Academic literature on the topic 'Aluminium Oxide Phosphate'

Compounds containing the −PO3H2 function, such as monoesters of phosphoric acid and phosphonic acids, specifically bind to aluminium oxide in aqueous solution under experimental conditions where non-phosphorylated compounds are completely desorbed. The bound organic phosphate can be specifically displaced by aqueous solution of inorganic phosphates thus allowing their separation or detection by a technique similar to that of affinity chromatography. The consequences of this finding for phosphate compound biochemistry are discussed.

Phosphorus availability is a major limiting for crop production. Bacterial solubilization of insoluble inorganic phosphate has been studied as a means of providing available phosphorus for crop production. Bacterial abilities to solubilize calcium phosphate and rock phosphate have been identified to be related with their abilities to produce gluconic acid and ketogluconic acid. However, there is no information regarding the relationship between bacterial ability to solubilize aluminum phosphate and their ability to produce organic acids. This study was conducted to investigate the relationship between bacterial ability to solubilize calcium and aluminum phosphates with their ability to produce organic acids. Bacterial ability to solubilize calcium and aluminum phosphates were determined as the concentration of soluble phosphate in the filtrate of bacterial cultivation media, while bacterial ability to produce organic acids were assessed from the accumulated organic acids in its. The results showed that bacterial abilities to solubilize calcium and aluminum phosphates well related to their abilities to produce organic acids. Organic acids related with the solubilization of calcium phosphate differ from the ones relatedAlam, S., S. Khalil, N. Ayub, and M. Rashid. 2002. In vitro solubilization of inorganic phosphate by phosphate solubilizing microorganisms (PSM) from maize rhizosphere. Int. J. Agri. Biol. 4: 454-458.Beauchemin, S., D. Hesterberg, J. Chou, M. Beauchemin, R.R. Simard, and D.E. Sayers. 2003. Speciation of phosphorus in phosphorus-enriched agricultural soils using X-ray absorption near-edge structure spectroscopy and chemical fractionation. J. Environ. Qual. 32:1809–1819.Bolan, N.S., R. Naidu, S. Mahimairaja, dan S. Baskaran. 1994. Influence of low-molecular-weight organic acids on the solubilization of phosphates. Biol. Fertil. Soils 18: 311-319.Cline, G.R., P.E. Powell, P.J. Szaniszlo, dan C.P. Reid. 1983. Comparison of the abilities of hydroxamic and other natural organic acids to chelate iron and other ions in soil. Soil Sci. 136: 145-157.Curtin, D., and J.K. Syers, 2001. Lime-induced changes in indices of soil phosphate availability. Soil Sci. Soc. Am. J. 65:147–152.Fox, T.R., N.B. Comerford, dan W.W. McFee. 1990. Phosphorus and aluminium release from a spodic Horizon mediated by organic acids. Soil Sci. Soc. Am. J. 54: 1763-1767.Hue, N.V., G.R. Craddock, dan F. Adams. 1986. Effect of organic acids on aluminium toxicity in subsoils. Soil Sci. Soc. Am. J. 50: 28-34.Johnson, S.E., and R.H. Loeppert. 2006. Role of organic acids in phosphate mobilization from iron oxide. Soil Sci. Soc. Am. J. 70:222–234.Kumari, A., K.K. Kapoor, B.S. Kundu, and R.K. Mehta. 2008. Identification of organic acids produced during rice straw decomposition and their role in rock phosphate solubilization. Plant Soil Environ. 54: 72–77Lopez-Hernandez, D., D. Flores, G. Siegert, dan J.V. Rodriguez. 1979. The effect of some organic anions on phosphate removal from acid and calcareous soils. Soil Sci. 128: 321-326.Lopez-Pineiro, A., dan A. Garcia-Navarro. 2001. Phosphate fractions and availability in Vertisols of South-Western Spain. Soil Sci. 166: 548-556.Olsen, S.R. dan Sommers, L.E. 1982. Phosphorus. In Page, A.L., Miller, R.H. & Keeney, D.R. (eds.). Methods of Soil Analysis. Part 2. 2nd ed. ASA and SSSA Publisher, Madison.Rao, W.V.B.S., and M.K. Sinha. 1963. Phosphate dissolving microorganisms in the soil and rhizosphere. Indian J. agric. Sci. 33: 272-278.Rodriguez, H., T. Gonzalez, I. Goire, dan Y. Bashan. 2004. Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium Azospirillum spp. Naturwissenschaften 91: 552-555.Sagoe, C.I., T. Ando, K. Kouno, and T. Nagaoka. 1997. Effect of organic-acid treatment of phosphate rocks on the phosphorus availability to Italian ryegrass. Soil Sci. Plant Nutr. 43: 1067-1072.Sanchez, P.A. 1976. Properties and Management of Soils in the Tropics. John Wiley & Sons, Inc. New York. 618 pp.Siddique, M.T., and J.S. Robinson. 2003. Phosphorus sorption and availability in soils amended with animal manures and sewage sludge. J. Environ. Qual. 32:1114–1121.Song, O.R., S.J. Lee, Y.S. Lee, S.C. Lee, K.K. Kim, dan Y.L. Choi. 2008. Solubilization of insoluble inorganic phosphate by Burkholderia cepacia DA23 isolated from cultivated soil. Braz. J. Microbiol. 39: 151-156.Sridevi, M., K.V. Mallaiah, and N.C.S. Yadav. 2007. Phosphate solubilization by Rhizobium isolates from Crotalaria species. J. Plant Sci. 2: 635-639.Traina, S.J., G. Sposito, D. Hesterberg, dan U. Kafkafi. 1986. Effects of pH and organic acids on orthophosphate solubility in an acidic, montmorillonitic soil. Soil Sci. Am. J. 50: 45-52.Trivedi, P., and T. Sa. 2008. Pseudomonas corrugata (NRRL B-30409) mutants increased phosphate solubilization, organic acid production, and plant growth at lower temperatures. Curr. Microbiol. 56: 140-144.Tunesi, S., V. Poggi, and C. Gessa. 1999. Phosphate adsorption and precipitation in calcareous soils: The role of calcium ions in solution and carbonate minerals. Nutr. Cycling Agroecosyst. 53:219–227.Zhang, M., A.K. Alva, Y.C. Li, dan D.V. Calvert. 2001. Aluminium and iron fractions affecting phosphorus solubility and reactions in selected sandy soils. Soil Sci. 166: 940-948.with the solubilization of aluminum phosphate. Moreover, there is similarity in the production of organic acids related to the solubilization of aluminum phosphates and iron phosphate.

The physical, optical and luminescence properties of lithium aluminium phosphate glasses different doping europium oxide have been investigated to evaluate their properties for solid-state lighting applications. The density and molar volume measurements were carried out at room temperature. The absorption spectra were investigated in the UV-Vis-NIR region from 250 to 2500 nm. The emission spectra, excited with 394 nm excitation wavelength showed four emission transitions corresponding to 5D0→7F1 (591 nm), 5D0→7F2 (612 nm), 5D0→7F3 (648 nm) and 5D0→7F4 (698 nm). The optimal concentration of Eu2O3 in lithium aluminium phosphate glasses was 1.00 mol%.

AbstractSieleckiite is a new copper aluminium phosphate discovered at the Mt Oxide Copper Mine, 150 km north of Mt Isa, Queensland, Australia. It occurs with variscite, turquoise, libethenite and minor pseudomalachite in a fracture in a boulder of quartzite and shale. Sieleckiite forms deep sky blue to royal blue spheres up to 0.5 mm in diameter, made up of fibrous radiating crystals between 20 and 100 µm long and 1 to 2 µm wide. The mineral has a very pale blue streak and a pearly lustre on uneven fracture surfaces. Hardness is about 3 and the measured density is 3.02 g cm−3. The average of nine electron microprobe analyses gave CuO 32.39, Al2O3 26.57, P2O5 19.42%. Separate analyses gave H2O 18.1, CO2 1.6% (carbonate impurity). These data gave an empirical formula of Cu3.1Al4.0(PO4)2.1(OH)12.1.7H2O, calculated on the basis of 22 oxygen atoms. The simplified formula is Cu3Al4.0(PO4)2.1(OH)12.2H2O. The strongest lines in the X-ray powder diffraction pattern are {d(I)(hkl)}; 9.12(50)(100), 5.06(100)(101), 3.852(100)(111), 3.276(30)(2¯20), 2.827(50)(1¯02,102), 2.460(50)(3¯21). These data were indexed on a triclinic cell with a 9.41(8), b 7.56(5), c 5.95(6) Å, α 90.25(12)° β 91.27(12)° γ 104.02(7)° and a volume of 410.8(5) Å3. For Z = 1, the calculated density is 2.94 g cm−3. Optical properties could not be determined in full; the refractive indices are between 1.63 and 1.66, pleochroism is very weak from colourless to very pale blue.The mineral is named for the discoverer, Robert Sielecki (1958- ). Type specimens are preserved at the Museum of Victoria and the South Australian Museum. Sieleckiite was approved by the IMA Commission on New Minerals and Mineral Names prior to publication.

Phosphorus collectors made from filter paper and synthetic cloth, were tested to evaluate their feasibility of determining the need for phosphate application. The collectors were coated with two types of oxides, iron oxide and aluminium oxide. The capacity of the collectors was tested by placing them in a 2 mL of solution containing phosphorus (PO4(3-)) in the concentration of 0.0, 1.00, 3.00, 5.00, 7.00, 9.00 and 11.00 µ g.mL-1, respectively, after which they were placed in contact with four types of soil (LBa, LRd, LEd and Ca) and incubed for 0.0 and 24 h. In this test the soils were kept at a humidity equivalent to 150 mmHg suction. The amount of phosphorus extracted from the solutions was tested at intervals between 0,0 and 11.0 µ g of phosphorus/mL. Results indicated that collectors were most efficient in Dystrophic Dark-Red Latosol (LEd) and less efficient in "Bruno álico" Latosol (LBa) and Cambisol (Ca). Synthetic cloth was the support yielding the best performance, whereas iron oxide lining was the most adequate lining material. Phosphorus collection increased with time of incubation.

Anodic aluminium oxide fabricated at ambient temperature and low potential in phosphoric acid electrolyte was used as the working electrode for the electrochemical measurement of phosphate buffer saline under different pH conditions using the cyclic voltammetry tool. We investigate the reversibility of the electrochemical reaction as a redox reaction from the cyclic graphs that were obtained. We observed that the ratio of the peak current passed at both the reduction and oxidation when measured was very close to unity in all the pH but except one which produced a none reversible reaction with a non cyclic graph. The peak potential for both reduction and oxidation reactions using phosphate buffer saline as the analyte under different pH of 3, 5, 7, and 9 was also obtained.

Cette étude montre dans un premier temps qu'il est possible, à température ambiante et à l'état solide, de stabiliser le groupement feo#4#2# par substitution de fe(VI) par un atome x (x=s(+VI), cr(+VI), p(+V) et al(+III), par formation d'une solution solide k#2(fe#1##x,x#x)o#4. Nous avons montré que chromates et ferrates pouvaient constituer des solutions solides continues; avec les sulfates également, le sel de fer à oxyder a une incidence sur la teneur en fe(VI) du matériau fini; ainsi avec la jarosite, nous avons obtenu un mélange titrant a plus de 10% de fe(VI), alors qu'avec le sulfate ferreux, la teneur en fe(VI) n'excédait pas 7%. Les phosphates et aluminates sont moins favorables à la substitution des ferrates du fait de la charge différente des groupements tétraédriques. Au cours de ces différentes synthèses, nous avons également mis en évidence l'existence d'un nouveau sel ferrique de formule k#2feo(oh)#3 hydroscopique. Nous nous sommes intéressés, dans un deuxième temps, aux propriétés du sulfato-ferrate de potassium et plus particulièrement à sa stabilité thermique et sa stabilité en solution aqueuse. Nous avons dans un troisième temps, étudié l'efficacité des sulfato-ferrates de potassium dans le traitement des eaux usées urbaines d'une part et a potabilité d'autre part, en comparaison avec des réactifs couramment utilisés dans ce domaine, à savoir le chlorure ferrique et le sulfate d'aluminium hydrate. Les résultats obtenus quant à l'abattement de la D. C. O. , M. E. S. T. , phosphates, coliformes, métaux lourds, cyanures, pesticides et hydrocarbures sont de matière à envisager des tests à une plus grande échelle et ouvrent ainsi la voie à de nouvelles techniques de traitement des eaux

When the amorphous silicon (a-Si) dangling bonds are bonded to hydrogen the concentration of the dangling bond is decreased. The resulting film is called hydrogenated amorphous silicon (a-Si:H). The reduction in the dangling bonds concentration improves the optoelectrical properties of the film. The improved properties of a-Si:H makes it possible to manufacture electronic devices including a solar cell. A solar cell device based on the hydrogenated amorphous silicon (a-Si:H) was fabricated using the Hot-Wire Chemical Vapour Deposition (HWCVD). When an n-i-p solar cell configuration is grown, the norm is that the p-doped layer is deposited from a mixture of silane (SiH4) gas with diborane (B2H6). The boron atoms from diborane bonds to the silicon atoms and because of the number of the valance electrons, the grown film becomes a p-type film. Aluminium is a group 3B element and has the same valence electrons as boron, hence it will also produce a p-type film when it bonds with silicon. In this study the p-doped layer is grown from the co-deposition of a-Si:H from SiH4 with aluminium evaporation resulting in a crystallized, p-doped thin film. When this thin film is used in the n-i-p cell configuration, the device shows photo-voltaic activity. The intrinsic layer and the n-type layers for the solar cell were grown from SiH4 gas and Phosphine (PH3) gas diluted in SiH4 respectively. The individual layers of the solar cell device were characterized for both their optical and electrical properties. This was done using a variety of experimental techniques. The analyzed results from the characterization techniques showed the films to be of device quality standard. The analysed results of the ptype layer grown from aluminium showed the film to be successfully crystallized and doped. A fully functional solar cell was fabricated from these layers and the cell showed photovoltaic activity.
 

The main goal of this dissertation was to show that the principle of atomic layer deposition (ALD) can be applied to “endless” fibers. A reactor of atomic layer deposition has been designed, especially for coating depositions onto meter long bundles of fibers. Aluminum oxide (alumina), titanium oxide (titania), double layers of alumina and titania, as well as aluminium phosphate have been deposited onto bundles of carbon fibers using the home-built reactor. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images indicate that the coatings were uniform and conformal onto fiber surface. There was a good adhesion of the coatings to the fibers. Alumina has been deposited using two separate aluminum sources (aluminum trichloride and trimethylaluminum), and water as a source of oxygen. In case of alumina deposition using aluminum trichloride and water, initial deposition temperature was 500 °C. In these conditions, a part of the fiber bundle has been damaged. Thus, the deposition temperature was decreased to 300 °C and the fibers were unaffected. In addition, during this process hydrochloric acid is formed as a byproduct which is a corrosive substance and affects the reactor and there was a chloride impurity in the coatings. Thus, aluminum trichloride precursor was replaced by trimethylalumium. Alumina deposition onto carbon fibers using trimethylaluminum and water was carried out at a temperature of 77 °C. SEM images revealed that the fibers were unaffected and the coatings were uniform and conformal. Oxidation resistance of the carbon fibers was improved slightly after alumina deposition. Oxidation onset temperature of the uncoated fibers was about 630 °C. The resistance was linearly increased with the coating thickness (up to 660 °C) and getting saturated over a thickness of 120 nm. Titania coatings have been deposited using titanium tetrachloride and water. The physical appearances of the titania coatings were similar to the alumina coatings. The oxidation onset temperature of the titania coated carbon fibers was similar to the uncoated fibers but the rate of oxidation was decreased than the uncoated fibers. Two double layer coatings were deposited, alumina followed by titania (alumina/titania), and titania followed by alumina (titania/alumina). If the fibers were coated with the double layer of alumina/titania, they had almost same oxidation onset as alumina coated fibers but the rate of oxidation was decreased significantly compared to alumina coated fibers. This feature is independent of the thickness of the titania layers, at least in the regime investigated (50 nm alumina followed by 13 nm and 40 nm titania). On the other hand, the oxidation onset temperature of fibers coated with titania/alumina (20 nm titania /30 nm alumina) was approximately 750 °C. The fibers were burned completely when temperature was further increased to 900 °C and held another 60 minutes at 900 °C. This is significantly better than any other coating used in this dissertation. ALD of titania and alumina in principle was known beforehand, this dissertation here applies this knowledge for the first time to endless fibers. Furthermore, this dissertation shows for the first time that one can deposit aluminum phosphate via ALD (planar surface as well as fibers). Aluminum phosphate might be special interest in the fiber coating because it is a rather soft material and thus might be used to obtain a weak coupling between fiber and matrix in composites. Aluminum phosphate was deposited using trimethylaluminum and triethylphosphate as precursors. Energy dispersive X-ray spectroscopy and solid state nuclear magnetic resonance spectra confirmed that the coating comprises aluminum phosphate (orthophosphate as well as other stoichiometries). Scanning electron microscopic images revealed that coatings are uniform and conformal. In cases of alumina and titania, it was observed that the coatings were delaminated from the ends of cut fibers and thus formed of clear steps. On the other hand, for aluminum phosphate coating it was observed that the border between coating and underlying fiber often being smeared out and thus formed an irregular line. It seems in case aluminum phosphate cohesion is weaker than adhesion, thus it might be act a weak interface between fiber and matrix. Alumina, titania, and double layer microtubes have been obtained after selective removal of the underlying carbon fibers. The carbon fibers were selectively removed via thermal oxidation in air at temperatures exceeding 550 °C. SEM and TEM images indicate that the inner side of the tube wall has the same morphology like the fibers. In addition, it was observed that the individual microtubes were separated from their neighbors and they had almost uniform wall thicknesses. The longest tubes had a length of 30 cm
Das Hauptziel dieser Dissertation bestand darin nachzuweisen, dass die Atomlagenabscheidung (engl. atomic layer deposition (ALD)) auf „endlose“ Fasern angewendet werden kann. Es wurde ein Reaktor zur Atomlagenabscheidung gestaltet, der speziell für die Beschichtung meterlanger Faserbündel geeignet ist. Aluminiumoxid, Titanoxid, Doppelschichten aus Aluminiumoxid und Titanoxid sowie Aluminiumphosphat wurden mit Hilfe des selbstgebauten Reaktors auf Kohlefaserbündel abgeschieden. Rasterelektronenmikroskopische (REM) und transmissionselektronenmikroskopische (TEM) Aufnahmen zeigten, dass die Beschichtung auf den Fasern einheitlich und oberflächentreu war. Des Weiteren wurde eine gute Adhäsion zwischen Beschichtung und Fasern beobachtet. Das Prinzip der Beschichtung mit Titanoxid und Aluminiumoxid mit Hilfe der ALD war bereits vorher bekannt und im Rahmen dieser Dissertation jedoch erstmals auf "endlose" Fasern angewendet. Des Weiteren wird in dieser Dissertation erstmals gezeigt, dass es möglich ist, Aluminiumphosphat mittels ALD abzuscheiden (sowohl auf planaren Oberflächen als auch auf Fasern). Aluminiumphosphat könnte von besonderem Interesse in der Faserbeschichtung sein, da es ein relativ weiches Material ist und könnte daher als eine Art „schwacher“ Verbindung zwischen Faser und Matrix in Kompositen dienen. Die Oxidationsbeständigkeit von beschichten Kohlefasern wurde im Vergleich zu unbeschichteten Fasern bis zu einem gewissen Grad erhöht. Monoschichten von Aluminiumoxid und Titanoxid waren dafür wenig effektiv. Aluminiumphosphatbeschichtete Fasern waren deutlich besser geeignet als die beiden anderen. Eine Doppelschicht aus Titanoxid gefolgt von Aluminiumoxid verbesserte die Oxidationsbeständigkeit nochmals deutlich gegenüber allen anderen Beschichtungen, die in dieser Dissertation verwendet wurden. Mikroröhren aus Aluminiumoxid, Titanoxid und Doppelschichten wurden durch die selektive Entfernung der zugrunde liegenden Kohlefasern erhalten. Einzelne Mikroröhren waren von benachbarten Röhren getrennt und sie weisen eine nahezu einheitliche Wanddicke auf

碩士
義守大學
材料科學與工程學系
102
Tri-calcium phosphate(Ca3(PO4)2), hydroxyapatite(Ca10(PO4)6(OH)2), aluminum oxide(Al2O3), and hydroxide are used to prepare biocomposites in this study. This is because tri-calcium phosphate , hydroxyapatite, and aluminum oxide are bio-compatible with excellent mechanical properties. Among them, Ca10(PO4)6(OH)2 is similar to the composition of natural bone, and Al2O3 is bioisert. Except for these three materials, NaOH and KOH are added to react-sinter with them at low temperatures, which are 350℃ and 900℃, or 450℃ and 900℃, to observe dimension shrinkage and phase existence after sintering. In tradition, Ca10(PO4)6(OH)2 (HA) or Ca3(PO4)2 composites are mostly sintered at high temperatures, which are T>1000℃. In this study , under a sintering condition at 350℃ or 450℃, most of sintered Ca3(PO4)2 + Al2O3 , or Ca10(PO4)6(OH)2 + Al2O3 specimens show their linear shrinkage with 1~2%. When specimens being sintered at 900℃, some specimens show their densification rate up to 90%. As to phase existence of sintered specimens : HA+ Al2O3 composites contain. HA and α-Al2O3 crystal structures. Ca3(PO4)2 + Al2O3 composites contain β-Ca3(PO4)2 and α-Al2O3 crystal structures. whether α-Ca3(PO4)2 exists in these sintered specimens will be further discussed. As to microstructures, Ca3(PO4)2, Al2O3, and HA do not show any significant grain growth. As to the correlations among sample preparations, sintering mechanisms, and physical properties, are discussed in detail.

The field of advanced solution processed spin-coated electronics has rapidly expanded over the last few decades towards the development of low-cost, large area and low power consumer electronics for the design of system-on-panel, system-on-glass, and system-on-chip circuits. They have diverse applications such as wearable and textile integrated devices, seamless and twistable systems, soft skin systems, as well as roll-to-roll light-weight, transparent, conformable, stretchable, and even biodegradable systems. So far, all demonstration of solution processed electronics use thin lm transistors (TFT) without any memory. However, memory is an essential electronic component of all systems and it is important to realize floating gate ash memory devices using similar spin-coated solution processing compatible technique. The first demonstration of floating memory by Kahng and Size in 1967 on transparent glass substrates utilized floating metal gate charge storage layers deposited by high temperature vacuum technology. Since then, there has been intensive research on floating gate technology. However, the high temperature and high vacuum technology is incompatible with large area, flexible and low cost electronics due to the process integration issue. Hence the alternative challenge was taken up on developing solution processed spin-coated memory devices for sol-gel electronics. In this thesis we first introduce different solution processed dielectrics and oxide semi-conductors, thin lm deposition, and behavior at different processing temperatures. Further, we also demonstrate how the band structure of the dielectric, particularly the electron a finity, changes with annealing temperature. Then we propose and demonstrate a new high speed measurement technique for two terminal capacitive devices. In particular, we show that the entire capacitance-voltage curve can be measured in 2.5 s. The measurement is useful for characterization of two terminal capacitive memory devices in terms speed, endurance and retention. This achievement is followed by its application to newly developed fully solution processed, nanoparticle based, robust two terminal memory devices. The link between device performance and its structural and processing parameters such as annealing temperature, thickness of memory layer, supporting dielectric layer and substrate materials, is highlighted. In addition, a detailed analysis and comparison of performance of solution processed memory with regard to state-of-the art processing techniques as well as the selection of materials is presented. This work was extended to achieve the worlds first three terminal fully solution processed inorganic material-based robust ash memory devices with different kinds of solution processed charge trapping layers. We also discuss the advantage of this technology over previously reported sophisticated ultra high vacuum technology based three terminal ash memory devices. Afterwards, we report the discovery of deep level intrinsic traps in solution processed aluminium oxide phosphate. It is also shown that the traps are tunable with the processing temperature. Using XPS and UPS characterization techniques, the origin of these traps is linked with the molecular structure. Utilizing this trap behavior we have fabricated the worlds first fully solution processed ash memory device without tunneling and blocking layers at below 200 C. This discovery may be a breakthrough for large area, solution processed, and flexible electronics applications. Finally, conclusions are drawn on the performance of the memory stack with respect to other processing techniques, along with an outlook for this field and predictions for the future of this technology.

碩士
國立聯合大學
材料科學工程學系碩士班
99
This study explores optical, physical and structure properties based on zinc aluminum phosphate glass system (P2O5-ZnO-Al2O3) doped with different amounts of (terbium oxide), which changed the composition ratio between ZnO and P2O5. With increasing the terbium oxide and ZnO contents the density,refractive index and chemical durability of glasses increase, while the molar volume and thermal expansion coefficient decrease. Structure of glasses was analyzed by Fourier-transformed-infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy in glasses system. With decreasing P2O5 content and the increase of network modifier (ZnO) leak the bridge oxygen bonds and the non-bridging oxygen bonds increase. In the optical analysis, with terbium oxide exceed 2.5 mol% the glasses exhibiters maximum intensity of blue emission from 5D3 to 7Fj level, while green emission from 5D4 level has increases linearly up to 9 mol% of Tb2O3. The concentration quenching of blue emission (5D3→7Fj) is attributed mainly to the cross-relaxation among the excited and nearest neighbor unexcited Tb3+ ions in the glass matrix. The fluorescence intensity increases with the increasing of ZnO content. The ZnO photogenerated electrons are trapped in the band gap defects which lie next to the Tb3+ excited states, and energy transferred to Tb3+ ion through radiation less process.

Philosophiae Doctor - PhD
When the amorphous silicon (a-Si) dangling bonds are bonded to hydrogen the concentration of the dangling bond is decreased. The resulting film is called hydrogenated amorphous silicon (a-Si:H). The reduction in the dangling bonds concentration improves the optoelectrical properties of the film. The improved properties of a-Si:H makes it possible to manufacture electronic devices including a solar cell.A solar cell device based on the hydrogenated amorphous silicon (a-Si:H) was fabricated using the Hot-Wire Chemical Vapour Deposition (HWCVD). When an n-i-p solar cell configuration is grown, the norm is that the p-doped layer is deposited from a mixture of silane (SiH4) gas with diborane (B2H6). The boron atoms from diborane bonds to the silicon atoms and because of the number of the valance electrons, the grown film becomes a p-type film. Aluminium is a group 3B element and has the same valence electrons as boron, hence it will also produce a p-type film when it bonds with silicon.In this study the p-doped layer is grown from the co-deposition of a-Si:H from SiH4 with aluminium evaporation resulting in a crystallized, p-doped thin film. When this thin film is used in the n-i-p cell configuration, the device shows photo-voltaic activity.The intrinsic layer and the n-type layers for the solar cell were grown from SiH4 gas and Phosphine (PH3) gas diluted in SiH4 respectively. The individual layers of the solar cell device were characterized for both their optical and electrical properties. This was done using a variety of experimental techniques. The analyzed results from the characterization techniques showed the films to be of device quality standard. The analysed results of the ptype layer grown from aluminium showed the film to be successfully crystallized and doped.A fully functional solar cell was fabricated from these layers and the cell showed photovoltaic activity.

The main goal of this dissertation was to show that the principle of atomic layer deposition (ALD) can be applied to “endless” fibers. A reactor of atomic layer deposition has been designed, especially for coating depositions onto meter long bundles of fibers. Aluminum oxide (alumina), titanium oxide (titania), double layers of alumina and titania, as well as aluminium phosphate have been deposited onto bundles of carbon fibers using the home-built reactor. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images indicate that the coatings were uniform and conformal onto fiber surface. There was a good adhesion of the coatings to the fibers. Alumina has been deposited using two separate aluminum sources (aluminum trichloride and trimethylaluminum), and water as a source of oxygen. In case of alumina deposition using aluminum trichloride and water, initial deposition temperature was 500 °C. In these conditions, a part of the fiber bundle has been damaged. Thus, the deposition temperature was decreased to 300 °C and the fibers were unaffected. In addition, during this process hydrochloric acid is formed as a byproduct which is a corrosive substance and affects the reactor and there was a chloride impurity in the coatings. Thus, aluminum trichloride precursor was replaced by trimethylalumium. Alumina deposition onto carbon fibers using trimethylaluminum and water was carried out at a temperature of 77 °C. SEM images revealed that the fibers were unaffected and the coatings were uniform and conformal. Oxidation resistance of the carbon fibers was improved slightly after alumina deposition. Oxidation onset temperature of the uncoated fibers was about 630 °C. The resistance was linearly increased with the coating thickness (up to 660 °C) and getting saturated over a thickness of 120 nm. Titania coatings have been deposited using titanium tetrachloride and water. The physical appearances of the titania coatings were similar to the alumina coatings. The oxidation onset temperature of the titania coated carbon fibers was similar to the uncoated fibers but the rate of oxidation was decreased than the uncoated fibers. Two double layer coatings were deposited, alumina followed by titania (alumina/titania), and titania followed by alumina (titania/alumina). If the fibers were coated with the double layer of alumina/titania, they had almost same oxidation onset as alumina coated fibers but the rate of oxidation was decreased significantly compared to alumina coated fibers. This feature is independent of the thickness of the titania layers, at least in the regime investigated (50 nm alumina followed by 13 nm and 40 nm titania). On the other hand, the oxidation onset temperature of fibers coated with titania/alumina (20 nm titania /30 nm alumina) was approximately 750 °C. The fibers were burned completely when temperature was further increased to 900 °C and held another 60 minutes at 900 °C. This is significantly better than any other coating used in this dissertation. ALD of titania and alumina in principle was known beforehand, this dissertation here applies this knowledge for the first time to endless fibers. Furthermore, this dissertation shows for the first time that one can deposit aluminum phosphate via ALD (planar surface as well as fibers). Aluminum phosphate might be special interest in the fiber coating because it is a rather soft material and thus might be used to obtain a weak coupling between fiber and matrix in composites. Aluminum phosphate was deposited using trimethylaluminum and triethylphosphate as precursors. Energy dispersive X-ray spectroscopy and solid state nuclear magnetic resonance spectra confirmed that the coating comprises aluminum phosphate (orthophosphate as well as other stoichiometries). Scanning electron microscopic images revealed that coatings are uniform and conformal. In cases of alumina and titania, it was observed that the coatings were delaminated from the ends of cut fibers and thus formed of clear steps. On the other hand, for aluminum phosphate coating it was observed that the border between coating and underlying fiber often being smeared out and thus formed an irregular line. It seems in case aluminum phosphate cohesion is weaker than adhesion, thus it might be act a weak interface between fiber and matrix. Alumina, titania, and double layer microtubes have been obtained after selective removal of the underlying carbon fibers. The carbon fibers were selectively removed via thermal oxidation in air at temperatures exceeding 550 °C. SEM and TEM images indicate that the inner side of the tube wall has the same morphology like the fibers. In addition, it was observed that the individual microtubes were separated from their neighbors and they had almost uniform wall thicknesses. The longest tubes had a length of 30 cm.:Bibliographische Beschreibung und Referat 2 Abstract 4 List of abbreviations 10 1. General introduction and outline of this dissertation 12 1.1 References 20 2. Atomic layer deposition: Process and reactor 25 2.1 Introduction 25 2.2 Principle of atomic layer deposition 26 2.3 Materials and methods 29 2.3.1 Precursors 29 2.3.2 Precursors transportation 31 2.3.3 Carrier and purge gas 32 2.3.4 ALD reactors 32 2.4 Flow-Type ALD reactor for fiber coating 33 2.5 Conclusion 35 2.6 References 35 3. Single layer oxide coatings 38 3.1 State of the art 38 3.2 Alumina coating using non-flammable precursors 39 3.2.1 Introduction 39 3.2.Result and discussion 39 3.3 Alumina coating using organometallic precursor 46 3.2.1 Introduction 46 3.2.2 Results and discussion 46 3.4 Titania coating using titanium tetrachloride and water 59 3.4.1 Introduction 59 3.4.2 Results and discussion 59 3.5 Experimental Part 67 3.5.1 General experiments 67 3.5.2 Alumina coating using aluminum chloride and water 69 3.5.3 Alumina coating using trimethylalumium and water 69 3.5.4 Titania coating 72 3.6 Conclusions 72 3.7 References 74 4. Coating thickness and morphology 78 4.1 Introduction 78 4.2 Results and discussion 80 4.2.1 Purge time 15 s 81 4.2.2 Purge time 30 s 85 4.2.3 Purge time 45 s to 100 s 85 4.3 Experimental part 88 4.4 Conclusions 89 4.5 References 89 5. Alumina and titania double layer coatings 91 5.1 Introduction 91 5.2 Results and discussion 92 5.3 Experimental part 102 5.4 Conclusions 103 5.5 References 103 6. Atomic layer deposition of aluminum phosphate 105 6.1 Introduction 105 6.2 Results and discussion 106 6.3 Experimental part 113 6.4 Conclusions 114 6.5 References 115 7. Alumina microtubes 117 7.1 Introduction 117 7.2 Results and discussion 118 7.2.1 Fibers before coating deposition 118 7.2.2 Coatings on the carbon fibers 118 7.2.3 Microtubes 121 7.3 Experimental part 127 7.4 Conclusions 128 7.5 References 128 8. Conclusions 131 Acknowledgements 136 Curriculum Vitae 138 Selbständigkeitserklärung 142
Das Hauptziel dieser Dissertation bestand darin nachzuweisen, dass die Atomlagenabscheidung (engl. atomic layer deposition (ALD)) auf „endlose“ Fasern angewendet werden kann. Es wurde ein Reaktor zur Atomlagenabscheidung gestaltet, der speziell für die Beschichtung meterlanger Faserbündel geeignet ist. Aluminiumoxid, Titanoxid, Doppelschichten aus Aluminiumoxid und Titanoxid sowie Aluminiumphosphat wurden mit Hilfe des selbstgebauten Reaktors auf Kohlefaserbündel abgeschieden. Rasterelektronenmikroskopische (REM) und transmissionselektronenmikroskopische (TEM) Aufnahmen zeigten, dass die Beschichtung auf den Fasern einheitlich und oberflächentreu war. Des Weiteren wurde eine gute Adhäsion zwischen Beschichtung und Fasern beobachtet. Das Prinzip der Beschichtung mit Titanoxid und Aluminiumoxid mit Hilfe der ALD war bereits vorher bekannt und im Rahmen dieser Dissertation jedoch erstmals auf "endlose" Fasern angewendet. Des Weiteren wird in dieser Dissertation erstmals gezeigt, dass es möglich ist, Aluminiumphosphat mittels ALD abzuscheiden (sowohl auf planaren Oberflächen als auch auf Fasern). Aluminiumphosphat könnte von besonderem Interesse in der Faserbeschichtung sein, da es ein relativ weiches Material ist und könnte daher als eine Art „schwacher“ Verbindung zwischen Faser und Matrix in Kompositen dienen. Die Oxidationsbeständigkeit von beschichten Kohlefasern wurde im Vergleich zu unbeschichteten Fasern bis zu einem gewissen Grad erhöht. Monoschichten von Aluminiumoxid und Titanoxid waren dafür wenig effektiv. Aluminiumphosphatbeschichtete Fasern waren deutlich besser geeignet als die beiden anderen. Eine Doppelschicht aus Titanoxid gefolgt von Aluminiumoxid verbesserte die Oxidationsbeständigkeit nochmals deutlich gegenüber allen anderen Beschichtungen, die in dieser Dissertation verwendet wurden. Mikroröhren aus Aluminiumoxid, Titanoxid und Doppelschichten wurden durch die selektive Entfernung der zugrunde liegenden Kohlefasern erhalten. Einzelne Mikroröhren waren von benachbarten Röhren getrennt und sie weisen eine nahezu einheitliche Wanddicke auf.:Bibliographische Beschreibung und Referat 2 Abstract 4 List of abbreviations 10 1. General introduction and outline of this dissertation 12 1.1 References 20 2. Atomic layer deposition: Process and reactor 25 2.1 Introduction 25 2.2 Principle of atomic layer deposition 26 2.3 Materials and methods 29 2.3.1 Precursors 29 2.3.2 Precursors transportation 31 2.3.3 Carrier and purge gas 32 2.3.4 ALD reactors 32 2.4 Flow-Type ALD reactor for fiber coating 33 2.5 Conclusion 35 2.6 References 35 3. Single layer oxide coatings 38 3.1 State of the art 38 3.2 Alumina coating using non-flammable precursors 39 3.2.1 Introduction 39 3.2.Result and discussion 39 3.3 Alumina coating using organometallic precursor 46 3.2.1 Introduction 46 3.2.2 Results and discussion 46 3.4 Titania coating using titanium tetrachloride and water 59 3.4.1 Introduction 59 3.4.2 Results and discussion 59 3.5 Experimental Part 67 3.5.1 General experiments 67 3.5.2 Alumina coating using aluminum chloride and water 69 3.5.3 Alumina coating using trimethylalumium and water 69 3.5.4 Titania coating 72 3.6 Conclusions 72 3.7 References 74 4. Coating thickness and morphology 78 4.1 Introduction 78 4.2 Results and discussion 80 4.2.1 Purge time 15 s 81 4.2.2 Purge time 30 s 85 4.2.3 Purge time 45 s to 100 s 85 4.3 Experimental part 88 4.4 Conclusions 89 4.5 References 89 5. Alumina and titania double layer coatings 91 5.1 Introduction 91 5.2 Results and discussion 92 5.3 Experimental part 102 5.4 Conclusions 103 5.5 References 103 6. Atomic layer deposition of aluminum phosphate 105 6.1 Introduction 105 6.2 Results and discussion 106 6.3 Experimental part 113 6.4 Conclusions 114 6.5 References 115 7. Alumina microtubes 117 7.1 Introduction 117 7.2 Results and discussion 118 7.2.1 Fibers before coating deposition 118 7.2.2 Coatings on the carbon fibers 118 7.2.3 Microtubes 121 7.3 Experimental part 127 7.4 Conclusions 128 7.5 References 128 8. Conclusions 131 Acknowledgements 136 Curriculum Vitae 138 Selbständigkeitserklärung 142

In an agrarian economy-dominated livelihood system, soil factor considered to be an essential determinant to prioritize the choice for crop selection and productivity. The laterite soil is formed under conditions of high temperature and heavy rainfall with alternate wet and dry periods, which leads to leaching of soil, leaving only oxides of iron and aluminum. It lacks fertility due to a lower base-exchanging capacity and a lower content of nitrogen, phosphorus, and potassium. Laterite soil is found in the western plateau region (mainly found in the parts of Birbhum, Bardhaman, Bankura, Purulia, West Midnapore districts) of West Bengal. This soil is red in colour, acidic in nature (from 5.5 to 6.5 approx.) and poor in organic matter, calcium, phosphates and nitrogen. Overall, leaching under slight to very high soil erosion makes this soil infertile; though with proper irrigation facilities, scope of growing vegetation and cultivation can be possible in this soil. It has been observed that, Increase in yield of paddy with nitrogen is not significant in cultivation; but, when phosphate is added along with it high responses are obtained, indicating a typical phosphate deficient tract. The present paper tries to highlight on the factors responsible for the limited scope of agricultural productivity on lateritic tracts of West Bengal, which need to be addressed for effective land use planning and management in future.

In Chapter 4, when the electrostatic adsorption of anions by variable charge soils is discussed, another type of adsorption, specific adsorption, has already been mentioned, although it is not very remarkable for chloride ions and nitrate ions. For some other anions, specific adsorption can be very important. Specific adsorption is determined by the nature of the anions and is also related to the kind of functional groups on the surface of soils. In general, this type of adsorption is more pronounced in soils containing large amounts of iron and aluminum oxides. Therefore, specific adsorption of anions is one of the important characteristics of variable charge soils. Specific adsorption is a common term. For anions, the mechanism of specific adsorption is ligand exchange between these ions and some groups that have already been coordinately linked on the surface of soil particles. Therefore, the term coordination adsorption may be more appropriate than the term specific adsorption. For variable charge soils, phosphate is the strongest specifically adsorbed anion species. Phosphate adsorption is also the most intensively studied anion adsorption in soil science. However, the valence status of phosphate ions is apt to change with the change in environmental conditions. In the adsorption of phosphate by soils, in addition to ligand exchange, other mechanisms, such as chemical precipitation, may also be involved. Therefore, the phenomenon of phosphate adsorption is rather complex, and it is often difficult to make definitive interpretations of experimental results. In the present chapter, the coordination adsorption of anions will be discussed, mainly taking sulfate as the example, because sulfate is only secondary to phosphate in importance for agricultural production among anions capable of undergoing coordination adsorption. For the purpose of comparison, the adsorption of fluoride ions will also be mentioned. On the surface of soil particles there are functional groups such as hydroxyl groups (M-OH) and water molecules (M-OH2) that can participate in ligand exchange with anions. Al-OH, Fe-OH, Al-OH2, and Fe-OH2 groups on the surface of soil particles are the important sites for coordination adsorption of anions. Therefore, when a soil contains large amounts of iron and aluminum oxides, the phenomenon of coordination adsorption of anions will be more pronounced.

Abstract Use of high-chlorine and alkali containing fuels such as biomass and refuse is increasing in production of heat and electricity. Fluidized bed boilers experience severe and harsh conditions, in which high temperatures combined with inhomogenous fuel cause severe material wastage to metallic parts in boilers. Thermally sprayed coatings have been reported to provide protection to the boiler tubes. However, thermally sprayed coatings have encountered serious problems, when corrosion has proceeded to the substrate material through voids and oxides in lamella boundaries. Sealing of the coatings can solve these problems. Sealing of coatings with commercial sealants and laser fusion treatment was investigated. Thermally sprayed HVOF metallic coatings were sealed with different commercial sealing agents and diode laser. The coatings were tested in molten salt, simulating condition of fluidized bed boiler superheaters. Optical microscopy (OM), scanning electron microscopy (SEM) and energy dispersive X-ray analysator (EDX) were used for examination of the tested and non-tested specimens. Some of the tested sealants protected the coatings adequately in the short time alkali chloride - alkali sulphate exposure test. Best sealant contained aluminium oxide and aluminium phosphate. Laser treated coatings had good corrosion resistance in a short-term test.

Abstract Microstructural study of plasma sprayed chromia coatings sealed with aluminum phosphate, was carried out for determining strengthening mechanisms of the sealant. Characterization was accomplished by X-ray diffractometry, scanning electron microscopy, and analytical transmission electron microscopy. The main phase in the coating is the eskolaite type α-Cr2O3. The overall structure of the coating is lamellar with columnar grains parallel to the lamella thickness. Amorphous aluminum phosphate sealant has penetrated into the coating filling the structural defects such as cracks, gaps and pores between the lamellas. The average composition of the sealant in the coating is 25 at% aluminum and 75 at% phosphorus giving the molar ratio P/Al of 3, that corresponds to metaphosphates Al(PO3)3. The aluminum phosphate sealing in the chromium oxide coatings is based on adhesive binding due to the attractive forces between the condensed phosphates and the coating. There were no indications about chemical binding due to reactions between the sealant and the coating in the sealing treatment for chromia coatings.

Abstract The main focus of this study is sealed zirconia-based thermal barrier coatings produced by plasma spraying. AEM examinations conducted on phosphate-sealed Y2O3-ZrO2 coatings and orthophosphoric acid sealed MgO-ZrO2 coatings provide detailed information on the phases in the sealed coatings and the bonding mechanism of phosphate-based sealants on zirconia. In the case of aluminum phosphate sealed alumina and chromia, the primary objective is to add clarity on the bonding mechanism by means of transmission electron microscopy. Investigations of the sealing-layer interface indicate that the sealing of the layer lamellas is due to chemical reactions. Paper includes a German-language abstract.

Abstract Several recently published studies have shown remarkable improvements in dry abrasion resistance and corrosion resistance of aluminum phosphate sealed oxide coatings when compared to unsealed ones. There are numerous applications in chemical industry where a corrosive environment is accompanied with abrasive or erosive particles. In this study the wet abrasion resistance and slurry erosion resistance of aluminum phosphate-sealed and unsealed oxide coatings were studied and compared to their dry abrasion resistance. In wet abrasion tests kaolin and water mixture was used as the abrasive. In slurry erosion tests several abrasives in water with various pH values was used as the erosive medium. The coatings were characterized for microstructure and their wear mechanisms were analyzed using SEM. The results from wear tests are reported and correlated with coating properties. The influence of coating quality to the relative improvement achieved by sealing is presented and discussed.

Abstract A typical structure of thermal spray coatings consisted of molten particles, semi-molten particles, oxides, pores and cracks. These factors caused the porosity of sprayed coatings, leading to a great influence on the coating properties, especially their wear-corrosion resistance. In this study, a post-spray sealing treatment of Cr3C2-NiCr/Al2O3-TiO2 plasma sprayed coatings was carried out, then their corrosion properties were evaluated, before and after the treatment. For sealing process, aluminum phosphate (APP) containing aluminum oxide (Al2O3) nanoparticles (~10 nm) was used. The permeability of APP into the sprayed coating was analyzed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The treatment efficiency for porosity and corrosion resistance of sprayed coatings were evaluated by electrochemical measurements, such as the potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, the wear-corrosion resistance of the sealed coating was examined in 3.5 wt.% NaCl circulation solution containing 0.25 wt.% SiO2 particles. The obtained results showed that APP penetrated deeply through the sprayed coating. The incorporation of Al2O3 nanoparticles into APP sealant enhanced the treatment efficiency of porosity for sprayed coating. The effect of the post-treatment on corrosion protection of the sprayed coating has been discussed.

Abstract In this investigation, titanium dioxide and hydroxyapatite (HA) suspensions are plasma sprayed onto stainless steel, titanium, and aluminum substrates and the structure and properties of the resulting layers are correlated with spraying conditions. The suspensions were formulated with fine TiO2 pigment and HA milled from spray-dried powder or synthesized from calcium nitrate and ammonium phosphate. In some experiments, an atomizer was used to inject the suspensions into the plasma jet, and in others, the suspensions were fed into the jet using continuous stream injection. The deposits are characterized on the basis of morphology, chemical and phase composition, scratch hardness, and dielectric strength.

Abstract In this paper, different aluminum phosphate sealing treatment temperatures and substrate preheating temperatures are used to produce different coating properties. X -ray residual stress analyzer is used as a NDT inspection method to find out undesired coating defects. The wear properties of plasma-sprayed aluminum oxide and chromium oxide coatings are studied as a function of spray parameters and post-treatments. The residual stress states are associated with other coating properties such as dry wear resistance. Hardness and porosity as well as microstructure compared. The aim of this paper is to find connections between residual stresses and other coating properties. It was observed that there is good correlation between stress state, abrasion resistance and sealing treatment temperature when considering chromia coatings. Paper includes a German-language abstract.

Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.