A Mata Atlântica é reconhecida como área de prioridade de conservação na América do Sul, devido ao grande número de espécies endêmicas e constantes ameças à sua biodiversidade em decorrência da substituição da vegetação natural. Embora várias informações sobre a diversidade vegetal e animal estejam disponíveis, pouco se sabe sobre a diversidade de microorganismos existentes no solo desse bioma. A diversidade de fungos do solo foi avaliada em três unidades de conservação da Mata Atlântica do estado de São Paulo: Parque Estadual de Carlos Botelho (PECB), Estação Ecológica de Assis (EEA) e Parque Estadual da Ilha do Cardoso (PEIC). Ao todo, foram analisadas 90 amostras de solo, coletadas em épocas de alta e baixa pluviosidade, e sob a copa de três espécies arbóreas: Cabralea canjerana, Guapira opposita e Maytenus robusta. Foram utilizados métodos independentes (PCR-DGGE e pirosequenciamento) e um método dependente do cultivo (lavagem de solo e filtração de partículas) para a análise da diversidade e estrutura das comunidades de fungos do solo. Os resultados obtidos foram analisados conjuntamente com os dados de atributos químicos do solo e frações da matéria orgânica do solo a fim de verificar suas possíveis relações com as comunidades de fungos. Os resultados obtidos sugerem uma grande diversidade de fungos no solo da Mata Atlântica. Através do método de cultivo, um total de 142 espécies de fungos foi identificado nas três áreas, sendo que a estrutura das comunidades de fungos não foi influenciada pelas espécies arbóreas, mas sim pelas áreas e épocas de amostragem. As comunidades de fungos cultiváveis do PECB e do PEIC foram mais similares entre si do que em relação às comunidades de fungos do solo da EEA, assim como os valores dos atributos químicos do solo dessas áreas foram mais semelhantes entre si. Pelo método de PCR-DGGE, as estruturas das comunidades de fungos das três áreas sofreram influência das espécies arbóreas sob a copas das quais as amostras foram coletadas. Somente a estrutura das comunidades de fungos no solo do PEIC não sofreu influência da época de amostragem. Usando pirosequenciamento, foram obtidas 39.152 sequências da região ITS de fungos, as quais foram agrupadas em 1.800 Unidades Taxonômicas Operacionais (UTOs). A diversidade de fungos na EEA e no PEIC variou em função das espécies arbóreas e épocas de coleta. A análise de NMS de cada área amostrada indicou que as comunidades de fungos do solo são muito homogêneas. O filo Ascomycota foi mais frequentemente detectado, tanto usando metodologia dependente quanto independente de cultivo. De maneira geral, as comunidades de fungos cultiváveis apresentaram maior relação com atributos químicos do solo, áreas e épocas de coleta, e as comunidades de fungos acessadas por PCRDGGE mostraram maior relação com as épocas de coleta e espécies arbóreas sob as quais as amostras de solo foram coletadas. A análise dos metadados usando rede neural revelou uma dependência da diversidade de fungos em relação às concentrações de ácidos húmicos, ácidos fúlvicos e humina no solo, além do pH e concentração de matéria orgânica total. / Brazilian Atlantic Forest is recognized as a top priority for conservation in South America because of its large number of innate species and the threats for the biodiversity due to vegetation changes. Although a plethora of data on plant and animal diversity in the Atlantic Forest is available, the diversity of soil microorganisms in this biome is still mostly unknown. Therefore, soil fungi diversity was evaluated in three Atlantic Forest conservation areas of São Paulo state: Estação Ecológica de Assis (EEA), Parque Estadual de Carlos Botelho (PECB) and Parque Estadual da Ilha do Cardoso (PEIC). A total of 90 soil samples were analyzed, collected in two different seasons (high and low precipitation seasons), and under the canopy projection of three tree species: Cabralea canjerana, Guapira opposita and Maytenus robusta. Two independent cultivation methods (PCR-DGGE and pyrosequencing) and one dependent method (soil washing and particles filtration method) were used for the analysis of soil fungi diversity and community structure. The results of these methods were analyzed together with the data on soil chemical attributes and organic matter fractions in the same samples, in order to verify the possible relations with soil fungi communities. The results suggest a great diversity of soil fungi in the Atlantic Forest. Through the cultivation method, a total of 142 fungi species were identified for the three areas. The structure of fungi communities was not affected by the tree species, but were affected by the sampling areas and seasons. Cultivable fungi community in PECB and PEIC were more similar to each other than in EEAs soil fungi community. In addition, the values of the chemical properties of these areas were more similar to each other. The structure of soil fungi community accessed by PCR-DGGE showed that the three areas were influenced by the tree species under the canopy where the soil samples were collected. Only the structure of PEICs fungi communities was not influenced by the season. By means of pyrosequencing, 39,152 sequences were retained from the ITS rDNA region, which were clustered in 1,800 Operational Taxonomic Unities (OTUs). Fungal diversity in EEA and PECB areas was influenced by the tree species and seasons. NMS analysis of each sampled area showed that soil fungi communities are very homogenous. Ascomycota was the most frequent phylum detected by both dependent and independent cultivation methods. Overall, the communities of cultivable fungi were more related to soil chemical attributes, sampling areas and seasons. Fungal communities accessed by PCR-DGGE showed greater relation with the seasons and tree species where the soil samples were collected. Analysis of metadata using neural network revealed fungal diversity dependence of humic acids, fulvic acids and humin concentrations in soil, as well as pH and organic matter concentrations.

A Mata Atlântica é reconhecida como área de prioridade de conservação na América do Sul, devido ao grande número de espécies endêmicas e constantes ameças à sua biodiversidade em decorrência da substituição da vegetação natural. Embora várias informações sobre a diversidade vegetal e animal estejam disponíveis, pouco se sabe sobre a diversidade de microorganismos existentes no solo desse bioma. A diversidade de fungos do solo foi avaliada em três unidades de conservação da Mata Atlântica do estado de São Paulo: Parque Estadual de Carlos Botelho (PECB), Estação Ecológica de Assis (EEA) e Parque Estadual da Ilha do Cardoso (PEIC). Ao todo, foram analisadas 90 amostras de solo, coletadas em épocas de alta e baixa pluviosidade, e sob a copa de três espécies arbóreas: Cabralea canjerana, Guapira opposita e Maytenus robusta. Foram utilizados métodos independentes (PCR-DGGE e pirosequenciamento) e um método dependente do cultivo (lavagem de solo e filtração de partículas) para a análise da diversidade e estrutura das comunidades de fungos do solo. Os resultados obtidos foram analisados conjuntamente com os dados de atributos químicos do solo e frações da matéria orgânica do solo a fim de verificar suas possíveis relações com as comunidades de fungos. Os resultados obtidos sugerem uma grande diversidade de fungos no solo da Mata Atlântica. Através do método de cultivo, um total de 142 espécies de fungos foi identificado nas três áreas, sendo que a estrutura das comunidades de fungos não foi influenciada pelas espécies arbóreas, mas sim pelas áreas e épocas de amostragem. As comunidades de fungos cultiváveis do PECB e do PEIC foram mais similares entre si do que em relação às comunidades de fungos do solo da EEA, assim como os valores dos atributos químicos do solo dessas áreas foram mais semelhantes entre si. Pelo método de PCR-DGGE, as estruturas das comunidades de fungos das três áreas sofreram influência das espécies arbóreas sob a copas das quais as amostras foram coletadas. Somente a estrutura das comunidades de fungos no solo do PEIC não sofreu influência da época de amostragem. Usando pirosequenciamento, foram obtidas 39.152 sequências da região ITS de fungos, as quais foram agrupadas em 1.800 Unidades Taxonômicas Operacionais (UTOs). A diversidade de fungos na EEA e no PEIC variou em função das espécies arbóreas e épocas de coleta. A análise de NMS de cada área amostrada indicou que as comunidades de fungos do solo são muito homogêneas. O filo Ascomycota foi mais frequentemente detectado, tanto usando metodologia dependente quanto independente de cultivo. De maneira geral, as comunidades de fungos cultiváveis apresentaram maior relação com atributos químicos do solo, áreas e épocas de coleta, e as comunidades de fungos acessadas por PCRDGGE mostraram maior relação com as épocas de coleta e espécies arbóreas sob as quais as amostras de solo foram coletadas. A análise dos metadados usando rede neural revelou uma dependência da diversidade de fungos em relação às concentrações de ácidos húmicos, ácidos fúlvicos e humina no solo, além do pH e concentração de matéria orgânica total. / Brazilian Atlantic Forest is recognized as a top priority for conservation in South America because of its large number of innate species and the threats for the biodiversity due to vegetation changes. Although a plethora of data on plant and animal diversity in the Atlantic Forest is available, the diversity of soil microorganisms in this biome is still mostly unknown. Therefore, soil fungi diversity was evaluated in three Atlantic Forest conservation areas of São Paulo state: Estação Ecológica de Assis (EEA), Parque Estadual de Carlos Botelho (PECB) and Parque Estadual da Ilha do Cardoso (PEIC). A total of 90 soil samples were analyzed, collected in two different seasons (high and low precipitation seasons), and under the canopy projection of three tree species: Cabralea canjerana, Guapira opposita and Maytenus robusta. Two independent cultivation methods (PCR-DGGE and pyrosequencing) and one dependent method (soil washing and particles filtration method) were used for the analysis of soil fungi diversity and community structure. The results of these methods were analyzed together with the data on soil chemical attributes and organic matter fractions in the same samples, in order to verify the possible relations with soil fungi communities. The results suggest a great diversity of soil fungi in the Atlantic Forest. Through the cultivation method, a total of 142 fungi species were identified for the three areas. The structure of fungi communities was not affected by the tree species, but were affected by the sampling areas and seasons. Cultivable fungi community in PECB and PEIC were more similar to each other than in EEAs soil fungi community. In addition, the values of the chemical properties of these areas were more similar to each other. The structure of soil fungi community accessed by PCR-DGGE showed that the three areas were influenced by the tree species under the canopy where the soil samples were collected. Only the structure of PEICs fungi communities was not influenced by the season. By means of pyrosequencing, 39,152 sequences were retained from the ITS rDNA region, which were clustered in 1,800 Operational Taxonomic Unities (OTUs). Fungal diversity in EEA and PECB areas was influenced by the tree species and seasons. NMS analysis of each sampled area showed that soil fungi communities are very homogenous. Ascomycota was the most frequent phylum detected by both dependent and independent cultivation methods. Overall, the communities of cultivable fungi were more related to soil chemical attributes, sampling areas and seasons. Fungal communities accessed by PCR-DGGE showed greater relation with the seasons and tree species where the soil samples were collected. Analysis of metadata using neural network revealed fungal diversity dependence of humic acids, fulvic acids and humin concentrations in soil, as well as pH and organic matter concentrations.

Les sols contaminés par les polluants organiques hydrophobes tels que les Hydrocarbures Aromatiques Polycycliques (HAPs) constituent un problème majeur puisqu'ils sont difficilement éliminés et leurs impacts toxicologiques restent significatifs. Comme alternative aux procédés thermiques et physiques traditionnels, les procédés de lavages de sol in situ et ex situ apparaissent être une solution envisageable et efficace et particulièrement pour les fortes pollutions. Cependant, le traitement des solutions fortement chargées de lavages de sol est une autre barrière à surmonter. Une nouvelle approche combinée est proposée pour répondre à ce problème: les procédés de lavages de sol in situ/ex situ combinés à un Procédé Electrochimique d'Oxydation Avancée Electrochimique (PEOA) avec possibilité de recirculer l'effluent (pour réutiliser l'agent extractant) et/ou de combiner avec un post-traitement biologique (pour minimiser le coût énergétique).L'efficacité d'extraction de l'agent extractant tel que l'hydroxypropyl-beta-cyclodextrine (HPCD) est comparé au traditionnel tensioactif non-ionique dénommé Tween 80, dans les solutions synthétiques et réelles de lavages de sol. Une nouvelle méthode sensible d'analyse du Tween 80, basée sur la fluorescence, est développée pour suivre l'oxydation du Tween 80. Deux PEOAs sont comparés : l'électro-Fenton (EF) et l'oxydation anodique (OA). Les anodes de platine (Pt) (dans le procédé EF) et de diamant dopés au bore (BDD) (dans les deux procédés) sont respectivement utilisées pour étudier la recirculation des effluents et la possibilité d'une combinaison avec un post-traitement biologique. Concernant la réutilisation des agents extractants, l'évolution de la biodégradabilité des solutions et l'énergie consommée (en kWh (kg COT)-1) pendant les PEAOs testés, l'HPCD est trouvée être plus avantageuse que le Tween 80. En revanche, en terme d'efficacité d'extraction, de coût des agents extractants et d'impact sur la respirométrie du sol, le Tween 80 paraît être plus avantageux. En prenant en compte tous ces avantages et inconvénients, le Tween 80 pourrait être retenu comme la meilleure solution / Soils contaminated by hydrophobic organic pollutants like polycyclic aromatic hydrocarbons (PAHs) are a common concern since they are extremely difficult to remove and their potential toxicological impacts are significant. As an alternative to traditional thermal or physical treatments, soil washing and soil flushing processes appear to be conceivable and efficient approaches, especially for higher level of pollution. However, the treatment of highly loaded soil washing/flushing solutions is another challenge to overcome. In that way, a new integrated approach is suggested: soil washing/flushing processes combined to an electrochemical advanced oxidation process (EAOP) in a combination with a recirculation loop (to save extracting agents) and/or a biological post-treatment step (to minimize energy cost).Extraction efficiency of the extracting agent like hydroxypropyl-beta-cyclodextrin (HPCD) is compared to the traditional non-ionic surfactant Tween 80 in synthetic and real soil washing solutions. A new simple fluorescent sensitive and selective quantification method is developed to monitor Tween 80 oxidation. Two EAOPs were compared: electro-Fenton (EF) and anodic oxidation (AO). Platinum (Pt) (in EF process) and boron doped diamond (BDD) (in both treatment) anodes are the respective electrodes employed to recycle effluents and to consider a biological post-treatment, respectively. Regarding the extracting agent recovery, the biodegradability evolution of effluent and the energy consumption (in kWh (kgTOC)-1) during EAOP, HPCD is more advantageous than Tween 80. However, in terms of extraction efficiency, costs of extracting agents and impact on soil respirometry, Tween 80 is much more efficient. By considering all these advantages and drawbacks, Tween 80 could still appear to be the best option

La dépollution des sols contaminés par des hydrocarbures aromatiques polycycliques (HAPs) est un enjeu important de société, à la fois environnemental, économique et technologique, du fait du grand nombre de sites contaminés par ces composés toxiques et persistants. Les entreprises d’ingénierie de l’environnement utilisant des procédés conventionnels de bioremédiation font souvent face à des rendements trop faibles d’élimination des HAPs dans les sols historiquement contaminés. Il y a donc un besoin réel de développer des solutions innovantes.Dans cette étude, 6 sols historiquement contaminés par des huiles de goudron ont notamment été caractérisés par la présence de 42 à 86% des HAPs dans la fraction sableuse, adsorbés sur diverses particules de charbon/coke/bois ou intégrés à l’intérieur de particules d’huile de goudron résinifiées et altérées. Ainsi, en fonction du niveau de séquestration des HAPs, la séparation sélective de la fraction la plus contaminée ou l’utilisation de procédés de lavage de sol (LS) utilisant des surfactants apparaissent comme des alternatives prometteuses aux procédés de bioremédiation. Une attention particulière a ensuite été portée sur le procédé de LS utilisant des surfactants, qui est basé sur l’optimisation du transfert des HAPs du sol vers la solution de lavage. Ce procédé génère des solutions de LS contenant de grandes quantités de surfactants et de polluants. Celles-ci doivent être traitées dans le but d’éviter la contamination de l’environnement et d’améliorer le rapport coût-efficacité du procédé.L’oxydation anodique (OA) a été identifiée comme un procédé adéquat et prometteur pour le traitement de solutions de lavage de sol contenant des HAPs et du Tween® 80 comme agent d’extraction. La compréhension détaillée des mécanismes impliqués dans l’élimination des composés organiques présents dans les solutions de LS a permis de mettre en place deux stratégies de traitement différentes :• Tout d’abord, il a été mis en évidence que l’utilisation de l’OA à des courants faibles et pendant des temps de traitement longs (23 h) permet la dégradation sélective des polluants ciblés (les HAPs) et la réutilisation de la solution de LS pour des étapes supplémentaires de LS. La grande quantité de Tween® 80 ainsi économisée améliore fortement le rapport coût-efficacité et l’empreinte écologique des procédés de LS, en particulier lorsque la séquestration des polluants dans le sol requiert plusieurs étapes de LS et l’utilisation de fortes concentrations en surfactant.• En revanche, des rendements élevés d’élimination des composés organiques et la production de sous-produits plus biodégradables a été observée lors de l’utilisation de l’OA à faible intensité et pendant des temps de traitement court (3 h). Ainsi, des effets synergétiques ont été observés lors de la combinaison de l’OA avec un post-traitement biologique. D’importants rendements d’élimination avec des coûts opératoires optimisés peuvent être atteints. De plus, l’OA peut aussi être utilisée comme post-traitement pour l’élimination des composés faiblement biodégradables. Cette stratégie de traitement a pour but d’éviter toute contamination environnementale par les solutions de LS.Ces deux stratégies de traitement doivent être prises en considération pour une gestion optimale et appropriée des solutions de LS. Au vu des résultats prometteurs obtenus, les défis scientifiques reliés au changement d’échelle de ce procédé ont été discutés / Remediation of soil contaminated by polycyclic aromatic hydrocarbons (PAHs) is an important societal, environmental, economical and technological challenge, due to the high number of sites contaminated by these persistent and toxic compounds. Environmental engineering companies using conventional bioremediation processes often fails to reach sufficient PAH removal rates from historically contaminated soils. Therefore, there is a real need for the development of innovative solutions.In the present work, the characterization of 6 historically tar oil-contaminated soils showed that 42 to 86% of PAH are located in the sand fraction, either adsorbed on various coal/coke/wood particles or integrated in resinified and weathered tar oil particles. Thus, either selective separation of the most contaminated fraction or surfactant-enhanced soil washing (SW) appears to be promising alternatives to bioremediation, according to the level of sequestration of PAHs. Further investigations were performed on the surfactant-enhanced SW process, which is based on the transfer of PAHs from the soil-sorbed fraction to the washing solution. This process generates SW solutions containing a large amount of surfactant and pollutant. They have to be treated in order to avoid environmental contamination and ensure the cost-effectiveness of the whole process.Anodic oxidation (AO) was identified as a suitable and promising process for the treatment of SW solutions containing PAHs and Tween® 80 as extracting agent. The detailed understanding of mechanisms involved in the removal of organic compounds from SW solutions during AO allowed the implementation of two different treatment strategies:• First, it was emphasized that the use of AO at low current intensity during long treatment times (23 h) allows the selective degradation of target pollutants (PAHs) and the reuse of the SW solution for additional SW steps. Thus, the large amount of Tween® 80 saved strongly improves the cost-effectiveness and ecological footprint of SW processes, particularly when the high sequestration of pollutants requires several SW steps using high surfactant concentrations.• In contrast, high removal rates of organic compounds and production of more biodegradable by-products was observed during short treatment times (3 h) by AO at high current intensity. Thus, synergistic effects were observed for the combination of AO with a biological post-treatment. High removal rates with optimized operating costs can be achieved. Moreover, AO can also be used as a post-treatment (polishing step) for the removal of hardly-biodegradable compounds. This treatment strategy aims at avoiding environmental contamination by SW solutions.Both treatment strategies have to be considered for a suitable management of SW solutions. In view of promising results obtained, scientific challenges related to the scale-up of this process were discussed

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.