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Turbidity is an important measurement of water quality, considering it describes water clarity and is an indirect indicator of light transmittance in the water column. Turbidity may impact fish that rely on vision to forage by affecting ability to search for prey. Largemouth bass (LMB; Micropterus salmoides) is a visual predator that may have lower foraging success resulting in reduced growth, reproduction, or survival under conditions of high turbidity. I conducted a field experiment in Wolf Lake, Mississippi to assess impacts of turbidity on diet and distribution and a laboratory experiment with manipulated turbidity levels (0 – 250 NTU) to assess foraging efficiency of LMB. There were no significant relationships between turbidity and diet or distribution in the field study. However, there were significant effects of turbidity on foraging efficiency in laboratory trials. These results indicate that assessing turbidity is important to manage LMB in systems susceptible to high turbidity levels.

Silt fence is one of the most widely used perimeter control devices and is considered an industry standard for use in the control of sediment transport from construction sites. Numerous research studies have been conducted on the use of silt fence as a perimeter control, including a number of studies involving controlled laboratory flume tests and outdoor tests performed in the field on construction sites with actual monitored storm events. In field tests, due to the random and uncontrollable nature of real storm events and field conditions, studies have shown difficulty in evaluating silt fence performance. These field studies have shown the need for performance testing of silt fence in a more controlled environment, which can also simulate the actual use and performance in the field. This research, which is a continuation of ongoing research on silt fence fabrics at UCF Stormwater and Management Academy, was conducted in order to evaluate silt fence performance under simulated field conditions. Presented in this thesis are evaluation of two silt fence fabrics, a woven (ASR 1400) fabric and nonwoven (BSRF) fabric. Both fabrics were installed separately on a tilted test bed filled with a silty-sand soil and subjected to simulated rainfall. Previous field studies on the performance of silt fence fabrics have evaluated the turbidity and sediment removal efficiencies only after the rain event, with the assumption that the efficiency values represent the true overall performance of silt fence. The results of this study revealed that the turbidity and suspended sediment performance efficiencies of silt fence were significantly affected by the time of sampling. The performance efficiencies during rainfall remained less than 55 percent, however, after the rainfall event ended, the performance efficiencies increased over time, reaching performance efficiency upwards of 90 percent. The increase in efficiency after rainfall was due to the constant or decreasing ponding depth behind the silt fence, increased filtration due to fabric clogging, and sedimentation of suspended particles. The nonwoven fabric was found to achieve higher removal efficiencies and flow-through rates both during and after the rain event when compared with the woven fabric. However, over the entire test duration (during and after rainfall combined), the projected overall efficiencies of both fabrics were similar. The projected overall average turbidity performance efficiencies of the woven and nonwoven silt fence fabrics was 80 and 78 percent, respectively. Both fabric types also achieved comparable overall average suspended sediment concentration efficiencies of 79 percent. This result leads to the conclusion that silt fence performance in the field is dependent on three main processes: filtration efficiency occurring during the rain event, filtration and sedimentation efficiency occurring after the rainfall event, and flow-through rate of the silt fence fabrics. Decreases in the flow-through rate lead to increases in the overall efficiency. This thesis quantifies the different mechanisms by which these processes contribute to the overall efficiency of the silt fence system and shows how these processes are affected by different conditions such as the degree of embankment slope and rainfall intensity.

This study evaluated alternative sulfide treatment processes for potable water systems that rely on groundwater supplies. Research for this study was conducted at the Imperial Lakes (IL) and Turner Road (TR) water treatment plants (WTPs) in Polk County, Florida. These WTPs are in the process of refurbishment and expansion, and will require the installation of a new groundwater well. The IL and TR WTPs both rely upon groundwater sources that contain total sulfide at concentrations ranging from 1.4 to 2.6 mg/L. Sulfide is a concern because if left untreated it can impact finished water quality, corrosivity, create undesirable taste and odor, and oxidize to form visible turbidity. For this reason, the raw water will require treatment per Florida Department of Environmental Protection (FDEP) "Sulfide Rule" 62-555.315(5)(a). This rule does not allow the use of conventional tray aeration (currently in use at the IL and TR WTPs) for wells that have significant total sulfide content (0.6 to 3.0 mg/L). This research was commissioned because the potential water treatment method identified in the Sulfide Rule (i.e. forced-draft aeration) would not adequately fit within the confines of the existing sites and would pose undue burden to neighboring residents. In addition, an effective sulfide treatment process was desired that offered a low profile, did not necessitate the need for additional complex chemical feed systems, minimized the extent of electrical infrastructure upgrades, and was inexpensive to construct and operate. To meet these goals, several alternative technologies were evaluated at the desktop and bench-scale; these included anion exchange, various oxidation methods, and alternative media filtration processes. From that effort, several processes were selected for evaluation at the pilot scale: bleach (NaOCl) oxidation preceding electromedia filtration; manganese (IV) oxide (MnO2) filtration continuously regenerated with bleach; and ferrate (Fe(VI)) oxidation. Electromedia and MnO2 filtration were shown to be effective for total sulfide treatment. Both processes reduced total sulfide content to below detection levels ( > 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. The use of bleach oxidation ahead of media filtration also produced finished water with low turbidity ( > 1.0 NTU) as compared to conventional tray aeration and chlorination processes (6-16 NTU, as observed in this study). It was determined that the media filtration approach (electromedia and MnO2) was effective for sulfide treatment and met the County's site objectives established at the outset of the project. Ferrate was also shown to reduce total sulfide content to below detection levels ( > 0.1 mg/L) for groundwater supplies containing as much as 2.6 mg/L of total sulfide. An opinion of probable capital costs for installing a sulfide oxidation/filtration process at either the Imperial Lakes or Turner Road WTP was estimated to range from roughly $830,000 to $1,100,000. That equates to a $/kgal capital cost of $0.10 to $0.32 (at 8% for 20 years). An opinion of annual probable bleach chemical costs was estimated to range from $3,500 to $9,800 for the IL WTP and $3,500 to $5,800 for the TR WTP.

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<p>The World Health Organization reports 9% of the world’s population lack access to an improved drinking water source. Safe drinking water is a major global challenge, especially in rural areas where according to UNICEF 80% of those without access to improved water systems reside. While water, sanitation, and hygiene (WASH) related diseases and deaths are common outcomes of unsafe water, there is also an economic burden associated with unsafe water. These burdens are most prominent in rural areas in less developed nations. Slow sand filters (SSFs), or biological sand filters (BSF), are ideal water treatment solutions for these low resource regions. SSFs are the oldest municipal drinking water treatment system and improve water quality by removing suspended particles, dissolved organic chemicals, and other contaminants, effectively reducing turbidity and associated taste and odor problems. Removal of turbidity from the water enables the use of low-cost disinfection methods such as chlorination. While the working principles of slow sand filtration remained the same, the design, sizes and application of slow sand filters have been customized over the years. The first chapter of thesis reviews these adaptations and their performance on contaminant removal, and specifically addresses engineering aspects of slow sand filters that are not widely understood, even by those that implement SSFs in the field.</p> <p>The second and third chapters detail an SSF-based water treatment and monitoring system that seeks to provide portable water to rural schools and communities. Piping drinking water to remote rural areas from centralized treatment facilities requires huge capital investments. On the other hand, delivering drinking water by the less expensive point‐of‐use technologies often results in improper operation, and lack of proper documentation on water quality and usage.</p> <p><br></p> <p>The strategy documented in this research for addressing this problem is to produce drinking water at the point-of-use, and then establish and document drinking water quality through cellphone-based monitoring of this water. By doing both (point-of-use treatment and cellphone-based monitoring), we are effectively using to advantage the best of both worlds. Decentralized (point-of-use) water treatment systems can be deployed in rural communities to produce potable water. Integrating a cellphone-enabled colorimeter-turbidity meter (CT meter), developed as part of this research, into the water treatment system will provides water quality data to ensure public health safety. The integrated water system included slow sand filtration, chlorination, and phone-based monitoring (i.e., the CT meter). To establish larger-scale (thousands of schools) feasibility, pilot treatment systems were established in 3 rural schools in Kenya. This pilot network was established through the collaborative efforts of: (i) The research team at Purdue, (ii) MaJi Safi International (MSI), a Purdue related startup based in Eldoret, Kenya, and (iii) several western Kenya Schools.</p> <p><br></p> <p>The second chapter of details the design and testing of the CT meter at Purdue. The third chapter evaluates, through pilot field tests in Kenyan schools, the integrated water treatment and monitoring system for economic and technical viability. The CT meter performance was successful both in the lab and in the field. The water systems that were installed, used daily, and monitored with the CT meter, consistently produced portable water that met the local regulatory drinking water standards.</p>

Deep-marine sandstones containing significant (> 10%) detrital mud (silt and clay) matrix have become increasingly recognized, but mostly in drill core or poorly exposed outcrops where details of their vertical and lateral variability are poorly captured. Exceptional vertical and along-strike exposures of matrix-rich and associated matrix-poor deposits in deep-marine strata of the passive margin Neoproterozoic Windermere Supergroup and foreland basin Ordovician Cloridorme Formation, provide an unparalleled opportunity to document such characteristics. In both study areas, strata form a 100s m long depositional continuum that at its upflow end consists of thick-bedded matrix-poor sandstone (<20% matrix) that transforms progressively downflow to medium- to thick-bedded muddy sandstone (20 – 50% matrix) to medium-bedded bipartite facies with a basal sandy (30 – 60% matrix) part overlain sharply by a muddier part (40 – 80% matrix), and then to thin-bedded sandy mudstone (50 – 90% matrix). This depositional continuum is then overlain everywhere by a thin- to very thin-bedded traction-structured sandstone and/or silty mudstone cap. This consistent lithofacies change is interpreted to reflect particle settling in a rapidly but systematically evolving, negligibly-sheared sand-mud suspension developed along the margins (Windermere) and downflow terminus (Cloridorme) of a high-energy, mud-enriched avulsion jet. Stratigraphically upward, beds of similar lithofacies type succeed one another vertically and transform to the next facies in the depositional continuum at about the same along-strike position, forming stratal units 2–9 beds thick whose grain-size distribution gradually decreases upward. This spatial and temporal regularity is interpreted to be caused by multiple surges of a single, progressively waning turbidity current, with sufficient lag between successive surges for the deposition of a traction-structured sandstone overlain by mudstone cap. Furthermore, the systematic backstepping or side-stepping recognized at the stratal unit scale in both the Windermere and Cloridorme is interpreted to be driven by a combination of knickpoint migration and local topographic steering of the flows, which continued until the supply of mud from local seafloor erosion became exhausted, the main channel avulsed elsewhere, or a new stratal element developed.

Vatten är en livsviktig resurs därför behöver kvalitén övervakas. Slamhalt i vatten är viktigt eftersom det kan föra med sig gifter och näringsämnen, men även grumlar vattnet vilket kan påverka livsmiljön för vattenlevande organismer. Slamhalt varierar över tid på grund av olika processer som transporterar material till vattendrag. För att mäta slamhalten har man historiskt tagit vattenprover i fält. Det är tidsödande och görs sällan vilket leder till att man lätt missar toppar och dalar i flödet.  Turbiditet är möjligt att mäta in situ och innebär att vattnets ljusgenomsläpplighet mäts. Det kan mätas med täta intervall vilket ger detaljerad information om förändringar i vattendragen. Korrelationen mellan turbiditet och slamhalt har undersökts flera gånger men eftersom mätningar reagerar på partiklars storlek och form behöver man utvärdera sambandet för varje enskilt vattendrag.  2017 gjordes en studie för Sveriges lantbruksuniversitet där Hoang (2017) använde multivariabel statistik för att undersöka turbiditet korrelerat med fosfor samt jordarters och markanvändnings påverkan på relationen i svenska vatten.  Sedan dess har markdata uppdaterats vilket gör det aktuellt att undersöka korrelationen mellan slamhalt och turbiditet. Genom linjär regression visades ett tydligt samband mellan turbiditet och slamhalt för många avrinningsområden. De högsta korrelationerna syntes för områden med hög fördelning av åkermark och lerhalt. / Water is a vital resource for life, that is why water quality is monitored. Suspended solids in water are important because it transports pollutants and nutrients, it also dims the water which can affect the environment for water living organisms. Suspended solids change over time due to different processes that transport materials to waterbodies. Historically, suspended solids have been measured by taking samples in the field. That takes a lot of time and fluctuations are lost because of dispersed measuring periods.  Turbidity can be measured in-situ and quantifies the light attenuation of the water. It can be measured with tight intervals which results in detailed information about changes in the waterbody. The correlation between suspended solids and turbidity has been studied several times, however, a turbidity sensor reacts to particle size and form which means that the correlation needs to be investigated for every individual waterbody.  2017 a study at the Swedish university of agriculture was done where Hoang (2017) used multivariate statistics to study turbidity correlated with phosphorus, as well as soil classes and land use factors influence on the relationship in Swedish waters. Since then, new data for soil and land use have been updated which makes it relevant to evaluate the correlation between suspended solids and turbidity. Through linear regression a clear correlation was shown for many catchments. The highest correlations were found in areas with high rates of agriculture and clay rich soils.