Academic literature on the topic 'Geo-environmental Engineering'

Geoecological design and expertise accompany socio-economic human activity as a planetary phenomenon. Biogeochemical activity of the state cannot go beyond the environmental barriers that are available to us as a category of land use. As proof, three stages of geospatial platform formation and analysis of extensive models of breakthrough development of one category at the expense of the others are presented. This leads to the accumulation of negative effects, the elimination of which is achieved in the form of infectious epidemics. Cost (as a labor theory) and health (as an economic activity of a person) form the limits of development strategies of an enterprise, economic entity, and the state. Sanitary legislation does not belong to the norms of law, but it forms the beginning of the measurement of space: first in the interests of a man, and then technology and the economy.

Geo-environmental treatment projects had not been implemented in many old mines of China. Those mines environment has got increasingly deteriorated. So the government provides specialized policies and funding to solve the environmental problems of those mines. Based on the characteristics of the geological environmental treatment projects of old mines, the paper puts forward the principle and index of the treatment projects design and applies in the design of Fengshan limestone mine, Guangxi. It indicated that: (1)The geological environment problems are complex and diverse, and the treatment projects involve a multi-disciplinary cross which are environmental geology, ecology geology, geotechnical engineering, environmental engineering and landscape works. It needs to consider the follow key indicators: Geo-environment problems, Feasibility, Benefit, and social demand. (2) the limestone mine in FengShan is high 134m, and there had happened a collapse which had 2.1×104 m3, and killed 6 people. The geo-environment problems include rockfall, rock collapse, land and vegetation destruction, and landscape damage. The mine local in the Leye-Fengshan International Geological Park in Guangxi, the requests for travel security and sight-viewing environment are extremely high. Therefore, drainage, anchoring, rockfalls platforms and rock carvings would be implemented for the purpose of transforming the mine into a sight spot in the park.(3) The treatment projects eliminate the geo-hazard and build the world-class carving attractions reflect the benefit of the project management from the environment, economy and society aspects.

Based on many inquiries, analyses and researches, alternate measures of science and social science are taken in this paper, considering series of geo-environmental effect, and the harmfulness of geological effects in Chongqing main city are analysed. The basic counter measures and managing measures are suggested to treat geo-environmental problems in Chongqing main city so that a long-term plan of city-developing and the objective of a struggle based on real situation are set up. The analytic results are helpful to solve the serious geo-environmental effects, and push forward the study of urban geo-environmental problems of underground engineering in Chongqing.

An engineering geological approach to analysed geo-hazards affecting engineering and planning design decisions is presented. The methodological procedures include hazard identification, hazard assessment, site vulnerability, economic cost, environmental impact, risk assessment, social acceptability, decision analysis and engineering design criteria. The practical application of the Engineering Geological Methodology (EGM) is shown in several case studies: dam safety problems due to slope instability and induced seismicity during reservoir filling; seismic hazard assessment in regions with insufficient seismic data and tectonic information; and large scale geo-hazards due to giant landslides and related tsunamis. The EGM approach can provide fundamental criteria for engineering decisions and territorial planning. Social acceptability should be included in the decision analysis being evaluated according with the hazard level of the geological process and the corresponding risk of the affected elements. Examples of geo-hazards and their social acceptability are presented.

The article deals with the «GP» geo-composite drainage material, which is used in hydro-technical, civil, as well as environmental, industrial and landscape construction. This material is intended for complex application, as a separating, filtering and reinforcing layer in the structures of protective dams on rivers, reservoirs, channels, an earth work of linear transport constructions (automobile and railway facilities) and other hydraulic engineering constructions. It is a combined geo-synthetic material, including a rigid geo-grid of the lattice structure and a filtering geotextile element. As a result of the carried out researches, its basic physical and mechanical characteristics have been established: tensile strength, surface density of geotextile and the material, relative elongation at maximum load, filtration coefficient normal to the material level.

Plastic materials are widely used in geotechnical engineering, especially as geosynthetics. The use of plastic-based products involves serious environmental risks caused by their degradation. Innovative research has been focusing on biodegradable polymers of natural origin, especially on poly(lactic acid) (PLA), to reduce the use of plastics. This study aims to explore the potentiality of biopolymers for the production of geogrids, measuring the chemical and mechanical characteristics of raw materials and of prototype samples, similar to those available on the market. First, chemical composition and optical purity were determined by hydrogen nuclear magnetic resonance (1H-NMR) and polarimetry. Furthermore, samples of uniaxial and biaxial geogrids were custom-molded using a professional 3D printer. Mechanical properties were measured both on the filament and on the prototype geogrids. The maximum tensile resistance was 6.76 kN/m for the neat-PLA filament and 10.14 kN/m for uniaxial prototype geogrids produced with PLA-based polymer mixed with titanium dioxide. PLA-based materials showed higher tensile properties than polypropylene (PP), the most common petroleum derivative. Conversely, such biomaterials seem to be more brittle and with scarce elongation rate respect PP. Nonetheless, these results are encouraging and can support the use of PLA-based materials for innovative biodegradable geosynthetics production, especially if used in combination with live plants.

The presents engineering and environmental surveys on the environmental components such as soil and vegetation cover, atmospheric air, fauna. These surveys are conducted for the new proposed construction sites locating in the floodplain of the Tom River and the terrace above the floodplain. The purpose of the work is to obtain the necessary amount of base-line data for geo-ecological characterization of the current state of the environment. The engineering and ecological surveys show that the considered sites are suitable for a construction and do not provide geo-ecological, economic and social negative consequences.

Geotextiles, a group of high-performance materials, have grown during the last decades into needful auxiliaries when it comes to infrastructure, soil, construction, agriculture and environmental applications. Although geotextiles made of synthetic fibers (geosynthetics) are considered a modern achievement, the basic concept dates back to ancient times when textiles consisting of locally available natural fibers were employed to increase the stability of roads and soils. In recent decades, considering the growing interest in environmental protection and sustainable development based on using renewable resources and the recovery and recycling of waste of various origins, the use of natural fibers-based geotextiles is a viable alternative, despite their limited-life service owing to their biodegradability. In addition to this feature, their low cost, good mechanical properties and large-scale accessibility recommend them for geo-engineering applications, environmental sensitive applications in geotechnical engineering, such as land improvements and soil erosion control. This paper focuses on geotextiles as a versatile tool in environmental applications given their high theoretic and practical relevance as substantiated by recent literature reports. Natural and synthetic geotextiles are presented herein, as well as their features that recommend them for geo-engineering. Insights on the main types of applications of geotextiles are also included, along with a wide variety of materials employed to perform specific functions.

This thesis presents a study of the characterisation of fine aggregates manufactured from waste quarry material and their use in concrete supported by artificial neural network models of the fresh and hardened concrete properties. The reutilization of rock filler, a by-product of the sand manufacturing process, as a soil liming material is explored. A set of tests and techniques were identified to characterise fine aggregates manufactured from quarry dusts via a dry processing system. Granite, limestone, sandstone and basalt manufactured sands and their unprocessed counterparts “feed quarry dusts” were characterised with respect to their shape and texture, grading and quality of fines (presence of clays). The results showed that the reprocessing of quarry dusts improves the particle shape and grading irrespective of rock mineralogy. Plasticised and non-plasticised concrete mixes were developed and the fresh and hardened properties tested. Concrete consistency, compressive and flexural strength is correlated with the fine aggregate characterisation test results. The manufactured fine aggregates showed a higher water demand when compared with natural sand whereas compressive and flexural strengths were enhanced. Artificial neural network models were developed to enable the prediction of the consistency and compressive strength of concrete. These models used the fine aggregate properties and mix composition parameters as input variables and were validated using a separate testing dataset, additional concrete mixes and numerical evaluation. Artificial neural network models were shown to be able to predict fresh and hardened concrete properties based on the fine aggregate characteristics. The excess fillers created in the sand manufacturing process were evaluated for soil liming potential through standard tests and a soil incubation study. The main finding was that materials with high silicate content exhibit a potential for liming, however, a higher dosage is required when compared to the dosage of high purity limestone to achieve the same liming potential.

Two natural soils from Bahrain were used in this study to investigate the feasibility of using Arabian oil residue as a means to stabilize collapsible saline soils. Since the presence of oil residue in soils can pose an environmental threat, the high oil retention capability of the stabilized soils is critical to its application.
The behavior of the stabilized soils has been experimentally investigated in the laboratory. This study has concentrated on the evaluation of the mechanical properties of the stabilized soils, the oil retention characteristics and its bonding mechanisms, and the leaching and migration behaviors of oil residue from the stabilized soils.
The geotechnical investigation results indicated that the addition of 4% oil residue, by weight, was sufficient to significantly enhance the strength performance of the tested soils. The geochemical tests showed that the bonds formed between the oil and the soil surfaces were predominantly Van der Waal's attraction, weak hydrogen bonding, and cation and water bridging. These bonds were found to be relatively weak but stable and insensitive to leaching forces. The geo-environmental results revealed good oil retention in these samples, with less than 3% of the oil residue by weight leached from the stabilized soils after 40 days of leaching in distilled water.
The migration of oil from the stabilized soils has also been theoretically evaluated. The theoretical study utilizes the model developed by Yong et al. (1992) with a few modifications made to accommodate this particular situation. The model was solved using an explicit finite difference method, Powell's optimization technique, and experimental results. The predicted oil migration profiles were found to be slightly over-estimated as compared to the experimental profiles.

A research study has been conducted to simulate liquefaction in saturated sandy soil induced by nearby controlled blasts. The purpose of the study is to help quantify soil characteristics under multiple and consecutive high-magnitude shock environments similar to those produced by large earthquakes. The simulation procedure involved the modeling of a three-dimensional half-space soil region with pre-defined, embedded, and strategically located explosive charges to be detonated at specific time intervals. LS-DYNA, a commercially available finite element hydrocode, was the solver used to simulate the event. A new geo-material model developed under the direction of the U.S. Federal Highway Administration was applied to evaluate the liquefaction potential of saturated sandy soil subjected to sequential blast environments. Additional procedural enhancements were integrated into the analysis process to represent volumetric effects of the saturated soil's transition from solid to liquid during the liquefaction process. Explosive charge detonation and pressure development characteristics were modeled using proven and accepted modeling techniques. As explosive charges were detonated in a pre-defined order, development of pore water pressure, volumetric (compressive) strains, shear strains, and particle accelerations were carefully computed and monitored using custom developed MathCad and C/C++ routines. Results of the study were compared against blast-test data gathered at the Fraser River Delta region of Vancouver, British Columbia in May of 2005 to validate and verify the modeling procedure's ability to simulate and predict blast-induced liquefaction events. Reasonable correlations between predicted and measured data were observed from the study.

PUMPS mimics natural geothermal vents as a conceptual model designed for the remediation of acid mine water (AMW) in voids of abandoned gold mines of the Witwatersrand Basin in South Africa. In this system, a reaction chamber containing Desulfotomaculum kuznetsovii sulfate reducing bacteria will be set at the bottom of a 3-4 km deep mine that will be flooded. A geothermal system with at least one (1) doublet will be drilled from the bottom of the mine to the depth of 8km, where the temperatures are sufficient for geothermal energy harvesting. AMW, used as a geothermal fluid, will be pumped down the injection well and circulate through hot rock. The hot water is then used to generate electricity and then channelled into the reaction chamber to undergo bio-remediation. Following treatment, the water flows back into the mine voids where it will improve the quality of untreated AMW through dilution. Eventually, the mine will be flooded with clean water that can be stored underground and/or pumped up to surface for social and ecosystem services. Following an introduction and proof of concept for the PUMPS, the research builds further on the technical and economic evaluation of the PUMPS in order to assert its viability and sustainability. The technical viability includes testing the ability for Desulfotomaculum kuznetsovii to survive in high pressure condition; quantifying the amount of energy that can be drawn from the geothermal reservoir; determining the placement and scheme of the geothermal wells; and, finally, developing a robust economic model of the system. Experiments show that Desulfotomaculum Kuznetsovii can tolerate high pressure conditions in of at least 100bar at their ideal sulfate reducing temperature of 63°C. Geochemical modelling shows that AMW can be used effectively as a geothermal fluid for PUMPS. To achieve highest efficiency and minimal fluid loss, the geothermal wells should be placed along the SSE-NNW direction, based on the known stress field across the Witwatersrand Basin. With a flow rate of 30l/s the energy drawn from the geothermal reservoir is sufficient to drive PUMPS and the surplus energy is determined by the volume of AMW treated per day. All results indicate that the PUMPS is technically and economically viable. The economic model shows that the value and viability of the PUMPS is best reflected with a comprehensive inclusion of potential revenue (for example from chemical solution mining of deep seated gold) and financial/environmental incentives.

Clays are used for long for the control of soil and water pollution as they are inexpensive natural materials with a high adsorption capacity for a wide range of pollutants. However their use as components in engineered waste containment systems is often limited when it comes to the control of organic contaminants as the clays are organophobic in nature. Organic modification of the natural clays, by replacing the exchangeable inorganic cations of clay with organic cations, can facilitate to overcome this limitation. On modification the clays become organophilic which can enhance their sorption capacities for organic contaminants. There are several ways by which natural clays can be modified with organic cations. The type of clay, the type of modifier, and the extent of modification play an important role in enhancing the organic sorption capacity. Sorption of organics by the organo clays depends on a large extent on the specific interactions that occur between modified clay and the organic contaminants. The interaction between the clay and the contaminants depend on the physico-chemical properties of modified clay and nature of organic contaminants. Since the properties of natural clays are likely to be altered by the modification a detailed study has been taken up to understand the physico chemical characteristics of organo clays which essentially control their organic sorption efficiency. Apart from bentonite which is widely used as a component of barrier systems, the characteristics of other types of clays on organic modification also needs to be assessed as they can also form part of the containment system frequently. Further the modification of clays is bound to bring in significant changes on their geotechnical properties which may affect their performance when used as barrier material. Only limited research has been conducted in the past on the geotechnical characteristics of organo clay. Therefore extensive studies have been carried out on the evaluation of the geotechnical characteristics of organo clays and the effect of organic modification on important geotechnical properties. Since very often inorganic and organic contaminants can occur simultaneously, admixtures of bentonite and organically modified clays needs to be employed as a part of clay barrier system. Moreover clay alone is very rarely used as component of barrier systems and significant portion of barrier material usually include non clay fraction. Hence studies have been carried out on mixtures containing different proportions of organo clay and bentonite and sand – organo clay / bentonite to evaluate their geotechnical behavior. Important geotechnical properties considered for detailed studies are swelling, compressibility and permeability. Detailed studies on the organic sorption capacities of different organically modified and unmodified clays, mixtures of bentonite and organo clays have also been conducted. The results of studies conducted are presented in 9 chapters. The organization of the thesis is as follows: Chapter 1 gives detailed background information on the sources and hazards of organic contaminants, inadequacy of conventional barriers to contain organic contaminants, the need for modification of natural clays, and the methods for organic modification of clays. Extensive review of literature has highlighted the need to study the effect of organic modification on the physico chemical and geotechnical properties of clay in different pore fluids. Organo clays were prepared using a wide range of clays viz., two types of bentonites of different regions, black cotton clay and commercially available kaolinite with a long chain organic cation. The extent of organic modification was varied by varying the amount of organic cation exchanged as function of total cation exchange capacity of the clays. Detailed physico chemical characterization of these modified and unmodified clays has been carried out with the help of different state of art techniques. The Chapter 2 brings out the effect of modification, role of type of clay and type of modifiers on the characteristics of organo clays by comparing the physico chemical characteristics of different modified and unmodified clays. The organic modification of montmorillonitc clays with long chain organic cation is found to increase their lattice spacing with the amount of modification whereas no such increase was observed on modification of kaolinitic clays even when all the exchangeable inorganic cations were replaced with the organic cations. The XRD studies revealed that the intercalated organic cations of the modified montmorillonite clays assumed mono, bi, or pseudo tri layer depending on the extent of organic modification. Irrespective of the type of clay modified or the modifier used all the organo clays tend to become e hydrophobic, and the surface area of the clays was found to decrease. A comparison of the characteristics of clays modified in laboratory with organo clay obtained commercially revealed that the organic modification was more effective for the organo clay prepared in the laboratory. As the index properties of all clays are generally correlated with their geotechnical characteristics, the effect of organic modification on the index properties of clays was studied. Chapter 3 presents the effect of organic modification on the plasticity and free swell behavior of clays. The index properties of commercially available organo clay and the unmodified clay used for its preparation were evaluated with pore fluids of different dielectric constants. Fluids of varied dielectric constants were chosen as it is one of the important characteristics to understand the behavior of clays. It was observed that the organic modification of clays reduced the plasticity of the clays in water and increased the plasticity in less polar liquids like ethanol. As the organo clays are more hydrophobic, the water holding capacity and plasticity in water is decreased to a large extent. The free swell behavior of clays in different pore fluids were assessed in terms of the modified free swell index. It was found that trend of variation of free swell index with dielectric constant for modified and unmodified clays, as in the case of plasticity is quite opposite. The swell volume of the modified clays was observed to be controlled more by surface solvation than by the development of the inter particle repulsive forces and diffused double layer. The effect of incorporating unmodified bentonite with organically modified clay on the index properties of bentonite has also been studied. The results suggested that the effect of organo clay addition to bentonite was always to reduce its plasticity and free swell in water. However in pore fluids of lower dielectric an increase in the plasticity and free swell was observed with increasing organo clay content in the mixture. This owes to the fact that organo clays can interact strongly with organic fluids, changing its fabric arrangement. As reported from literature it is well established that the swell of clays has conflicting role on the stability and permeability of clay barriers. Swelling of clays is liable to cause a reduction in hydraulic conductivity, enhance the retention times of contaminants and attribute self healing capacity to the liners. Even though extensive studies have been carried out on the swell behaviour and mechanism of swell of unmodified clays, no systematic research is reported on the effect of organic modification on swell behavior of clays especially in the presence of different pore fluids. Chapter 4 describes the results of oedometer swell tests carried out on compacted samples of modified, unmodified clays and organo clay –bentonite mixture in the presence of different pore fluids such as water, ethanol, and their mixture and carbon tetra chloride. Swelling ability of the unmodified clays was not completely suppressed even in the presence of low polar miscible organic liquids as they were molded at water contents corresponding to the optimum moisture content (OMC). The order of the swelling for the unmodified bentonites was in the order of the polarity of the pore fluids used, while the order is reversed upon organic modification of clays. The mechanism of swell in the case of organo clays in organic liquids was related to the solvation of the organic liquid by the intercalated organic cations. And unlike in the case of unmodified clays, the organo clays showed “solvent induced swelling”. Both organic modification and addition of organo clay to bentonite resulted in the suppression of the swelling of clays in water irrespective of the type of modifier or the extent of organic modification. The Chapter 5 gives a detailed account of the compressibility behavior of organically modified clays and its mixtures with bentonite when the samples were molded with water at their respective OMC and later inundated with different fluids. Significant differences were observed on the compressibility of modified and unmodified clay in different fluids. Organic modification of clays reduced their affinity to water and resulted in lowering the compressibility. However there was an increased compressibility for the organo clays when the samples were inundated with non polar liquids and the compression of the organo clay in non polar fluid was not influenced by the nature of clay nor by the type of modifier. The compressibility of the mixtures of organo clay and bentonite in non polar liquids was generally controlled by the organo clay component of the mixture. Organo clays can be recommended as additives in bentonite slurries for construction of slurry walls in order to improve the containment of organics. But the amendment should not compromise the stability and integrity of the slurry walls. Moreover the influence of addition of sorptive material like organo clay on the compressibility behavior of bentonite slurry has received little attention and needs serious consideration as the studies in the previous chapter has brought out that the compressibility of compacted bentonite reduced significantly on organic modification as well as on addition of orgno clay. The Chapter 6 deals with the compressibility behavior of slurries of unmodified bentonite, organo clay, and their mixtures molded with respective liquid limits with water and later inundated with fluids of different dielectric constants as the slurries frequently get in contact with fluids other than water during their operational life. However it was observed that the effect of polarity of the inundating liquid is masked in all the cases by the presence of large amount of initial molding water as the possible specific chemical interactions between organo clay and non polar fluids were restricted in the presence of large amount of molding water. But the slurry samples molded and inundated with non polar carbon tetra chloride showed that the organo clay samples are more compressible when molded with carbon tetrachloride. The chapter also gives a brief discussion on the effect of initial molding water content on the compressibility of organo clays and its mixtures. The compression was found to increase with increase in initial water content irrespective of the type of inundating fluid in agreement with the behavior observed in the case of unmodified clays. However the effect was less pronounced at higher applied pressures. The Chapter 7 brings out the volume change behavior of organo clay amended sand bentonite mixtures (SOB) which form potential barrier to prevent and /or remove contaminants. The compaction behavior of mixtures showed that the degree of compaction achieved was controlled mainly by the sand content and proportion of organo clay in the total fine fraction. The volume change behavior of the SOB mixtures were assessed with the help of oedometer tests conducted on mixtures compacted at OMC conditions and inundated with different fluids same as those used for the swell tests. The samples with higher sand content showed no observable swell when inundated with liquids viz., water, ethanol and their mixture as all the swollen finer particles were accommodated in the voids created by sand particles. However a high swell percentage was measured when samples with high organo clay content were inundated with carbon tetrachloride. Moreover with increased amounts of organo clay in the mix the swelling of bentonite was suppressed and the same trend continued even when the pore fluids were changed to liquids of medium polarity. The organo clays are capable of interacting strongly with non polar liquids like carbon tetra chloride, and hence an appreciable swell was noted when inundated with them especially in the case of mixtures with high organo clay content. The swell behavior of SOB mixtures with lower sand contents were controlled mostly by the interaction of the pore fluid with bentonite and organo clay, interactions between organo clay and bentonite and the polarity of the pore fluid. As the pore fluid polarity was decreased the influence of organo clay component of the mixture was more pronounced. The Chapter 8 explains the hydraulic performance of modified and unmodified clays along with that of the mixtures of organo clay with bentonite and SOB. The coefficient of permeability was calculated from the consolidation data obtained on sample molded at OMC. The permeability variations observed on changing the pore fluids were studied at each applied pressure. The hydraulic conductivity showed a decreasing trend with the increase in applied pressure for all the clays. The specific interactions of the organo clay with the pore fluids and the clay content were found to play a role in controlling the permeability. Limited tests were carried out to simulate a condition where a SOB liner is proposed as a secondary liner below a punctured geo membrane and its hydraulic performance was evaluated with diesel and water as pore fluids. The permeability coefficients with diesel as permeant were observed to decrease with increase in organo clay content of the mixture irrespective of the applied pressure where as the reverse was true when permeated with water. Thus the use of SOB as secondary liner below storage tanks so as to control the transport of contaminants leaking containments systems is established. The organic sorption efficiency of the modified and unmodified clays and the mixture were evaluated in terms of removal of total organic carbon (TOC) and reduction in chemical oxygen demand (COD) of the different leachates including municipal solid waste (MSW) leachate when treated with different types of modified and unmodified clays. All the modified clays irrespective of the type of clay or the type of modifier used showed improved organic sorption capacity. The sorption of TOC was found to follow a linear sorption mechanism in the case of organo clays and the organic contaminants were partitioned on to the organic phase attached to the organo clays. The composition, age and type of leacahte played a major role in controlling the organic sorption efficiency of organo clays in the case of MSW leachates. The studies done with different mixtures of organo clay and bentonite and SOB mixtures clearly proved that the addition of organo clay always enhanced the organic sorption efficiency of the mixtures. The results are discussed in Chapter 9. The Chapter 10 highlights the major conclusions drawn from the study. The study, apart from satisfying the research zeal on understanding the behavior of organo clays, has generated important information useful for the geo environmental engineer to arrive at appropriate design of barrier systems incorporating organically modified clay, based on the characteristics of pore fluid.

Rising concentration of CO2 in the atmosphere is attributed to increasing consumption of fossil fuels. One of the most effective mechanisms to store CO2 captured from power plants is via geological injection of CO2 into formations that contain calcium and magnesium silicate and alumino-silicate minerals and rocks. The mechanism that ensures permanent storage of CO2 within rocks is mineral carbonation. When CO2 is injected into mineral or rock formations rich in calcium or magnesium silicates, they react with CO2 to form calcium or magnesium carbonates, which is also known as carbon mineralization. Calcium and magnesium carbonates are stable and insoluble in water. However, the kinetics of in-situ mineral carbonation involve CO2 hydration, mineral dissolution and formation of carbonates, and the relative rates of these phenomena when coupled, are not very well understood. In this study, the coupled interactions of CO2-reaction fluid-minerals were investigated to determine the optimal conditions for carbon mineralization, and to identify the chemical and morphological changes in the minerals as they react to form carbonates. Carbon mineralization in various minerals and rocks such as olivine ((Mg,Fe)2SiO4)), labradorite ((Ca, Na)(Al, Si)4O8), anorthosite (mixture of anorthite (CaAl2Si2O8), and basalt (rock comprising various minerals) were studied at high temperatures (Tmax = 185 oC) and high partial pressures of CO2 (PCO2, max = 164 atm) which are relevant for in-situ conditions. These minerals and rocks differ considerably in their chemical compositions and reactivity with CO2. A systematic comparison of the effects of reaction time, temperature, partial pressure of CO2, and fluid composition on the conversion of these magnesium and calcium bearing minerals and rocks showed that olivine was the most reactive mineral followed by labradorite, anorthosite, and basalt, respectively. Previous studies at Albany Research Center (Gerdemann et al., 2007; O'Connor et al., 2004) reported that a solution of 1.0 M NaCl + 0.64 M NaHCO3 was effective in achieving high extents of carbonation in olivine, heat-treated serpentine, and wollastonite. However, the independent effects of NaCl and NaHCO3 and their role in mineral carbonation were not sufficiently explained. In this study, the role of varying concentrations of NaCl and NaHCO3 on carbon mineralization of various minerals was elucidated. NaHCO3 buffered the pH and served as a carbon carrier, resulting in higher carbonate conversions. Except in the case of olivine, NaCl had a negligible effect on enhancing mineral carbonation. Unlike NaHCO3, NaCl does not buffer the pH or serve as a carbon carrier, but Cl- may serve as a weak chelating agent can complex with Mg or Ca in the mineral matrix to enhance dissolution. The competing effects of ionic strength and pH swings as the mineral dissolves and carbonation further complicate the role of NaCl on mineral carbonation. Based on the experimental methodologies developed to study carbon mineralization in minerals and rocks at high temperatures and pressures, alternative applications such as the remediation of hazardous alkaline wastes such as asbestos containing materials were identified. Asbestos is composed of chrysotile, a fibrous hydrated magnesium silicate mineral and a form of serpentine known to cause respiratory illnesses. By treating asbestos containing materials with CO2 in the presence of 0.1 M Na-oxalate, dissolution of chrysotile and precipitation of newer phases such as glushinkite (Mg(C2O4)* 2H2O) and magnesite (MgCO3) occurred, which reduced the chrysotile content in asbestos. Based on the methodologies for studying mineral dissolution and carbonation kinetics, and coupled mineral dissolution and carbonation behavior, a scheme for connecting laboratory scale experiments with simulations to estimate the uncertainties associated with carbon mineralization was developed. The effects of temperature, different dissolution rates, and varying levels of surface area changes due to passivation or reactive cracking on the rates of carbon mineralization were simulated using PhreeqC, a computer program developed for geochemical speciation calculations (Parkhurst & Appelo, 1999). Various studies proposed that microfractures and cracks may occur in geologic formations due to the extensive growth of carbonate crystals (Kelemen & Hirth, 2012; Kelemen & Matter, 2008; Matter & Kelemen, 2009; Rudge et al., 2010). Other studies have suggested that the formation of carbonates may plug the pore spaces and limit further reactivity (Hövelmann et al., 2012; King et al., 2010; Xu et al., 2004). The effects of changes in surface area due to the formation of microfractures or passivation due to carbonate growth on the rates of carbon mineralization were also simulated. Overall the results of these studies demonstrate the effect of various parameters on carbon mineralization and how these parameters can be connected to predict CO2 storage in mineral formations. The frameworks to connect laboratory scale experiments with simulations to determine carbon mineralization rates and to assess the risks associated with CO2 injection in reactive formations, can be used to direct future research efforts to predict the fate of injected CO2 with greater accuracy for sensor placement and optimization of CO2 monitoring technologies.

Wetland land system is the natural way for the treatment of wastewater. Constructed wetland system (CWs) is a traditional way for treatment. CWs are considered as secondary or tertiary treatment systems. CWs provide good landscape and better habitat quality for the community. Various types of media are used in Constructed Wetland Systems. Literature shows that various soils have the potential to filtration medium (in substratum) in Horizontal Flow Subsurface Constructed Wetland System (HFSCWs) for wastewater treatment. Soil should have few environmental and geo tech properties. Soil provides the root zone in rhizome network for the vegetation in CWs. Soil provides the absorbent media not only in the HFSCWs but Vertical Flow Constructed Wetland system (VFCWs) also. As per Environmental Protection Agency (EPA), various properties of filter media were described. This review base on types of commonly used wetland, filter media, plant use and geo physicochemical parameters of filter media.

Abstract Construction in the extreme cold regions becomes one of the important businesses in the world. Geophysical surveys, which are effective in providing consecutive ground information, have been widely applied to the civil engineering and environmental sectors. The permafrost area covers about 14 percent of the world’s land area and the global construction market for such area is rapidly expanding. Where developed countries have already recognized the need for research of the coldest places and therefore have invested heavily in technology development, the non-arctic countries are still developing and related research has rarely been performed. The purpose of this study is to design the GIS (Geophysics Information System) platform for a construction environment with a 2,000 km-class pipeline (overland) operated under the permafrost temperature conditions (−40°C∼+20°C). The GIS platform when subjected to geotechnical engineering provides an understanding of the frozen ground and information about the geo-environment of the extreme cold regions. This paper shows the characteristics and procedures of Environmental Impact Assessment (EIA) for developing Arctic resources, and reviews how to construct a system for the systematic management of the necessary information to consider building the GIS platform. In addition, this study introduces the GIS algorithm to build the route for the pipeline path, and factors which should be considered first are safety, environment, economic feasibility and technical feasibility.

Abstract The oil and gas industry needs continuously improving in the exploration and extraction methods with a special care and strong compromise to maintain the equilibrium with environment. Based on that mission, and in compliance with the Parex Resources Greenhouse Gases and Climate strategy, Parex Resources executed the first multilateral drilling project in Colombia. It was an ambitious and challenging exploration campaign. The goal was to improve the exploration area by drilling multiples branches through different geological units and total vertical depths (TVD) into an overpressured naturally fractured field. The field presented a complex geological and structural environment. Expectations were high for both drilling optimization and formation evaluation of a compartmentalized reservoir, looking to cover the highest extension while drilling fewer wells from the surface. Considering the level of the challenge ahead, the solution was articulated in three critical fronts:Develop a vigorous planning with service company and operator engineering team for casing design, mud weight window and system, bottomhole assembly (BHA) design, and fit for purpose technology for directional drilling operations.Include a full set of logging data with reliable logging-while-drilling (LWD) tools and advanced mud logging services to fulfill geology requirements, as no wireline logging was planned due to constrains in a horizontal borehole.Implement well placement services with the most experienced team to geo-steer based on real-time data completely integrated for precise interpretation. The operational efficiency achieved was beyond expectations in all areas of well construction, not to mention the project cost reduction through the multilateral approach, preventing to drill three wells from surface. In this case, three different geological compartments were explored from one surface location. This innovative exploration approach also brought important gains on the environmental impact as surface operations were dramatically minimized compared to conventional exploration. This strategy helped the operator and service company to reduce the carbon footprint, simply by reducing the number of wells and operational days needed to explore new fields.

Because pipeline routing, design, and permitting is complex and often controversial, it is advantageous to utilize new technologies to expedite the overall process. Potential pipeline routes can be modeled in a Geographic Information System (GIS) to facilitate early identification of engineering and environmental constraints. This allows time for preliminary engineering and permitting, avoiding time-consuming and costly re-routing later on. Why take the planning, design, and permitting into a virtual world? A primary advantage of a virtual GIS model is based on the way humans process information. It is estimated that 50% of the brain’s neurons are involved in vision. Two-dimensional (2D) and three-dimensional (3D) visualizations simulate spatial reality, thus allowing the viewer to quickly recognize and understand complex concepts such as changes in elevation or tree growth over time. This is especially true of 3D displays, which involve a larger portion of the brain in the problem solving process (Swanson, 2002). Using spatial visualizations—or geo-visualizations—engineers, planners, and environmental scientists involved in pipeline permitting can quickly and easily identify engineering and environmental constraints along a route and may be more effective in conveying their plan to stakeholders. Many pipeline routes are inaccessible due to either rough terrain or restricted access. Virtual routes can be evaluated by the design team without each team member travelling to the project location, saving valuable project time and reducing project budget. Once a GIS model for the entire route is created, 2D and 3D illustrations allow a project proponent to “sell” a particular alternative or project mitigation to permitting agencies and stakeholders, and potentially accelerate the overall permitting process.

The integration issue of virtual models and geo-referenced database have a very broad spectrum of potential applications. Before the integration issue was on the cusp, it was quite problematic to combine three-dimensional models with the geo-referenced database. An integrated database contains a variety of data including such as object orientated data model and raster data. Within this paper, authors present an integration process aiming to make real virtual GIS database which includes the creation of structures, such as bridges, buildings, roads and terrain formations. To create a three-dimensional GIS model high-resolution satellite images/point cloud has been used. For 3D modelling and reconstruction purposes, The Blender program has been used since the software provides with quick workflow and userfriendly interface. As a result of this study authors concede that integrated techniques for three-dimensional GIS databases allow conducting easy as well as sophisticated operation in an efficient and non-time consuming way. The subject holds great promise for a future, current challenges focusing on new approaches for conjectures of spatial objects that will be used to boost the capabilities for automatic visualization.

The offshore oil and gas industry spends over $60bn per year on oil and gas wells and of this some $6bn, or around 10% is eaten up by geological and geotechnical problems such as stuck pipe, lost circulation, well bore instability, shallow water flows and other problems. On top of this are the environmental costs of the oil spills that can result from lost well control, and perhaps most importantly the human costs in terms of injuries and loss of life resulting from some of the worst incidents. This paper lists the geohazards within and around a well, the drilling risks implied by these geohazards, and the impact they can have on the planning and drilling of offshore wells. Current practice in geophysical and geotechnical site investigation techniques which, when correctly applied and interpreted, can help to reduce the risks and costs associated with the ‘Top-hole’ section is summarised and discussed (the Top Hole section is defined as the depth to the base of the first pressure containment string). Finally, a systematic approach to assessing and mitigating top-hole geo-risks through a multi-disciplinary geoscience and engineering approach is described. The authors are members of a working group of the Offshore Site Investigation and Geotechnics (OSIG) committee of the Society of Underwater Technology (SUT) who are drafting guidelines on the subject.

The article highlights peculiarities of geoinformation technologies’ application in course of pre-service engineers’ training for sustainable development, their functionalities, geoinformation system’s role and position in environmental protection acts. Concepts of geoinformation technologies, geoinformation system have been disclosed. The pedagogical experiment was done concerning introduction of the developed method of using geoinformation technologies as means of forming environmental competence profile mining engineers predicted an experemental studying on course «Environmental Geoinformatics». The results of the expert assessment of rational using geoinformation technologies there were given to create an ecological competence of future mining engineering profile.