Interactions Between Exogenous Rare Earth Elements and Phosphorus Leaching in Packed Soil Columns

Through leaching experiments and simulated rainfall experiments, characteristics of vertical leaching of exogenous rare earth elements (REEs) and phosphorus (P) and their losses with surface runoff during simulated rainfall in different types of soils (terra nera soil, cinnamon soil, red soil, loess soil, and purple soil) were investigated. Results of the leaching experiments showed that vertical transports of REEs and P were relatively low, with transport depths less than 6 cm. The vertical leaching rates of REEs and P in the different soils followed the order of purple soil > terra nera soil > red soil > cinnamon soil > loess soil. Results of the simulated rainfall experiments (83 mm h(-1)) revealed that more than 92% of REEs and P transported with soil particles in runoff. The loss rates of REEs and P in surface runoff in the different soil types were in the order of loess soil > terra nera soil > cinnamon soil > red soil > purple soil. The total amounts of losses of REEs and P in runoff were significantly correlated.

Model analysis of dissolved inorganic phosphorus exports from the Yangtze river to the estuary

In this paper, we estimate the inputs of phosphorus (P) to the Yangtze River Basin and exports of dissolved inorganic phosphorus (DIP) from the river to the estuary for the period 1970-2003, by using the global NEWS-DIP model. Modeled DIP yields range from 2.5 kg P km(-2) yr(-1) in 1970 to 4.6 kg P km(-2) yr(-1) in 1985, and then dramatically increase to 14.1 kg P km(-2) yr(-1) in 2003. No significant difference between the modeled and measured values at the level of P = 0.05 is observed. The study also demonstrates variable source contributions of P to the modeled DIP during the period 1970-2003. Point sewage P input accounted for approximately 100% in the period 1970-1985 and substantially decreased to 24.8% in 2003. Chemical fertilizer contributed 25.4% of DIP yields in 1986 and increased continuously to 50.3% in 2003, while a stable trend in manure P contribution averaging 22.9% of DIP yields was shown in the same period. The study concludes that P inputs to the Yangtze River Basin and the river DIP export to the estuary have substantially increased during the study period consequence to human pressure.

Carbon-supported Pd nanocatalyst modified by non-metal phosphorus for the oxygen reduction reaction

A carbon-supported palladium catalyst modified by non-metal phosphorus(PdP/C) has been developed as an oxygen reduction catalyst for direct methanol fuel cells.The PdP/C catalyst was prepared by the sodium hypophosphite reduction method. The as-prepared Pd nanoparticles have a narrow size distribution with an average diameter of 2 nm. Energy dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD) results indicate that P enters into the crystal lattice of Pd and forms an alloy.

The extraction of rare earths using mixtures of acidic phosphorus-based reagents or their thio-analogues

The solvent extraction of rare earths from chloride solution has been investigated using mixtures of 2-ethylhexylphosphonic acid mono-(2-ethylhexyl) ester (HEHEHP, P507) and organophosphorus acids [di-(2-ethylhexyl)phosphoric acid (HDEHP, P204), isopropylphosphonic acid 1-hexyl-4-ethylocryl ester (HHEOIPP), bis(2,4,4-trimethylpentyl)phosphinic acid (Cyanex 272), bis(2,4,4-trimethylpentyl)monothiophosphinic acid (Cyanex 302), and bis(2,4,4-trimethypentyl)dithiophosphinic acid (Cyanex 301)]. Results show that the extractability of the selected extractants for rare earths decreases in the order: HEHEHP/HDEHP > HEHEHP/Cyanex 301 > HEHEHP/HHEOIPP > HEHEHP/Cyanex 302 > HEHEHP/Cyanex 272. A possible explanation of the different extractabilities is given based on the structure of the extractants. Furthermore, the possibilities of the separation of adjacent rare earths with these mixtures were investigated according to the extractabilities; the results show the possibility of separating the rare earths.

A highly reduced polyoxoanion with phosphorus-centered alternate layers of Mo/V oxides, [(PMo2Mo6V4O40)-Mo-V-V-VI-O-IV((VO)-O-IV)(2)](9-)

An unusual polyoxometalate [H2N(C2H4)(2)NH2](4)(H3O)[(PMO2Mo6V4O40)-Mo-V-V-VI-O-IV((VO)-O-IV)(2)].H2O is hydrothermally synthesized and characterized by IR, UV-VIS, elemental analyses, X-ray photoelectron spectrum, ESR, TG and Single crystal X-ray diffraction. The title compound crystallizes in the orthorhombic space group Pbca with a = 15-227(5), b = 19.491(4), c = 18.737(3) Angstrom, V = 5123(2) Angstrom(3), Z = 4, and R-1 (wR(2)) = 0.0726(0.1416). The compound contains an unusual highly reduced pseudo-Keggin type polyoxoanion and exhibits an interesting phosphorus-centered alternate arrangement of layers of molybdenum and vanadium oxides.

A MASS-SPECTROMETRIC STUDY OF ORGANIC PHOSPHORUS-COMPOUNDS .5. EI SPECTRA OF 1, 3, 2-OXAZAPHOSPHOLIDINE 2-SULFIDES DERIVATES

The mass spectral behaviour of 15 new type of organic phosphorus compounds with a considerable insecticidal activity, 1, 3,2-oxazaphospholidine 2-sulfides derivatives, under 70 eV electron impact has been studied by means of high and low resolution mass spectrometry as well as by B/E linked scan and MIKES/CID analysis. Discussion is focused into the isomerization between oxygen and sulphur in molecules and some rearrangement reactions.

GENERAL ALPHA-N INDEX AND ITS APPLICATION .2. THE CORRELATION BETWEEN THE GENERAL ALPHA-N INDEX AND PHYSICAL-PROPERTIES OF NEUTRAL PHOSPHORUS-COMPOUNDS

The relationship between the alpha-N index and physical properties of neutral phosphorus extractants is studied. Using the general alpha-N index which could describe extractants with minute difference in structure, the good correlation between it and various physical properties of the neutral phosphorus extractants (e.g., densities, refractive index, shift ratio of paper chromatography and IR frequencies of bond P = O) is obtained. The result indicates that general alpha-N index is a good topological index of organic compounds.

GENERAL ALPHA-N INDEX AND ITS APPLICATION .1. GENERAL ALPHA-N INDEX AND ITS APPLICATION IN THE EXTRACTION OF Y, CE, U, AND TH BY NEUTRAL PHOSPHORUS EXTRACTANCTS

The general a(N) index is established for molecules containing heteroatoms, rings, and multiple bonds. The general a(N) index is able to describe molecules with minute differences in structure and can also reveal the properties of molecules. This theory is successfully applied to the case of neutral phosphorus extractants. Both the molecular polarity and steric effect are characterized by the general a(N) index. The relationships between these properties and the distribution ratios for extracting Y, Ce, U, and Th are also shown by the general a(N) index.