled water, 0.1N HCl, 0.1N EDTA, 0.1N HCl+0.1N EDTA and 0.1N FeCl3. ETP sludge was collected at a filter press, KIADB industrial area, Doddaballapur, Bangalore. The removal efficiencies of these leaching solutions for removal of different metal ions (Copper, Zinc, Iron, Nickel, Cadmium, Lead and Chromium) were studied. The highest removal efficiencies were observed with 0.1N FeCl3 and 0.1N HCl+0.1N EDTA. The transport rates of different metals were determined which will be useful to estimate the quantity of leaching solution required in the field to remediate this sludge using soil washing technique. Even though soil washing technique is more effective than immobilization, for less permeable soil with more clay content, it is not a cost effective method. In such cases immobilization technique can be used to remediate the contaminated soil. The immobilized metals will not migrate through soil to groundwater and will not give adverse environmental hazards in their treated state. In the present study, immobilization technique was studied on two materials, (i) contaminated soil from open dump and (ii) ETP Sludge. The contaminated soil was collected from an open dump located at the Bingipura dumping yard, Bangalore and was tested for the presence of heavy metal ions. The efficiency of treatment to immobilize the metals was studied with different additives. The chemical agents with which can decrease the solubility product will be effective to immobilize the metal ions. The stabilizing agents used for treating these materials were lime water, NaOH and cement. These stabilizing agents were selected after preliminary batch tests. Since most of the heavy metals in soils become less mobile with increase in pH, the lime water / NaOH was added to the soil/sludge to adjust the pH of the mixture to 7.0, 8.5 and 10.0. The cement: soil ratios used were, 1:100 (pH=6. 8), 1:50 (pH=8. 1) and 1:25 (pH=9. 8) by weight. Leaching tests were conducted on the amended soils to know the long term efficiencies of the chemical agents for immobilizing the metal ions. The work carried out in this thesis is presented in different chapters as given below: For the design of the liner system, it is necessary to know the different contaminant transport processes, the determination of their rates and modeling. For remediation of contaminated soil, it is required to find the suitable remediation technique based on the amount and type of pollutants, the type of soil and other geological conditions. The detailed information about sources of heavy metals, effects of heavy metal contamination on health and the environment, contaminant transport processes, methods of determining transport rates, and different modeling techniques for contaminant transport are explained in Chapter 1. The Background information along with the scope and objectives of this study are presented in this chapter. The extensive review of literature related to column experiments, various solutions to Advection-Dispersion Equation, and different remediation techniques to treat the contaminated soil, is also presented in this chapter. Chapter 2 gives detailed information about various materials and methods used in this study. The characteristics of soils used in the present study and preparation of different chemical solutions were explained. The experimental procedures of batch tests, column tests and soil sectioning to determine the contaminant transport parameters were given in detail. The experimental procedures that are required for assessing the efficiency of soil washing technique i.e., Batch leach tests and column leach tests were also explained. The laboratory assessment of immobilization efficiency through leaching test was explained briefly. The analytical and numerical solutions used for this study were discussed in detail. This chapter also includes a method of prediction of breakthrough curves from the incomplete column test data. The contaminant transport parameters of metal ion Copper in two locally available soils i.e., Black cotton soil and Red soil were determined by various techniques i.e., Analytical (using MATLAB v7 software), semi-analytical (using POLLUTE v7 software), Explicit Finite Difference Method with two software tools (MATLAB v7 and M.S.EXCEL 2010), Implicit Finite Difference method with three schemes (BTCS, UPWIND & CRANK NICOLSON) using two software tools (MATLAB v7 and M.S.EXCEL 2010). Modifications were done in the spreadsheet solution of non-reactive solute available from the literature to incorporate the retardation factor as the solutes used in this study are reactive in nature. These results are presented in Chapter 3. The contaminant transport parameters determined for different test conditions (constant and variable source concentrations) and for different densities of soil are reported in this chapter. Determination of transport rates corresponding to maximum dry density using trend lines and preparation of design charts to estimate the thickness of the liner are also discussed in this chapter. The contaminant transport parameters were also determined for metal ion Zinc in the same soils with the same techniques as that of Copper and the migration rates were compared for both the ions. These models and comparative results are presented Chapter 4. It was observed that with increase in density, the dispersion coefficient decreases and Distribution coefficient increases. It was also found that the dispersion coefficient of Black Cotton Soil was lower than that of Red Soil whereas the distribution coefficient of Black Cotton soil is much higher than that of Red Soil. Further, it was observed that the dispersion coefficient of Copper was less than that of Zinc whereas the distribution coefficient of Copper was higher than Zinc. The design of liner thickness, based on transport rates of Zinc is briefly discussed in this chapter. A case study has been explained for the remediation of Zinc contaminated sandy soil using soil washing technique. The undisturbed soil samples collected from four locations of waste disposal site of Hindustan Zinc Limited located near Udaipur in Rajasthan State of Western India were assessed to find the suitable leaching solution and number of pore volumes for the effective removal of Zinc from this soil. The chelates/ solvents used for this soil were 0.1N HCl, 0.1N EDTA, 0.1N HCl+0.1N EDTA and 0.1N FeCl3. The contaminant transport parameters were also determined from the column leach tests based on the Leaching Mass Ratio approach and the results are presented in Chapter 5. From the experimental study it was observed that 0.1N FeCl3 and 0.1N HCl+0.1N EDTA are the most suitable leaching solutions to treat this soil. The Chapter 6 contains the sludge analysis of an industrial ETP sludge, column leach test results of this sludge with different leaching solutions, removal efficiencies of different solutions used and the transport rates of different contaminants. The leaching solutions used for this sludge were distilled water, 0.1N HCl, 0.1N EDTA, 0.1N HCl+0.1N EDTA and 0.1N FeCl3. It was observed that 0.1N FeCl3 and 0.1N HCl+0.1N EDTA are the most suitable leaching solutions to treat this sludge. Other solutions have also removed the contaminants by more than 50%, but the number of pore volumes required to leach out the contaminants was high. The order of removal efficiencies of different solutions is presented below: 0.1N FeCl3 > 0.1N HCl + 0.1N EDTA > 0.1N EDTA > 0.1N HCl > distilled water. The transport rates of different contaminants (Cu, Zn, Cd, Fe, Ni, Pb and Cr) were determined using analytical solution and are presented in this chapter. These transport rates are useful to estimate the quantity of leaching solution required in the field to remediate the sludge using soil washing technique. A contaminated soil collected from an open dump site within Bangalore city and ETP Sludge were analyzed to know the efficiency of immobilization/ solidification technique of remediation using three chemical agents lime, NaOH and cement. The soil samples were mixed with different proportions of these chemicals to adjust the pH of the mixtures to 7.0, 8.5 and 10.0. Leaching tests were conducted on the modified soils to know the long term efficiency of these chemical agents to immobilize the contaminants and these results are discussed in Chapter7. The results showed that highest immobilization efficiencies can be achieved with lime for this contaminated soil and cement is the most suitable chemical agent to treat this sludge. The immobilization efficiencies of different stabilizing agents for various metals were studied and the results analyzed. The Chapter 8 includes the major observations and conclusions of the present research work which will be useful for Geotechnical and Geo-environmental engineers to estimate the transport rates of contaminants, to design the soil liners, to assess the efficiency of soil washing technique to remediate the contaminated soil, to estimate the quantity of leaching solution required in the field for soil washing and to find the suitable chemical agent for remediating the contaminated soil by immobilization technique.

I Sverige finns det ungefär 25 000 riskklassade förorenade områden samt ännu fler områden som potentiellt är förorenade. Naturvårdsverket har tagit fram generella riktvärden för olika förorenade ämnen. Halter över riktvärdena antyder att risken för negativa effekter på människan eller miljön bedöms vara stor och att efterbehandling av området är aktuellt. Ett vanligt, men kostsamt efterbehandlingsalternativ är urschaktning och bortforsling av jord innehållandes halter av ämnen över riktvärdena. Ett intresse finns för att utveckla lätt tillämpbara metoder för platsspecifik riskbedömning av mark i syfte att skydda markmiljön och dess funktioner. Mikroorganismer som ingår i kvävets kretslopp utför nyckelfunktioner i jorden. Flera studier indikerar att dessa mikroorganismers abundans och aktivitet påverkas av flera olika markföroreningar. Inom forskningsprojektet APPLICERA har ett lysimeterexperiment genomförts där två jordar, med olika egenskaper med avseende på bland annat kornstorleksfördelning och pH (svagt basisk sandy loam respektive sur sand), förorenats med koppar respektive PAH:er i varierande halter. Halterna motsvarar riktvärden för känslig markanvändning (KM), mindre känslig markanvändning (MKM) och 3xMKM. Provtagning av jorden har skett vid tre tillfällen under en period av 16 månader. I detta examensarbete har nitrifierande mikroorganismers potential för att användas som indikatorer för förändrad markfunktion i förorenad jord undersökts. Detta har gjorts genom att kvantifiera ammoniakoxiderande arkéer (AOA), ammoniakoxiderande bakterier (AOB) samt de nitritoxiderande bakteriesläktena Nitrospira och Nitrobacter i jord som provtagits vid de olika tidpunkterna i lysimeterexperimentet. Mätning av potentiell ammoniakoxidation (PAO) har skett för jord från det sista provtagningstillfället. Resultaten visade att abundansen av mikroorganismerna generellt var större i den svagt basiska jorden klassificerad som sandy loam än i den sura jorden klassificerad som sand. Med tiden minskade AOA:s abundans för den högsta koncentrationen av koppar och PAH, särskilt utpräglad var minskningen i den sura jorden. Även Nitrospira minskade i abundans i PAH-förorenad jord för båda jordtyperna, dock kunde en minskning i abundans i kopparförorenad jord statistisk endast säkerställas för den sura jorden. AOB:s och Nitrobacters abundans visade inte på någon tydlig uppåt- eller nedåtgående trend varken över tid eller för ökande föroreningshalt. Skillnaden i kvantitet av mikroorganismer mellan jordtyperna antyder att jordens kemiska och fysiska egenskaper påverkade mikroorganismernas abundans såväl som föroreningarnas biotillgänglighet. PAO minskade med ökande kopparhalt för båda jordtyper, däremot sågs en minskning i PAO med ökande PAH-halt endast i den sura jorden. Resultaten antyder att abundansen av AOA och Nitrospiras verkar ha störst potential att utgöra generella indikatorer över ändrad markfunktion, dock lämpligen med komplettering av förbättrade mätningar av PAO för att få mer information om kvävets kretslopp i förorenad jord. / In Sweden there are around 25,000 contaminated areas classified as a risk for human health or the environment, and even more potentially contaminated areas. The Swedish Environmental Protection Agency has developed generic guideline values for hazardous substances.  Contamination levels exceeding the guideline values indicate a large risk for human health or the environment and that there is a need to remediate the site. A frequently used and expensive aftertreatment is excavation and removal of contaminated soil. Therefore, there is an interest to develop easy applicable methods for site-specific risk assessment with the purpose to protect the soil environment and its functions. Microorganisms involved in the nitrogen cycle perform key functions in soil. Several studies indicate that the abundance and activity of N-cycling microorganisms are sensitive to various soil pollution. Within the research project APPLICERA, a lysimeter experiment was conducted with two different soil types (acidic sandy soil and slightly alkaline sandy loam) and different contamination levels of copper and PAH. The contamination levels corresponded to generic guideline values for sensitive land-use (KM), less sensitive land-use (MKM) and 3xMKM. Soil samples were taken at three times during a period of 16 months. The aim of this master thesis was to investigate nitrifying microorganism potential as indicators for altered soil functioning in contaminated soil. Ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB) and the nitrite-oxidizing bacteria genera Nitrospira and Nitrobacter has been quantified in soil samples with the different treatments. Measurements of the potential ammonia oxidation (PAO) have been performed in soil from the last sample taking.  The abundance of the nitrifying microorganisms was in general higher in the slightly alkaline sandy loam soil. Over time there was a decrease in AOA abundance for the highest concentration of copper and PAH, most pronounced in the acidic sandy soil. Also, a decrease in the abundance of Nitrospira in soil contaminated with PAHs could be seen for both soil types. In copper contaminated soil a distinct decrease in the abundance of Nitrospira could only be seen in the acidic sandy soil. The abundance of AOB and Nitrobacter did not show any obvious pattern for different contamination levels or over time. The difference in abundance of nitrifying microorganisms between the soil types suggests that the soil’s chemical and physical characteristics as well as the bioavailability of the contaminant affected their abundance. A significant decrease in PAO could be seen for the highest contamination level of copper for both soil types, but for the PAH contaminated soil PAO decreased only in the acidic sandy soil. These results suggest that the abundance of AOA and Nitrospira seems to have greatest potential as general indicators for altered soil functioning. However, improved activity measurements are needed to gain greater insight into the soil N-cycle functioning in contaminated soils.

Neun Fachbeiträge dokumentieren die Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes in den Themenbereichen Grundwasser, Altlasten und Boden.