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

O presente trabalho teve como objetivo estudar a viabilidade da utilização de cinzas de resíduos agroindustriais (bagaço de cana-de-açúcar, cama de frango e casca de arroz) como aditivos minerais substitutos ao cimento Portland, na produção de compósitos fibrosos e concreto leve. As cinzas foram obtidas através da queima e moagem controlada dos resíduos, e tiveram suas características químicas e físicas analisadas. Além do \"compósito referência\" (0% de substituição), os compósitos fibrosos foram produzidos com teores de substituição de cimento Portland de 10%, 15% e 20%, e os concretos leves foram produzidos com 10% de substituição. Foram realizados ensaios físicos e mecânicos nos compósitos fibrosos e concreto leve. Os resultados mostraram que as cinzas de casca de arroz apresentaram propriedades pozolânicas e que podem ser empregadas para a produção dos compósitos fibrosos e concretos leve. No estudo com compósitos fibrosos, os resultados físicos e mecânicos em sua maioria indicaram que a cinza de casca de arroz apresentou os melhores resultados. Como não apresentaram propriedades pozolânicas, as cinzas de bagaço de cana-de-açúcar e cama de frango, mesmo apresentando bons resultados, podem ser utilizadas como \"micro-fillers\". No estudo com concreto leve, a cinza de casca de arroz também se apresentou como melhor substituto para o cimento Portland por apresentar os melhores resultados nos ensaios realizados. / This research examines the viability of the use of waste agro industrials ashes (sugar cane bagasse, poultry litter and rice husk) and mineral additives substitutes to Portland cement in the production of composite fiber and lightweight concrete. The ashes were obtained through controlled burns and milling waste, and had their chemical and physical characteristics analyzed. Besides the \"composite reference\" (0% substitution), the fiber composites were produced with levels of replacement of Portland cement, 10%, 15% and 20%, and lightweight concrete were produced with 10% of replacement. Were tested on physical and mechanical fiber composites and lightweight concrete. The results showed that the ashes of rice husk had pozolanic properties and can be used for the production of fiber composite and lightweight concrete. In the study with fiber composites, the results physical and mechanical mostly indicated that the rice husk ash showed the best results. As there had pozolanics properties, the ashes of sugar cane bagasse and poultry litter, even showing good results, can be used as \"micro-fillers\". In the study with lightweight concrete, the ash of rice husk is also presented as a better replacement for Portland cement by presenting the best results in tests.

O presente trabalho teve como objetivo estudar a viabilidade da utilização de cinzas de resíduos agroindustriais (bagaço de cana-de-açúcar, cama de frango e casca de arroz) como aditivos minerais substitutos ao cimento Portland, na produção de compósitos fibrosos e concreto leve. As cinzas foram obtidas através da queima e moagem controlada dos resíduos, e tiveram suas características químicas e físicas analisadas. Além do \"compósito referência\" (0% de substituição), os compósitos fibrosos foram produzidos com teores de substituição de cimento Portland de 10%, 15% e 20%, e os concretos leves foram produzidos com 10% de substituição. Foram realizados ensaios físicos e mecânicos nos compósitos fibrosos e concreto leve. Os resultados mostraram que as cinzas de casca de arroz apresentaram propriedades pozolânicas e que podem ser empregadas para a produção dos compósitos fibrosos e concretos leve. No estudo com compósitos fibrosos, os resultados físicos e mecânicos em sua maioria indicaram que a cinza de casca de arroz apresentou os melhores resultados. Como não apresentaram propriedades pozolânicas, as cinzas de bagaço de cana-de-açúcar e cama de frango, mesmo apresentando bons resultados, podem ser utilizadas como \"micro-fillers\". No estudo com concreto leve, a cinza de casca de arroz também se apresentou como melhor substituto para o cimento Portland por apresentar os melhores resultados nos ensaios realizados. / This research examines the viability of the use of waste agro industrials ashes (sugar cane bagasse, poultry litter and rice husk) and mineral additives substitutes to Portland cement in the production of composite fiber and lightweight concrete. The ashes were obtained through controlled burns and milling waste, and had their chemical and physical characteristics analyzed. Besides the \"composite reference\" (0% substitution), the fiber composites were produced with levels of replacement of Portland cement, 10%, 15% and 20%, and lightweight concrete were produced with 10% of replacement. Were tested on physical and mechanical fiber composites and lightweight concrete. The results showed that the ashes of rice husk had pozolanic properties and can be used for the production of fiber composite and lightweight concrete. In the study with fiber composites, the results physical and mechanical mostly indicated that the rice husk ash showed the best results. As there had pozolanics properties, the ashes of sugar cane bagasse and poultry litter, even showing good results, can be used as \"micro-fillers\". In the study with lightweight concrete, the ash of rice husk is also presented as a better replacement for Portland cement by presenting the best results in tests.

Poultry litter ash (PLA) is a co-product from manure-to-energy systems that originated in response to increased poultry litter (PL) volumes generated in concentrated poultry production regions. Investigating PLA as a crop fertilizer is an alternative solution to balancing poultry and crop regional nutrient cycling in the Commonwealth of Virginia. As the expanding world population places pressure on the poultry industry to meet consumption demands, increased PL production presents an obstacle to identify alternative uses for increased volumes. Currently, Virginia produces 44 million broilers with PL produced predominately in the Shenandoah Valley and Eastern Shore. Likewise, a growing world population places pressure on crop production areas and subsequently finite natural resources used for crop fertilization. Poultry litter ash is an alternative phosphorus (P) and potassium (K) source enhancing transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source when compared to PL. Three PLA products [(fluidized bed bulk (FB Bulk), fluidized bed fly (FB Fly), and combustion Mix (CMix)], two manufactured co-products [(granulated poultry litter ash (GPLA), and ash coated urea (ACU)] were evaluated as P, K, and N sources for corn (Zea Mays L.) production in comparison to industry fertilizers [(PL, triple superphosphate (TSP), muriate of potash (KCL), and urea). A comprehensive examination of elemental composition, P speciation, P and K solubility, improved functionality into granulized forms, and field testing were conducted to discern PLA potential as an alternative fertilizer source. Poultry litter ash products were evaluated by total elemental analysis, backscatter-electron dispersive (BSED) microscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Poultry litter ash elemental concentrations were highly variable ranging from 50.6 to 102.0 g P kg -1 and 62.6 to 120.0 g K kg -1 and were comparatively higher than PL concentrations. Phosphorus structures that provided and controlled P solubility were Ca and Ca-Mg-phosphate compounds. Spectroscopy confirmed Ca structures as predominately monetite (dicalcium phosphate anhydrous; CaHPO4; log K ̊ 0.30) and brushite (dicalcium phosphate dihydrate; CaHPO4.2H20; 0.63 log K ̊ ) species that were supported by BSED and elemental stoichiometric ratios (Ca:P; 1.12 to 1.71:1). Additionally, GPLA acidified from FB Fly had higher brushite and monetite percentages described by spectra models, translating into a more soluble Ca-phosphate species when compared to FB Fly original P species. Granulated poultry litter acidulation trials successfully identified a desired granulation point of 29% (14.5 g acid to 50 g PLA) phosphoric acid (75% H3PO4) acidulation. Acidulation dose response relationships created simple linear regression (SLR) equations that sufficiently (R2 > 0.80) described changes in total measurable P and water soluble P, pH, and exothermic reaction temperatures to increasing H3PO4 acidulation. Solubility tests included: sequential extraction, particle size effect on solubility, carbon effect on water soluble P, and Mehlich-1 extraction of PLA sources that confirmed decreased P solubility. A majority PLA P was found in bound plant unavailable fractions (87.7 to 97.7% P of total P). Granulated poultry litter ash had improved P plant available P of 36.0% P of total P. Carbon (C) effects on PLA P were examined by ashing PLA samples in a muffle furnace at 550 ̊C. Differences in total carbon content negatively impacted FB Bulk and CMix total P (1.30 and 4.56 g P kg -1); however, muffle furnace temperatures increased FB Fly total P by 6.74 g P kg -1. All fertilizer products were investigated under field conditions in separate P, K and N corn studies across Virginia coastal plain soils to determine fertilizer effects on corn plant parameters [(most mature leaf (V6), corn ear leaf (R1), and grain (R6)]. Poultry litter P treatments, averaged over rate, recorded highest yield in both years. At eight of nine field sites, FB Bulk resulted in numerically or significantly higher Mehlich-1 concentrations than other P sources post-harvest. Although Mehlich-1 P increased, yield and plant parameters did not; which leads to the conclusion that PLA sources increased soil residual P that did not translate into immediate plant availability recorded within a growing season. Across plant efficacy parameters examined, PLA K is a comparable nutrient source and improved plant parameters when compared to control. Eighteen out of twenty-one plant parameters examined found similar ACU and urea effects on N concentrations. Therefore, ACU is a comparable N source to urea. When compared to industry fertilizer sources, we concluded that PLA is a slowly available P source, decreased P availability negatively affected early plant growth, K is a comparable nutrient source and improved plant parameters compared to control, and ACU effectively provided N to maintain sufficient corn growth. In conclusion, PLA co-products serve as a densified nutrient source that may provide plant available nutrients if processed to aid in nutrient distribution to grain producing areas. / Doctor of Philosophy / Poultry litter ash (PLA) is a co-product from manure-to-energy systems that originated in response to increased poultry litter (PL) volumes generated in concentrated poultry production regions. Investigating PLA as an alternative crop fertilizer is essential to balancing poultry and crop regional nutrient cycling in the Commonwealth of Virginia. As the expanding world population places pressure on the poultry industry to meet consumption demands, heightened PL production presents an obstacle to identify alternative uses for increased volumes. Currently, Virginia produces 44,683,904 broilers with PL produced predominately in the Shenandoah Valley and Eastern Shore. Likewise, a growing world population places pressure on crop production areas and subsequently finite natural resources used for fertilization vital to maintaining crop yields. Poultry litter ash, a co-product from manure-to-energy systems, is an alternative phosphorus (P) and potassium (K) source enhancing transportation logistics, repurposing PL nutrients, and offers dual purpose as a fertilizer and an energy source when compared to PL. In this dissertation, three PLA products [(fluidized bed bulk (FB Bulk), fluidized bed fly (FB Fly), and combustion Mix (CMix)], two manufactured co-products [(granulated poultry litter ash (GPLA), and ash coated urea (ACU)] were evaluated as P, K, and N source for corn (Zea Mays L.) production in comparison to industry fertilizers (PL, triple superphosphate (TSP), muriate of potash (KCL), and urea). Each of the following chapters provides a comprehensive examination of the following topics: elemental composition, P speciation, P and K solubility, improved functionality into granulized forms, and field testing designed to provide parameters to conclude PLA potential as an alternative P, K and N source. In the second chapter, PLA products were evaluated by total elemental analysis, backscatter-electron dispersive (BSED) microscopy, and X-ray absorption near edge structure (XANES) spectroscopy. Poultry litter ash elemental concentrations are highly variable and are comparatively higher than PL concentrations. Phosphorus structure and species identified Ca as the primary element controlling P structure and subsequent solubility. The third component of this dissertation is granulation trials investigating phosphoric acid effects on granulizing and increasing total and water soluble P. Our results identified 29% (14.5 g acid to 50 g PLA) phosphoric acid acidulation for desired granule size. The third dissertation component examines PLA solubility. The results demonstrated PLA decreased P water solubility when compared to industry fertilizer sources. Granulated poultry litter ash demonstrated improved P plant availability due to the granulation process. The final and fourth dissertation components investigated PLA sources under field conditions in separate P, K and N corn studies across Virginia coastal plain soils to determine fertilizer effects on corn plant parameters. Minority of plant parameters tested revealed P control yielded numerically higher P concentrations than PLA P sources tested. Poultry litter P treatments, averaged over rate, recorded highest yield in both years. At eight of nine field sites, FB Bulk resulted in numerically or significantly higher Mehlich-1 concentrations than other P sources post-harvest. Although Mehlich-1 P concentrations increased, yield and plant parameters did not; which leads to the conclusion that PLA sources increased soil residual P that did not translate into immediate plant availability recorded within a growing season. Across plant efficacy parameters examined, PLA K is a comparable nutrient source and improved plant parameters when compared to controls. The majority of plant parameters examined found similar ACU and urea effects on N concentrations. Therefore, ACU is a comparable N source to urea. When compared to industry fertilizer sources, field results concluded that PLA is a slowly available P source, decreased P availability negatively affected early plant growth, K is a comparable nutrient source and improve plant parameters compared to control, ACU effectively provides N to maintain sufficient corn growth. In conclusion, PLA co-products serve as a densified nutrient source that may provide plant available nutrients if processed to aid in nutrient distribution to grain producing areas.