Advanced oxidation of organic pollutants with TiO2 photocatalysts is limited due to the wide bandgap of TiO2, 3.2 eV, which requires ultraviolet (UV) radiation. When nanosized TiO2 is modified by carbon doping, charge recombination is inhibited and the bandgap is narrowed, allowing for efficient photodegradation under visible light. Here, we propose a flame spray pyrolysis (FSP) technique to create TiO2. The facile process of FSP has been successful in preparing highly crystalline TiO2 nanoparticles. Using the same procedure to deposit TiO2 onto biochar, the photocatalyst was doped by the carbonaceous material. The morphology, crystalline and electronic structure of the FSP TiO2 and TiO2-decorated biochar (TiO2-BC) were characterized by SEM, XRD, TGA, DLS, and diffuse reflectance UV-vis spectroscopy. Photocatalytic performance of TiO2 and TiO2-BC was investigated for model organic contaminants in an aqueous solution under UV and visible light, which will be compared to that of Degussa P25 TiO2 as a control.

Over the past century, the world's rivers have become increasingly impounded to combat water scarcity and fossil-fuel reliance. Large dams have faded from popularity due to their adverse environmental effects, but small ponds and reservoirs continue to be constructed at high rates. Due to limited data regarding their size and flow, it has been difficult to assess how these smaller impoundments impact rivers. This study combined rainfall runoff data from the Chesapeake Bay Model with the unique routing framework of VA Hydro to create a simplistic hydrologic model capable of analyzing impoundment-induced flow alteration. Using standard design techniques and satellite imagery, a methodology was developed to build realistic stage-storage-discharge relationships for small and large impoundments. Eleven impoundments of the Difficult Run watershed were modeled within VA Hydro to assess their cumulative impact on downstream flow. Multiple models were created with different active impoundments and run for the full model period, 1984 - 2005. Flow alteration increased significantly with additional impoundments. Peak flows were attenuated as water was stored behind outlets, but median flows were increased as this water was slowly released. Average storm duration increased due to extended rising and falling limbs caused by impoundment outlets. Headwater channels increasingly ran dry, decreasing extreme low flows due to impoundment evaporation. Large reservoirs had a greater impact on median flows, but smaller ponds dominated low flow alteration. These results suggest that traditional hydrologic assumptions and metrics may be incapable of analyzing a changing flow regime without explicitly considering small and large impoundments upstream. / Master of Science / At first look, dams are an excellent solution to water scarcity and energy independence. They trap clean water and direct it through turbines. Unfortunately, their installation and operation creates many negative environmental impacts by fundamentally altering downstream channels, leading to a loss of fish vitality and river function. Large dam construction has decreased in the US because of these effects, but small dams continue to be built at high rates due to growing agricultural and stormwater demands. Their impact on rivers is less understood due to limited data availability regarding their size and function. This experiment used standard design techniques and widely available satellite data to create a representative model for dams of all size. Multiple tests were run, progressively increasing the number of dams within a watershed and analyzing their impact on downstream flow. With increased impoundment, high floods decreased in magnitude. However, more-typical medium flows increased. River flow became more static, with less extreme floods and more medium flows. The modeled dams greatly decreased drought flows as trapped water evaporated and decreased outflow. This impact was particularly noticeable in ponds that drained only a small area as they took longer to refill after drying. Larger dams more greatly impacted medium flows. These results contribute significantly to water availability prediction by more realistically representing dam processes. Although more work is needed to refine the impoundment modeling strategy, this study has effectively demonstrated that small and large dams affect flow in different manners and need to be accounted for accordingly.

Lake Eola is an eutrophic, land-locked lake located in downtown Orlando, Florida. It has a surface area of approximately 27 acres (11 .0 Ha) and a maximum water depth of 22 feet (6.7 meters) near the center. Sediment samples were collected from the lake bottom at various water depths and analyzed for physical characteristics and phosphorus content. Lake water samples were collected and analyzed for selected parameters as related to sediment phosphorus dynamics. Phosphorus release from agitated, aerobic sediment samples was measured in laboratory batch experiments. Phosphorus release from anaerobic hypolimnetic sediments was measured by utilizing~ situ isolation chambers. Results indicate that phosphorus release from anaerobic Lake Eola sediments can be described by the Freundlich isotherm, indicating that release may be a desorption process. Phosphorus budget calculations indicate that the phosphorus that accumulates in the hypolimnion of Lake Eola has the potential for increasing productivity when overturn occurs.

No description available.

No description available.

No description available.

No description available.

Water is one of, if not the most, valued natural resource on the planet. Over the years, the quality of Earth's waters has deteriorated primarily due to pollution. All ecosystems are highly dependent on this resource, which makes it very important to protect water from unnecessary pollution. One ecosystem that has been greatly affected by pollution, mainly as a result from runoff of fertilizers used by farmers in the region, has been the Everglades located in south Florida. As a result, the protection and desire to restore this ecosystem has become the subject for litigation in recent years. The Miccosukee Tribe of Indians is the chief litigant for the pursuit for improved water quality due to their dependence on the water of the Everglades for survival. This thesis will examine the Everglades in its entirety by providing a history of the establishment of the Everglades as well as a description of the Everglades ecosystem and the water quality. The thesis will then introduce the Miccosukee Tribe of Indians and how they have become dependent on the Everglades ecosystem. Finally, the thesis will examine the involvement of the state and federal government in the issue of water quality through various agencies and pieces of legislation. The purpose of this thesis is to then analyze several cases in which the Miccosukee Tribe has been an interested party and sought to achieve improvements for the water quality of the Everglades. In addition to the original cases, the thesis will provide subsequent case history through its most current status. The thesis will explain whether the Miccosukee Tribe has been successful in its attempt to provide strict standards for water quality and hold those in violation of these standards responsible for their actions.

京都大学 / 新制・課程博士 / 博士(地球環境学) / 甲第24953号 / 地環博第244号 / 新制||地環||48(附属図書館) / 京都大学大学院地球環境学舎地球環境学専攻 / (主査)教授 西前 出, 准教授 淺野 悟史, 教授 小林 広英 / 学位規則第4条第1項該当 / Doctor of Global Environmental Studies / Kyoto University / DGAM

The Mississippi Department of Wildlife, Fisheries and Parks currently manages 18 State Lakes and 17 State Park Lakes to provide public fishing opportunities. My goal was to conduct a comprehensive analysis of monitoring and management activities in State Lakes to enhance understanding of lake dynamics, further develop existing management initiatives, and identify alternative avenues for effective management. To achieve this objective, I have undertaken a comprehensive examination and synthesis of the historical background pertaining to State Lakes and conducted an analysis of pertinent data regarding lake characteristics such as the physical and chemical attributes of the lakes, the features of their respective watersheds, the composition of fish communities, and the angler use they receive. Based on my analysis, it is evident that these lakes possess distinct and diverse attributes that may be effectively managed to cultivate a wide range of fisheries that are well-suited to the numerous regions within Mississippi.