Soil nutrient availability is a key component to understanding the boreal ecosystems, as it directly relates to plant productivity and ecosystem diversity. There is however little known about how the nutrient availability changes seasonally in the boreal forest. This study aimed to understand how soil temperature and nutrient availability changed seasonally as well as with or without reindeer grazing. This was done through measuring NH4, NO3, PO4, total N, and C:N ratio in soil samples taken in- and outside a reindeer exclosure in northern Sweden and then analyzing for differences over sampling time, grazing treatment, and the interaction of both. Differences in soil temperature were more extreme in the grazed areas, giving higher summer temperatures and lower winter temperatures, due to a decreased layer of insulating lichens. Increased soil temperatures also resulted in lowering the C:N ratio, possibly by enhancing the microbial activity leading to larger amounts of CO2 being released. No nutrients differed by grazing treatments, possibly due to the system being complex enough to contain contradicting effects. No systematical differences in seasonal nutrient levels could be found, which was deemed as surprising, but opens for the possibility of sampling one time being sufficient to have an approximation of nutrient levels all year round

Eutrophication of reservoir systems, which causes deterioration of water quality through increased algal growth, is detrimental to our sustainable water supply and additionally impairs other beneficial reservoir uses. Limiting the amount of phosphorus (P) entering the system has been the key management tool for this problem, as P is the main limiting nutrient for plant and algal growth. These efforts have focused on controlling input of P from point sources, such as effluents from wastewater treatment plants, dairies, and industrial factories. Even in systems (such as reservoirs) with significantly reduced external P loading, however, there has been continued eutrophication and slower than expected recovery of reservoirs in water quality restoration projects. Other nutrient sources have been studied to explain this phenomenon. The continual eutrophication has been potentially attributed to availability of nutrients from deposited sediments. This is referred to as nutrient recycling, as nutrients previously trapped within sediments may become available within the water column. Deer Creek Reservoir (DCR), a significant water supply in Utah, has had greatly improved water quality after reduction of external P loading. However, there are still large algal blooms at times as well as other water quality issues without clearly attributable causes. Part of the explanation might lie within the deposited sediments, which are present both on the sediment delta and within the reservoir. This thesis provides data that can help researchers understand what role sediment has in the continuation of water quality problems at DCR. Sediment samples were taken across the delta to define both the spatial extent and distribution of P and chemical form, or ‘pool’, of the P. The pools can be used to estimate the ability of the sediment-bound P to move into the water column under various conditions. Results reported here indicate that significant amounts of P are found within these sediments, though not all of it can easily become available for algal growth. We characterized P distribution by taking 91 samples on 6 transects across the exposed delta. Transects were separated by 200 m and samples were taken eery 100 m along the transects. The samples were all analyzed for water soluble P content, and 19 samples were additionally characterized for KCl-, NaOH-, HCl-, and organic (by digestion) P fractions. Total P was determined for these as well by summation. The data showed that water soluble P ranged from 2.28E-03 and 9.81E-03 mg P g−1 dry sediment and showed a decreasing trend along the reservoir. KCl-P ranged from 2.53E-03 and 1.10E-02, NaOH-P from 5.30E-02 to 4.60E-01, HCl-P from 1.28E-01 and 1.34E+00, and organic (residual) P from 8.23E-01 to 3.23E+00 mg·g−1.

Florida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean Water Act (CWA) in 1972 which set the framework for the water quality standards for the entire United States. As a result of the CWA many point sources were eliminated, but in the process it became apparent that nonpoint source loads represented even more of a threat. To further study the physical and chemical characteristics of urban runoff the Nationwide Urban Runoff Program (NURP) was established in 1978. This research lead to a series of management options, named Best Management Practices (BMPs) which proposed various structural and non-structural methods to reduce nutrient loads. But the research and data collection on the effectiveness of these systems to remove nutrients is in its infancy. The main objective of this study was to generate accurate and effective water quality and water quantity data that future stormwater management decisions can be based upon. More specific, this study established automatic monitoring sites throughout the City of Kissimmee, Florida to determine the pollutant loadings into the tributaries of Lake Tohopekaliga. These monitoring sites are located such that inflows from outside the city limits can be isolated and external pollutant loads quantified. Also, additional internal monitoring sites were established to determine the pollutant loads of internal sections of the city. Data from these internal monitoring sites will also be used to determine the variable pollutant removal efficiencies and hydraulic fluctuations of natural, irregular riverine systems. The secondary objective of this study was to perform a pilot study using the discrete grab samples in tandem with the continuous hydraulic and hydrologic data from the monitoring stations. An existing lake within the project limits was chosen for the pilot study area. Monitoring stations are located at the influent and effluent sections of the lake which provided data on the hydraulic and hydrologic parameters. The pilot study determined the nutrient loads to and from the lake and checked for any seasonal variations in pollutant loading or removal efficiencies. For the purpose of this pilot study, only total nitrogen and total phosphorous were examined for two monitoring sites. The nutrient removal efficiency was performed using both the event mean concentration method and the summation of loads method to check for seasonal variation. There were no storm event concentrations available for used in this analysis, however, there were 25 discrete grab samples collected on a bi-monthly basis over a twelve month period. This data was used with corresponding five-minute rainfall and flow data from both the inflow and outflow points. The results of this study did not reveal any seasonal variation in the nutrient concentrations either flowing into or out from the lake. Although there were some relatively lower values in late spring, the concentration levels of total nitrogen did not seem to vary significantly from its mean value of 0.90 mg/l throughout the year. The concentration levels of total phosphorus did range from 0.02 mg/l to 0.48 mg/l, but not in relation to either season or flow volume fluctuations. The lake showed no net removals of total nitrogen and was actually found to be releasing total phosphorus to the downstream receiving waters. The findings of this study are limited due to the fact that the period of pilot study was only for twelve months and there were no rainfall events used in the analysis. Rainfall events are typically high sources of nutrient loads to a lake. The lower efficiencies were probably due to missing the actual higher nutrient load concentrations during the rainfall event. However, even considering the lack of event data, the nutrient removal efficiency for the pond was still low. This analysis did serve well as a basis for performing future analysis once additional data, including rainfall events, has been collected.

While treating domestic wastewater, algae can be grown and harvested for biofuel production. Water is a vital resource and it is imperative to conserve and reuse as much as possible. Several pilot and lab scale experiments were conducted to further research into a full scale wastewater treatment and biofuel production facility. This thesis will include these topics: nitrogen and phosphorus concentrations of clarified wastewater pond feed, nitrogen and phosphorus transformations by algae, and the potential of algae cell disruption technologies to increase nutrient solubilization. The pilot scale experiments were conducted using nine 33 m2, 0.3 m deep multi-culture raceway algae ponds being continuously mixed. These ponds were setup in triplicates and fed municipal wastewater in the form of primary clarifier effluent. The three experiments conducted using these pilot scale ponds were: grab and 24-hour composite influent comparison, nitrogen and phosphorus of various hydraulic residence times (HRTs), and nitrogen and phosphorus nutrient depletion with water recycle. The grab and 24-hour composite comparison was conducted from July 30 to December 3, 2014 and compared the dissolved reactive phosphorus (DRP) and total ammonia nitrogen (TAN) concentrations of the two sample types. Equations were made to convert from grab to 24-hour concentrations. The sample types for both DRP and TAN were on average within 10% and essentially the same. A comparison of data from ponds operating at different HRTs was collected from October 30 and November 6, 2013 and October 29 and November 5, 2014. There were linear correlations between different HRTs and both soluble nitrogen and DRP. Equations were made to calculate the expected removal of ponds using the HRT. The nutrient depletion with water recycle experiment was conducted during October 15-29, 2015. Soluble nitrogen removal was linear with a rate of 1.5 mg-N/L-day and required 14 days to drop below 5 mg-N/L in the ponds. DRP removal was also linear with a rate of 0.18 mg-P/L-day. The algae cell disruption solubilization experiments were conducted using homogenization, sonication, autoclaving, and boiling pretreatment technologies. Algae harvested from the pilot ponds was anaerobically digested and then aerobically digested in an attempt to reuse nutrients for continued growth. It was found that there was no significant difference between the pretreated and non-pretreated digested samples. Keywords: algae, raceway pond, nutrient transformation, anaerobic digestion, aerobic digestion, assimilation, volatilization, nitrogen, phosphorus, pretreatment of algae, nutrient resolubilization, nutrient solubilization

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Autotrophs and heterotrophs differ in their demand, acquisition and use of materials, but fundamentally nutrient demand is inherently linked to metabolism based on the stoichiometry of biochemical reactions. The differences between these two groups of organisms confound straightforward regression approaches to quantifying the relationship between nutrient demand and metabolism at an ecosystem level. We address how nutrient demand in headwater streams changes with shifts in organic matter supply and associated microbial activity by investigating these relationships in the predominantly heterotrophic conditions of a southern Appalachian stream. We measured litter input, organic matter standing crops, litter respiration rates and nitrate demand several times during the course of decomposition. There was a strong relationship between leaf standing crop and nitrate uptake efficiency across dates with maximal efficiency occurring when litter standing crops were highest. There was also an increase in nitrogen (N) uptake rate relative to respiration rates as breakdown progressed, which appears to be due to a shift in nutrient supply from the substrate to the water column associated with the depletion of labile, high quality organic matter in the substrate. It is our contention that streams establish a gradient of resource supply from particulate to dissolved sources that coincides with the movement of materials from terrestrial to marine systems. / Master of Science

Phosphorus (P) is a nutrient of concern in the Chesapeake Bay watershed due to nutrient imbalances in areas with confined animal feeding operations. By converting poultry litter to an ash via thermal conversion, nutrients are concentrated and are economical to ship out of nutrient surplus watersheds to nutrient deficient regions, such as the corn-belt. We initiated incubation and field studies on sandy loam soils to test P and potassium (K) availability from poultry litter ash (PLA). Four PLA products, derived from different sources using different combustion techniques, and 2 biochar products were characterized. Poultry litter (PL) co-products were compared to a no-fertilizer control and inorganic P (triple super phosphate; TSP) and inorganic K (muriate of potash; KCl) fertilizer at similar rates. In the incubation study, standard fertilizers (TSP and PL) had the greatest initial availability for P (55.50% TSP; 9.13% PL) and K (97.99% PL), respectively. The PL co-products varied in availabilities based on thermo-conversion system from 1.60- 8.63% for P to 8.14- 88.10% for K. One ash co-product (ASH4) produced similar availabilities to the industry standard fertilizers after 56 days. In conclusion, co-products from combustion thermo-conversion systems were found be superior to gasification and pyrolysis systems when the desire was to produce the most plant available P and K dense PL co-products. In the field studies, yield, Mehlich-I extractable soil nutrients, plant tissue and grain samples, and organic matter content was used to compare treatments. Poultry litter ash co-products were highly variable due to the thermo-conversion system and feedstock of formation. If all ideal combustion criteria are met, then PL co-products are feasible to use as fertilizer sources, but will need to be individually analyzed for nutrient content before making application recommendations. A greater amount of the co-products will have to be applied to meet the same nutrient availability of the standards due to their lower availability. Fresh PL tends to be the better fertilizer due to its added N content, which is lost in thermo-conversion systems and would have to be supplemented with the ash co-products. Biochars tend to be less available than their ash counter parts. More research using the water soluble availabilities instead of the total concentration nutrients of the co-products are needed to be able to identify stronger relationships with standard fertilizers. / Master of Science