Laboratory experiments on simultaneous removal of K and P from synthetic and real urine for nutrient recycle by crystallization of magnesium–potassium–phosphate–hexahydrate in a draft tube and baffle reactor

Chemosphere ◽  
2012 ◽  
Vol 88 (2) ◽  
pp. 219-223 ◽  
Author(s):  
Kangning Xu ◽  
Chengwen Wang ◽  
Xiaoxue Wang ◽  
Yi Qian
Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 940 ◽  
Author(s):  
Ha T.H. Nguyen ◽  
Masayuki Sakakibara ◽  
Minh N. Nguyen ◽  
Nhuan T. Mai ◽  
Vinh T. Nguyen

Silicon (Si) has been recently reconsidered as a beneficial element due to its direct roles in stimulating the growth of many plant species and alleviating metal toxicity. This study aimed at validating the potential of an aquatic macrophyte Eleocharis acicularis for simultaneous removal of heavy metals from aqueous solutions under different dissolved Si. The laboratory experiments designed for determining the removal efficiencies of heavy metals were conducted in the absence or presence of Si on a time scale up to 21 days. Eleocharis acicularis was transplanted into the solutions containing 0.5 mg L−1 of indium (In), gallium (Ga), silver (Ag), thallium (Tl), copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) with various Si concentrations from 0 to 4.0 mg L−1. The results revealed that the increase of dissolved Si concentrations enhanced removal efficiencies of E. acicularis for Ga, Cu, Zn, Cd, and Pb, while this increase did not show a clear effect for In, Tl, and Ag. Our study presented a notable example of combining E. acicularis with dissolved Si for more efficient removals of Cu, Zn, Cd, Pb, and Ga from aqueous solutions. The findings are applicable to develop phytoremediation or phytomining strategy for contaminated environment.


1992 ◽  
Vol 6 (2) ◽  
pp. 269-275 ◽  
Author(s):  
Rakesh Jain ◽  
Chester L. Foy

The influence of various nutrients on parasitism of tomato plants by Egyptian broomrape and on stimulation of broomrape seed germination by strigol analogs was investigated in greenhouse and laboratory experiments. Parasitism occurred most readily in potting media low in fertility. Addition of nitrogenous compounds to potting media resulted in inhibition of broomrape parasitism. Ammonium nitrate with potassium phosphate or ammonium phosphate alone was most effective in reducing parasitism and enhancing growth of tomato plants. In the laboratory, strigol analogs induced 55% germination in broomrape seeds preconditioned in distilled water. Seeds preconditioned in distilled water or various salt solutions, but not treated with strigol analogs, showed 18% germination. GR 24 (5 μM) induced higher germination in seeds preconditioned in 10 mM ammonium nitrate, with or without potassium phosphate, compared with seeds preconditioned in sodium chloride. Preconditioning of seeds in sodium nitrate (10 mM) and treating with GR 24 stimulated, whereas preconditioning of seeds in ammonium salts (1 mM ammonium sulfate or 10 mM urea) and treating with GR 24 inhibited germination significantly.


1999 ◽  
Vol 173 ◽  
pp. 365-370
Author(s):  
Kh.I. Ibadinov

AbstractFrom the established dependence of the brightness decrease of a short-period comet dependence on the perihelion distance of its orbit it follows that part of the surface of these cometary nuclei gradually covers by a refractory crust. The results of cometary nucleus simulation show that at constant insolation energy the crust thickness is proportional to the square root of the insolation time and the ice sublimation rate is inversely proportional to the crust thickness. From laboratory experiments resulted the thermal regime, the gas productivity of the nucleus, covering of the nucleus by the crust, and the tempo of evolution of a short-period comet into the asteroid-like body studied.


Author(s):  
M. H. Wheeler ◽  
W. J. Tolmsoff ◽  
A. A. Bell

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.


Author(s):  
S. S. Breese ◽  
H. L. Bachrach

Models for the structure of foot-and-mouth disease virus (FMDV) have been proposed from chemical and physical measurements (Brown, et al., 1970; Talbot and Brown, 1972; Strohmaier and Adam, 1976) and from rotational image-enhancement electron microscopy (Breese, et al., 1965). In this report we examine the surface structure of FMDV particles by high resolution electron microscopy and compare it with that of particles in which the outermost capsid protein VP3 (ca. 30, 000 daltons) has been split into smaller segments, two of which VP3a and VP3b have molecular weights of about 15, 000 daltons (Bachrach, et al., 1975).Highly purified and concentrated type A12, strain 119 FMDV (5 mg/ml) was prepared as previously described (Bachrach, et al., 1964) and stored at 4°C in 0. 2 M KC1-0. 5 M potassium phosphate buffer at pH 7. 5. For electron microscopy, 1. 0 ml samples of purified virus and trypsin-treated virus were dialyzed at 4°C against 0. 2 M NH4OAC at pH 7. 3, deposited onto carbonized formvar-coated copper screens and stained with phosphotungstic acid, pH 7. 3.


Author(s):  
G. M. Cohen ◽  
J. S. Grasso ◽  
M. L. Domeier ◽  
P. T. Mangonon

Any explanation of vestibular micromechanics must include the roles of the otolithic and cupular membranes. However, micromechanical models of vestibular function have been hampered by unresolved questions about the microarchitectures of these membranes and their connections to stereocilia and supporting cells. Otolithic membranes are notoriously difficult to preserve because of severe shrinkage and loss of soluble components. We have empirically developed fixation procedures that reduce shrinkage artifacts and more accurately depict the spatial relations between the otolithic membranes and the ciliary bundles and supporting cells.We used White Leghorn chicks, ranging in age from newly hatched to one week. The inner ears were fixed for 3-24 h in 1.5-1.75% glutaraldehyde in 150 mM KCl, buffered with potassium phosphate, pH 7.3; when postfixed, it was for 30 min in 1% OsO4 alone or mixed with 1% K4Fe(CN)6. The otolithic organs (saccule, utricle, lagenar macula) were embedded in Araldite 502. Semithin sections (1 μ) were stained with toluidine blue.


Author(s):  
Ruth V.W. Dimlich

Mast cells in the dura mater of the rat may play a role in cerebral pathologies including neurogenic inflammation (vasodilation; plasma extravasation) and headache pain . As has been suggested for other tissues, dural mast cells may exhibit a close spatial relationship to nerves. There has been no detailed ultrastructural description of mast cells in this tissue; therefore, the goals of this study were to provide this analysis and to determine the spatial relationship of mast cells to nerves and other components of the dura mater in the rat.Four adult anesthetized male Wistar rats (290-400 g) were fixed by perfusion through the heart with 2% glutaraldehyde and 2.8% paraformaldehyde in a potassium phosphate buffer (pH 7.4) for 30 min. The head of each rat was removed and stored in fixative for a minimum of 24 h at which time the dural coverings were removed and dissected into samples that included the middle meningeal vasculature. Samples were routinely processed and flat embedded in LX 112. Thick (1 um) sections from a minimum of 3 blocks per rat were stained with toluidine blue (0.5% aqueous).


2010 ◽  
Vol 9 (2) ◽  
pp. 69-78 ◽  
Author(s):  
David De Cremer ◽  
Maarten Wubben

The present research examined how voice procedures and leader confidence affect participants’ negative emotions and willingness to withdraw. It was predicted that receiving voice would be valued out of instrumental concerns, but only when the enacting leader was high in confidence. Two laboratory experiments indeed showed an interaction between type of voice (pre-decisional vs. post-decisional) and leader’s confidence (low vs. high) on participants’ negative emotions and willingness to withdraw. In particular, post-decision voice only led to more negative responses than did pre-decision voice when the enacting leader was high in confidence. Negative emotions mediated this interaction effect of type of voice on willingness to withdraw. Implications for integrating the leadership and procedural justice literatures are discussed.


1968 ◽  
Vol 13 (10) ◽  
pp. 536-536
Author(s):  
Peter G. Polson

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