The explosive 2,4,6-trinitrotoluene (TNT) is currently a main ingredient in munitions; however the compound has failed to meet the new sensitivity requirements. The replacement compound being tested is 2,4-dinitroanisole (DNAN). DNAN is less sensitive to shock, high temperatures, and has good detonation characteristics. However, DNAN is more soluble than TNT, which can influence transport and fate behavior and thus bio-availability and human exposure potential. The objective of this study was to investigate the environmental fate and transport of DNAN in soil, with specific focus on sorption processes. Batch and column experiments were conducted using soils collected from military installations located across the United States. The soils were characterized for pH, electrical conductivity, specific surface area, cation exchange capacity, and organic carbon content. In the batch rate studies, change in DNAN concentration with time was evaluated using the first order equation, while adsorption isotherms were fitted using linear and Freundlich equations. Solution mass-loss rate coefficients ranged between 0.0002 h(-1) and 0.0068 h(-1). DNAN was strongly adsorbed by soils with linear adsorption coefficients ranging between 0.6 and 6.3 L g(-1), and Freundlich coefficients between 1.3 and 34 mg(1-n) L-n kg(-1). Both linear and Freundlich adsorption coefficients were positively correlated with the amount of organic carbon and cation exchange capacity of the soil, indicating that similar to TNT, organic matter and clay minerals may influence adsorption of DNAN. The results of the miscible-displacement column experiments confirmed the impact of sorption on retardation of DNAN during transport. It was also shown that under flow conditions DNAN transforms readily with formation of amino transformation products, 2-ANAN and 4-ANAN. The magnitudes of retardation and transformation observed in this study result in significant attenuation potential for DNAN, which would be anticipated to contribute to a reduced risk for contamination of ground water from soil residues.

Världen står inför ett stort vattenförsörjningsproblem som måste lösas – så många som 884 miljoner människor använder idag potentiellt förorenade vattenkällor till sitt dricksvatten. Denna rapport fokuserar på ett av de drabbade länderna som är Uganda. Syftet med projektet är att undersöka vilket/vilka av de fem olika ugandiska växterna; Erythrina abyssinica, Musa spp, Cyperus papyrus, Imperata cylindrica och Coffea canephora som är mest lämplig för rening av kadmium- och blykontaminerat grundvatten. Katjonbyteskapaciteten bestäms genom laboration. Analyser kring växtmaterialen görs med hjälp av litteraturstudier och intervjuer med en doktorand från Uganda. M. spp visar sig ha klart högst katjonbyteskapacitet och finns även i form av mycket avfall, därför anses denna vara det mest lämpliga materialet för rening. Lösningen skulle kunna implementeras i samhället med ett filter gjort av växtmaterial, om vidare forskning görs. / The world is facing a major water supply problem to solve, as many as 884 million people currently use potentially polluted water sources for their drinking water. This report focuses on one of the affected countries, which is Uganda. The project aims to examine which of the five different Ugandan plants; Erythrina abyssinica, Musa spp, Cyperus papyrus, Imperata cylindrica and Coffea canephora that is the most suitable for purification of cadmium- and lead contaminated groundwater. The cation exchange capacity is determined by laboratory experiment. Literature studies and interviews with a Ugandan postgraduate student are used for the analysis of the plant materials. M. spp has the highest cation exchange capacity and contributes with a lot of waste material; therefore it is considered the most suitable material for purification. The solution could be implemented in the community with a filter made of plant material, if further research is done.

Concrete, the second most consumed material on earth after water, is a source of environmental problems due to global urbanization. The production of this construction material requires a large amount of natural resources, and portland cement (PC) is responsible for around 8 % of planet-warming CO2 emissions. Producing 1 ton of PC will release roughly 1 ton of CO2 into the atmosphere. In 2021, around 92 million metric tons of PC were produced in the U.S., and a total of 4.4 billion tons were manufactured worldwide. While there was a yearly increase of around 1.5 % in the direct CO2 intensity of cement production from 2015 to 2021, urgent annual declines of 3 % until 2030 are necessary to be in line with the Net Zero Emissions by 2050 Scenario. This dissertation presents different approaches and technologies to offset the CO2 footprint of the production of cement clinker, concrete, and cementitious materials in general. First, this dissertation investigated the possibility of using end-of-life tire (ELT) rubber powder and its zinc-recovered residual (treated ELT rubber) to partially replace fine aggregates of different construction and infrastructure materials including stabilized soft soil (0 %, 10 %, 30 %, and 50 % ELT rubber added by clay volume), portland cement concrete (0 %, 10 %, 20 %, and 30 % ELT rubber added by sand volume), and asphalt concrete (20 % ELT rubber added by sand volume). This work was discussed through aspects of engineering properties and environmental impacts. The results reveal that the ELT rubber had both negative and positive effects on the engineering properties of the three materials while this waste posed a huge leachability of zinc and total organic carbon (TOC) content when being subjected to aqueous environments. However, the findings indicate that all three materials' matrices could effectively immobilize most leachable zinc from the ELT rubber by more than 90 %. Meanwhile, only stabilized soft soil and asphalt concrete could effectively deal with leachable TOC content from ELT rubber, and portland cement concrete needed the addition of silica fume to reduce TOC concentration in its leachate. Second, while previous studies have shown that steel furnace slag (SFS) can stabilize clay soils, the evidence is not clear if the stabilization mechanism is chemical and/or mechanical. This dissertation used isothermal calorimetry (IC) to quantify the heat of hydration of the mixture to assess the chemical aspects of the stabilization. Specifically, kaolin and bentonite clays were each blended with 40 % SFS by mass at water-to-binder ratios ranging from 1.0 to 1.5. The hydration properties of stabilized mixtures using lime or PC were also tested for comparison at the same experimental conditions. The obtained thermal power and total heat curves of stabilized mixtures confirmed that, for the specific SFS in this study, there is a hydration process taking place in clay stabilized by SFS. Relative to lime and PC, the SFS performed similarly in terms of heat of hydration behavior. When blended into clays, SFS provided a more significant heat of hydration behavior than cement, but that was much milder than lime. X-ray diffraction (XRD) and thermogravimetric analysis (TGA) were also employed to qualitatively analyze the mineralogy of the stabilized mixtures. Finally, this dissertation adopted a Digestion-Titration Method (DTM) for the determination of CO2 content in cementitious materials that has been mineralized in the form of calcium carbonate (CaCO3). This method was modified based on tests that were originally developed in the early 1900s. The method uses hydrochloric acid to digest CaCO3 under vacuum conditions. The CO2 released is captured by a barium hydroxide solution, which is then titrated to quantify the amount of CO2 absorbed. A design of experiments approach was used to optimize the experimental conditions. Samples of known CaCO3 content were first evaluated to establish the baseline test performance, and additional tests were performed on portland cement and various rock samples. The results were also compared to TGA, including a discussion to compare the two test methods. The data suggest that the new test method is feasibly applicable to chemically determine the CO2 captured in cementitious materials, and it can be an alternative method for TGA with lower experimental cost and easier access. Overall, it is evident that cement, concrete, and construction materials are essential to the functionality of civilization. Dealing with CO2 emissions and natural resource depletion induced by the production of these construction materials is urgent for sustainable development. Attempts toward construction materials with lower embodied CO2 by using low-carbon aggregates (e.g., waste aggregates, recycled aggregates) and alternative cementitious binders while controlling the environmental effects of the utilized waste materials are currently viable sustainable approaches. In addition, tools or new test methods that can support measuring the effectiveness of these reduced carbon cementitious materials are necessary. This dissertation investigates the feasibility of the use of ELT rubber waste in construction materials to reduce the exploitation of natural resources considering engineering properties and environmental impacts. It also provides a deeper understanding of the hydration behavior of stabilized soil using SFS which is expected to partially or fully replace PC in the material. Experimentally, it develops a chemical test model as an alternative method for TGA with lower experimental cost, less interference, and easier access to determine the CO2 captured in cementitious materials. / Doctor of Philosophy / Concrete, the second most consumed material on earth after water, is a source of environmental problems due to global urbanization. The production of this construction material requires a large amount of natural resources, and portland cement (PC) is responsible for around 8 % of planet-warming CO2 emissions. This dissertation presents different approaches and technologies to offset the CO2 footprint of the production of construction materials (i.e., cement clinker, concrete, and general cementitious materials). First, this dissertation investigated the possibility of using end-of-life tire (ELT) rubber powder in different construction materials including stabilized soft soil, portland cement concrete, and asphalt concrete. This work was discussed through aspects of engineering properties and environmental impacts. The results reveal that the ELT rubber had both negative and positive effects on the engineering properties of the three materials. In return, all three materials' matrices could effectively immobilize most leachable zinc and total organic carbon (TOC) from the ELT rubber, which are detrimental to aquatic animals, plants, and humans. Second, this dissertation used isothermal calorimetry (IC) for the first time to study the heat of hydration of soil stabilized by steel furnace slag (SFS) to assess the chemical aspects of the stabilization. The work compared the hydration behavior of SFS in clayey soil with traditional stabilizers such as lime or portland cement. The results demonstrated that there were chemical reactions taking place during the hydration of stabilized soil using SFS, explaining the improvement in engineering properties of the stabilized soil. Moreover, this dissertation adopted a Digestion-Titration Method (DTM) for the determination of mineralized CO2 content in cementitious materials. The method uses hydrochloric acid to digest CaCO3 under vacuum conditions. The CO2 released is captured by a barium hydroxide solution, which is then titrated to quantify the amount of CO2 absorbed. The data suggest that the new test method is feasibly applicable to chemically determine the CO2 mineralized in cementitious materials, and it can be an alternative method for thermogravimetric analysis with lower experimental cost and easier access. Overall, it is evident that cement, concrete, and construction materials are essential to the functionality of civilization. Dealing with CO2 emissions and natural resource depletion induced by the production of these construction materials is urgent for sustainable development. This dissertation is expected to fill the knowledge gap in carbon neutral construction materials research, including increasing the use of low-carbon aggregates (e.g., waste aggregates, recycled aggregates) and alternative cementitious binders as well as developing new test methods that can support measuring the effectiveness of these reduced carbon cementitious materials.

Soil degradation is a common occurrence in Haiti that is mainly caused by the cultivation of marginal lands and deforestation, which both contribute to the excessive erosion rate seen in the country today. The Central Plateau of Haiti is a mountainous region in which a majority of the population is rural and practices subsistence agriculture on hillsides and steeply-sloping land. Essential plant nutrients, such as nitrogen (N) and phosphorus (P), are commonly a limiting factor in crop production, yet fertilizer is unavailable or is too expensive for smallholder farmers to purchase. This study was conducted to a) evaluate organic matter and nutrient stocks of various soils in the Central Plateau region, along with other chemical and physical characteristics and b) to evaluate the phosphorus-scavenging ability of commonly-grown crops to isolate those that may benefit subsequent smallholder yields. Soils from four locations in the Central Plateau were assessed for organic matter in labile and non-labile fractions as well as for cation exchange capacity (CEC), total organic carbon (C) and N, pH, texture, and other characteristics. Results indicated that most of the soil (92%) was contained within aggregates, and organic matter was mainly present in stable, slowly-decomposing fractions. Seven species were evaluated in a controlled-environment pot experiment for bulk and rhizosphere soil P and pH, plant dry weight, and above- and below-ground P tissue content as indicators of the species' ability to solubilize P from the soil. Velvet bean (Mucuna pruriens (L.) DC) produced the most biomass and was able to take up the most P, though lablab (Lablab purpureous (L.) Sweet), took up comparable amounts of P. / Master of Science / LTRA-6 (A CAPS program for the Central Plateau of Haiti)