<p> Jar testing is one of the most common tools that water treatment facilities use to determine the treatment conditions necessary to meet finished water quality goals. A six-place stirrer is normally used for jar testing to provide identical mixing conditions while coagulant dose and pH vary in each jar to create &ldquo;floc&rdquo; that is removed via sedimentation. There are some utilities that are unable to utilize jar testing, since the current jar testing procedures do not identify optimum treatment conditions for their water supply. This is particularly true for those utilities treating low-turbidity, low-TOC waters because low coagulant doses can produce small floc that does not settle efficiently (even though it is removed efficiently by filters). A modified jar test procedure was developed with the goal of providing consistent and reliable results for all treatment facilities without having to make site-specific changes to the mixing speeds and times to try to match the plant performance. Instead of sedimentation, the modified jar test procedure uses a novel granular media filter along with a standardized mixing protocol and titrations to predict and control the pH of the coagulated water. Contour mapping of jar test data was utilized to provide a detailed visual description of zones of effective treatment. Research found that the application of direct filtration (instead of traditional sedimentation) reduced testing time and showed better correlation to treatment plant performance. A method of optimizing coagulant dose and coagulated pH based on titrations is proposed, which is based on an alternating, single-variable optimization method with experimentally determined starting points. Treatment with coagulant only (i.e., without prior pH adjustment) limits the range of coagulation conditions a water treatment plant can operate at. Coagulants are acidic and their addition during treatment causes both the pH and coagulant dose to change simultaneously. Treating water with coagulant only provides only one diagonal path for treatment to occur across a two-dimensional area of pH and coagulant dose combinations, which sometimes misses optimal treatment conditions entirely.</p><p>

Bench-scale systems, if properly designed, can become a valuable tool to evaluate fouling in dead-end ultrafiltration systems. The purpose of this study was to design and build a bench-scale hollow fiber ultrafiltration system to examine the effect of operational parameters and chemical pretreatment on membrane performance. For this research, a bench-scale hollow fiber ultrafiltration system that operates at constant flux and includes a backwash cycle was designed and built. The system was also designed to be used as a tool in the evaluation of critical flux for source waters. The study demonstrated that shorter operating time between backwash cycles resulted in reduced membrane fouling, improved backwash efficiency and natural organic matter rejection. The study also indicated that fouling rate increased with increase flux while backwash efficiency decreased with increasing operating flux. Chemically pretreated ORW showed superb reduction in normalized specific flux decline when compared with uncoagulated ORW.

The impact of aging in the presence of reactive gases (i.e., carbon dioxide and oxygen) on the physical and chemical microstructure of microconcretes and cast stone cementitious waste forms prepared with different fly ash types was investigated. Geochemical speciation with reactive transport modeling was also performed for the microconcretes to better understand and predict the leaching behavior of cementitious materials after aging. The alkalinity of microconcrete materials due to the fly ash replacement type was found to impact the rate and extent of carbonation and the relative changes in the pore structure within the bulk and interfacial transition zone regions. Migration and deposition of constituents was observed within the microstructure of microconcrete materials in response to changes in constituent solubility due to carbonation. A common mineral and solid solutions reaction set can be used in the geochemical speciation with reactive transport modeling to describe the leaching behavior of non-carbonated and carbonated microconcretes with different fly ash replacement types, with some identified limitations. A multi-ionic diffusion approach and consideration of the minerals controlling solubility at a low liquid-to-solid ratio was required. For cast stone cementitious waste forms, the changes in the mineralogy and the microstructure that occur as a result of carbonation are different from what has been observed for cementitious materials with larger amounts of Portland cement. Oxidation and carbonation were also found to influence the mass transport of constituents due to changes in constituent solubility, material pH, and porosity.

Cesium (137Cs) and technetium (99Tc) are two radionuclides of significant concern in spent nuclear fuel because of their long half-life, high decay energy, and high solubility. Cementitious materials are considered as potential candidates for nuclear waste immobilization. The study of the interaction of radionuclides with the cement matrix is thus essential to determine the capability of cementitious materials to immobilize radioactive isotopes such as 137Cs and 99Tc. Calcium-silicate-hydrate (C-S-H) and calcium-aluminate-sulfate hydrate (ettringite) are two main products of cement hydration in Portland Cement (PC). The interactions of CsCl solution with different crystalline C-S-H structures (9Ã tobermorite, 14Ã tobermorite and jennite) and the interactions of KTcO4 solution with crystalline C-S-H structures (14Ã tobermorite and jennite) and ettringite were studied using Molecular Dynamics (MD) simulations. MD simulation results indicated that Cs+ ions were mainly adsorbed as inner-sphere complexes at the tetrahedral SiO4 surface ((0 0 1) plane) of 9Ã tobermorite, 14Ã tobermorite, and jennite. The tobermorites showed higher adsorption capacity of Cs+ ions than jennite. Jennite had weak affinity to Cs+ ions. MD simulation results indicated that TcO4- ions can be adsorbed on the surfaces of 14Ã tobermorite and ettringite. On the octahedral CaO6 surface ((0 0 -1) plane) of 14Ã tobermorite, inner-sphere Tc complexes coexisted with outer-sphere Tc complexes. Co-ion adsorption affected the adsorption of outer-sphere Tc complexes and pushed outer-sphere complexes further away from the surface. On the octahedral CaO6 surface ((0 0 -1) plane) of ettringite, TcO4- ions were mainly adsorbed as outer-sphere complexes. Two types (i.e. type 1: tetragonal geometry and type 2: tetrahedral geometry) of outer-sphere Tc complexes were predicted on both surfaces of 14Ã tobermorite and ettringite. Jennite had no affinity to TcO4- ions. In conclusion, 9Ã tobermorite and 14Ã tobermorite were better candidates for the immobilization of Cs+ ions than jennite. Ettringite and 14Ã tobermorite also showed better affinity to TcO4- ions than jennite. Ca2+ ions on the surface played an important role and formed complexes with TcO4- ions.

<p> The Mauch Chunk Group has been interpreted as a product of multiple transgressions and regressions (Miller and Eriksson, 2000; Beuthin and Blake, 2004). An outcrop containing the upper Hinton Formation and Princeton Formation, the middle two formations of the Mauch Chunk Group, occurs along US-460 in Princeton, West Virginia, 2.6 kilometers east of the Interstate 77 Princeton exit. In order to understand the sedimentology and depositional history at those outcrops, sedimentologic logs were compiled, facies were identified and bundled into facies associations, photographic panoramas with line drawing overlays were constructed, and rock samples were taken. From the logged sections and facies architecture, a depositional history was interpreted. That history was supplemented with a provenance study where the samples were analyzed with a scanning electron microprobe to document oxide weight percentages. The upper Hinton Formation and the Princeton Formation were deposited through a combination of autocyclic and allocyclic processes. The mineralogy does not conclusively tie the sandstone deposits to the same source; however, mineral identifications did indicate the provenance to be an area with both igneous and metamorphic rocks. The presence of growth faulting indicates that the location of the cross-bedded sandstone that comprises the Princeton Formation at the US-460 outcrop may have been influenced by syn-depositional tectonism.</p><p>

Water is an important resource for various societal needs, with agriculture accounting for 70% of global freshwater withdrawals and 90% of global water consumption. Due to increasing constraints from climate change (among other factors), improved and efficient management of current resources will be critical to continued growth. Given that agriculture production is embedded in a coupled natural and human system, sustainable management analysis of water-related decision making requires incorporation of economic and psychological factors in addition to natural resource factors. Using Sri Lanka as a case study, this dissertation research combines physical insights with social knowledge about crop cultivation to inform assessments of climate change adaptations. Specifically, we characterized spatiotemporal patterns of agricultural drought in the country over the last 130 years, identified the value of shifting the planting date for rice (the staple food of the country), and evaluated the use of seasonal weather forecasts to guide farmer crop selections. Our analysis highlights that while policies and programs that promote production of certain crops may ensure food security in the short-term, the long-term implications of these dynamics need careful evaluation.

D.Phil. / "We would be foolish to ignore the potential for disaster in our present environmental crisis. But we would be equally foolish to ignore the potentials for constructive change." Me Innis (1975) The interaction between man and the environment has been of vital importance since earliest times as God said in Genesis (1: 26) " ... let us make a man someone like ourselves, to be the master of all life , A phenomenal development took place in the human-environment relationship due to this mastering by man and the easy access to the earth's natural resources. A highly industrialised world arose and gave way to the abuse of these resources that paved the way for the present environmental crisis. The Republic of South Africa is a unique country with unique problems. Due to the previous political dispensation the developed and developing sectors of the country had tragic implications on the environment. The previous government's attitude toward the environment caused a close protectionism and conservation action and this estranged the majority of South Africans from it. The solution to the environmental crisis will prove to be a systematic ecological view- that of sustainability. The Constitution of the Republic of South Africa (1996) provides for the right of every citizen to have access to a healthy environment. The government supports Agenda 21 of the Earth Summit Conference (1992) which suggests that Environmental Education be incorporated in all facets of Education and Training which will ensure sustainability for the present an future generations. The government's Reconstruction and Development Programme (1994) which suggests that programmes be developed to generate an environmental awareness in the youth reflect this concern. The White Paper on Education and Training (1995) state amongst other aspects, that Environmental Education assist in developing environmentally literate citizens with a sustainable lifestyle. This must be done by an interdisciplinary, integrated and active approach to the learning process. At present, South Africa is in a transformation process, which affects all spheres of life, and this includes education and training. A curriculum based on outcomes (Curriculum 2005) is being phased into the South African education system where emphasis is placed on the learners obtaining knowledge, skills, attitudes and values. Without concerted efforts at life-long education for sustainability, South Africa will not be able to become a competitive power in the world, but will face problems with regard to the sustainable use of natural resources, and this can be to the detriment to ensure sustainability for future generations. With Environmental Education as a relatively new and reasonably unknown discipline in the formal sector of an outcomes based curriculum, there are no sufficient models or exemplars, which could be referred to at with the implementation of Environmental Education. The aim of this study is to generate a model through a qualitative, descriptive, contextual and theory generating study, which will realise Environmental Education as a scientific discipline in an outcomes based education dispensation in the Republic of South Africa. The purpose of the model is to act as a reference framework for all facets of curriculisation as well as the teaching of Environmental Education in the new curriculum (Curriculum 2005) to develop environmental literate citizens, which will ensure sustainability for present and future generations.

<p> Schistosomiasis control in sub-Saharan Africa is enacted primarily through mass drug administration, where predictive modeling plays an important role in filling knowledge gaps in the distribution of disease burden. Remote sensing (RS) satellite imagery is used to predictively model infectious disease transmission in schistosomiasis, since transmission requires environmental conditions to sustain specific freshwater snail species. Surveys are commonly used to obtain health outcome data, and while they provide accurate estimates of disease in a specific time and place, the resources required make performing surveys at large spatiotemporal scales impractical. Ongoing national surveillance data in the form of reported counts from health centers is conceptually better suited to utilizing the full spatiotemporal capabilities of publically available RS data, as most open source satellite products can be utilized as global continuous surfaces with historical (in some cases 40-year) timespans. In addition RS data is often in the public domain and takes at most a few days to order. Therefore, the use of surveillance data as an initial descriptive approach of mapping areas of high disease prevalence (often with large focal variation present) could then be followed up with more resource intensive methods such as health surveys paired with commercial, high spatial resolution imagery. Utilization of datasets and technologies more cost effectively would lead to sustainable control, a precursor to eradication (Rollinson et al. 2013). </p><p> In this study, environmental parameters were chosen for their historical use as proxies for climate. They were used as predictors and as inputs to a novel climate classification technique. This allowed for qualitative and quantitative analysis of broad climatic trends, and were regressed on 8 years of Ghanaian national surveillance health data. Mixed effect modeling was used to assess the relationship between reported disease counts and remote sensing data over space and time. A downward trend was observed in the reported disease rates (~1% per month). Seasonality was present, with two peaks (March and September) in the north of the country, a single peak (July) in the middle of the country, and lows consistently observed in December/January. Trend and seasonal patterns of the environmental variables and their associations with reported incidence varied across the defined climate zones. Environmental predictors explained little of the variance and did not improve model fit significantly, unlike district level effects which explained most of the variance. Use of climate zones showed potential and should be explored further. Overall, surveillance of neglected tropical diseases in low-income countries often suffers from incomplete records or missing observations. However, with systematic improvements, these data could potentially offer opportunities to more comprehensively analyze disease patterns by combining wide geographic coverage and varying levels of spatial and temporal aggregation. The approach can serve as a decision support tool and offers the potential for use with other climate-sensitive diseases in low-income settings.</p><p>

Sediment contamination poses a significant problem within aquatic systems. Metals as a pollutant are a major concern because of their toxicity, persistence and non-degradable nature. This study measured sediment metal concentrations within Louisianas coastal estuaries and offshore shoaling regions over a three year period. This was done to determine current concentrations, examine the relationships of physico-chemical, spatial and temporal variables with the metals and compare the metal concentrations to established Sediment Quality Values (SQVs). Variables and physico-chemical parameters were run in a comprehensive statistical model to determine variable contribution to the variation of each metal concentration. Moisture content and organic matter were the two physico-chemical variables that were significant among most of the metals within the study. Spatial variables were also found to be significant, with inshore transects having higher concentrations for most metals with the exception of Cd, which was higher offshore. More specifically the highest concentrations occurred at the Atchafalaya and Breton Sound transects for most metals. There were two temporal variables, year and season. Concentrations decreased for five metals and increased for three over the three year period of this study. Both the summer and fall seasons had higher concentrations than the spring season within the season variable. Lastly, metal concentrations between locations that were oiled and those that were non-oiled during the Deepwater Horizon oil spill were compared. Cobalt had statistically higher concentrations at locations allocated oiled, while Cu had higher concentrations at locations labeled non-oiled. Most metal concentrations in this study were below their respective SQVs, which are used by federal agencies to screen sediments for toxicity. xii Knowing the influence environmental, spatial and temporal variables have on metal concentrations is useful in the assessment of sediment quality specifically when environmental disasters, such as hurricanes or oil spills, repeatedly occur. Determining if the levels of metals have toxic effects on aquatic systems, organisms and humans is a critical first step. This study, the first comprehensive assessment of metals in Mississippi River estuarine sediments, has contributed to developing effective management strategies to control sediment pollution in coastal Louisiana and deltaic systems worldwide.

Photooxidation of isoprene has a large influence on the oxidation capacity of the atmosphere and is a significant source of secondary organic material (SOM) of atmospheric particles. A quantitative understanding of isoprene photooxidation mechanism, in particular in the clean atmosphere, is important but challenging. This thesis presents laboratory and field studies of isoprene photooxidation via the hydroperoxyl (HO2) pathway, believed to be the most important reaction pathway of isoprene-derived peroxy radicals under clean conditions, by using a switchable-reagent-ion (NO+; H3O+) time-of-flight mass spectrometer (SRI-TOF-MS). Isoprene photooxidation via the HO2 pathway was investigated in a continuous-flow chamber. Production yields of methyl vinyl ketone (MVK) and methacrolein (MACR) pathway were determined as (3.8 ± 1.3)% and (2.5 ± 0.9)%, respectively, at <2% RH at 25 oC. Production of MVK and MACR via the HO2 pathway implies concomitant production of hydroxyl ((6.3± 2.1)%) and hydroperoxyl ((6.3± 2.1)%) radicals. The experiments also revealed an unexpected instrument bias that isoprene-derived hydroperoxides (ISOPOOH), the major isoprene oxidation products via the HO2 pathway, were detected as the same product ions as the MVK and MACR. This finding implies that scientific conclusions based on previous ambient measurements of MVK and MACR under clean conditions using similar techniques need to be revisited. As a follow-up study, preliminary analysis of the ambient measurements in the Amazon Basin showed that ISOPOOH isomers contributed to (36±15)% of the total concentration of MVK, MACR, and ISOPOOH isomers under clean conditions. The value is useful for re-evaluation of previous measurements and also defines range of possible anthropogenic influence on isoprene chemistry in the region. SOM production from isoprene photooxidation via the HO2 pathway was also investigated. Isoprene photooxidation was separated from SOM production by using two continuous-flow reactors connected in series and operated at steady state. Relative importance of various intermediates was directly compared from the drop of their gas-phase signals. Isoprene epoxydiols (IEPOX) had a much larger contribution to SOM production than other previously suggested isoprene SOM precursor, ISOPOOH isomers and isoprene, for a wide range of aciddity The IEPOX contribution to isoprene SOM production was further quantified. IEPOX isomers lost from the gas phase accounted for (46 ±11)% of the produced SOM mass concentration. The IEPOX isomers comprised (59±21)% (molecular count) of the loss of monitored gas-phase species. The implication is that for the investigated reaction conditions IEPOX pathway accounted for half of the SOM mass concentration.