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Upcycling Dairy Manure Fine Solids Captured By Dissolved Air Flotation As Part Of A Phosphorus Recovery And Reuse Strategy, Katherine Keith Porterfield

Graduate College Dissertations and Theses

Dissolved air flotation (DAF) has shown potential to substantially improve phosphorus (P) mass balance on dairy farms by capturing P associated with fine solids from liquid manure, enabling new management options. However, at < 25% total solids, further dewatering and other upcycling is necessary to facilitate export of recovered fine solids off farm for use in bagged or bulk products. I generated plant foods using DAF-captured dairy manure fine solids thermally dried to 45% total solids blended with other organic residuals. Dry biomass of tomato and marigold seedlings amended with 6% v/v plant food was six-times greater than the unamended control and not significantly different from a market alternative treatment. Because thermal dewatering can be prohibitively costly, I generated a second batch of plant foods using DAF-captured dairy manure fine solids conditioned with 3, 4.5 and 6% (w/w) quicklime or lime kiln dust (LKD) and dewatered using a benchtop press for comparison with thermally dried fine solids. Tomato seedling biomass was similar for thermally dried and LKD plant foods, but quicklime plant foods had no effect compared to the unamended control. Quicklime and LKD conditioned fine solids contained approximately 30 and 10 times less plant-available P than thermally dried fine solids, respectively—likely due to precipitation of Ca-P minerals. These studies indicate that DAF-captured dairy manure fine solids could be upcycled to bagged horticultural products with substantial agronomic value, however sustainable materials drying remains a key challenge to realizing this potential.

Evaluation Of Nitrogen And Phosphorus Removal In Alternative Management Practices For Dairy Farm Production Area Runoff: Bioretention Cells And A Woodchip Bioreactor Treatment System, Jillian Sarazen

Graduate College Dissertations and Theses

Non-point source pollution from agricultural areas can lead to the degradation of downstream water bodies, including eutrophication and harmful algal blooms, due to high concentrations of nitrogen (N) and phosphorus (P) emanating from these areas. One source of agricultural runoff that is often overlooked, originates from agricultural production areas, which have impervious surfaces, such as paved and compacted areas, barnyards, cow paths, and silage bunker storage; these areas generate stormwater runoff and contribute to pollution during storm events.

This research evaluates two built stormwater runoff treatment systems designed to treat high concentrations of nutrients in runoff from a dairy farm. …

Nutrient Removal Performance Of A Wood Chip Bioreactor Treatment System Receiving Silage Bunker Runoff, Deborah Joy Kraft

Graduate College Dissertations and Theses

Silage bunker runoff is a form of agricultural pollution that contributes to aquatic ecosystem degradation. Current handling and treatment methods for this process wastewater are often ineffective or expensive. A woodchip bioreactor is an emerging treatment technology designed to facilitate denitrification through the provision of an anaerobic, carbon rich environment. A wood chip bioreactor treatment system, consisting of three pre-treatment tanks, two wood chip bioreactors, and one infiltration basin, was constructed at the Miller Research Complex in South Burlington, Vermont in 2016. Runoff and leachate from an adjacent silage storage bunker is directed into the system. The pre-treatment tanks include …

Phosphorus Uptake In Emergent Macrophytes: An Evaluation Of Vermont-Native Wetland Plant Suitability For Floating Treatment Wetland Applications In Urban Stormwater Settings, Kelly Westhelle

UVM Patrick Leahy Honors College Senior Theses

The USEPA’s revised total maximum daily load (TMDL) for Lake Champlain has Vermont scientists and legislators seeking effective means for curbing phosphorus loads in the Lake Champlain Basin. Developed lands are a critical nonpoint source for phosphorus loading, and green stormwater infrastructure (GSI) ecologically and effectively slow and/or capture nutrients and other pollutants characteristic of urban stormwater runoff. Floating treatment wetlands (FTWs), buoyant mats fitted with wetland plants, are an inexpensive and effective option for improving the water quality of runoff. In urban settings, FTWs are frequently applied to wet stormwater ponds as retrofits. While there are studies demonstrating the …