Modelling heterogeneous phosphate sorption kinetics on iron oxyhydroxides and soil with a continuous distribution approach

2018 ◽  
Vol 69 (3) ◽  
pp. 475-487 ◽  
Author(s):  
R. Warrinnier ◽  
T. Goossens ◽  
S. Braun ◽  
J. P. Gustafsson ◽  
E. Smolders
Keyword(s):  
Continuous Distribution ◽  
Sorption Kinetics ◽  
Iron Oxyhydroxides ◽  
Phosphate Sorption

Modelling phosphate-sorption kinetics in acid soils

1995 ◽  
Vol 46 (2) ◽  
pp. 239-245 ◽  
Author(s):  
D. FREESE ◽  
W.H. RIEMSDIJK ◽  
S.E.A.T.M. ZEE
Keyword(s):  
Acid Soils ◽  
Sorption Kinetics ◽  
Phosphate Sorption

scholarly journals Kinetics, thermodynamics and mechanisms of phosphate sorption onto bottle gourd biomass modified by (3-chloro-2-hydroxypropyl) trimethylammonium chloride

2019 ◽  
Vol 44 (3) ◽  
pp. 267-285 ◽  
Author(s):  
Dragana Z Marković-Nikolić ◽  
Milorad D Cakić ◽  
Goran Petković ◽  
Goran S Nikolić
Keyword(s):  
Thermodynamic Parameters ◽  
Quaternary Ammonium ◽  
Sorption Kinetics ◽  
Phosphate Removal ◽  
Bottle Gourd ◽  
Effect Of Temperature ◽  
Trimethylammonium Chloride ◽  
Phosphate Sorption ◽  
Maximum Sorption Capacity ◽  
Non Linear

The sorption kinetics and thermodynamic parameters of phosphate removal from aqueous solution using quaternary ammonium–modified bottle gourd biomass as a sorbent were studied in a batch reactor. The cationic sorbent, containing trimethylammonium and hydroxypropyl groups, was obtained through the chemical reactions of the lignocellulosic Lagenaria vulgaris shell with (3-chloro-2-hydroxypropyl)trimethylammonium chloride. Experimental data of phosphate sorption from aqueous solutions of different initial concentrations (5–140 mg P L−1) have been analysed by reaction kinetics and diffusion models. The characteristic rate constants calculated by linear and non-linear regression analyses of the experimental results are presented. The phosphate sorption reaches equilibrium in 20–30 min, depending on the initial phosphate concentration. The maximum sorption capacity of quaternary ammonium–modified bottle gourd (QABG) sorbent was 18 mg P g−1 at 20 oC. The sorption system is best described by a non-linear equation of the pseudo first-order model ( R2 > 0.996). The Weber–Morris model indicated that the sorption process took place in three steps, whereby the intra-particle diffusion is not the only rate-controlling step. In addition, the effect of temperature (20 oC–50 oC) on sorption kinetics was also investigated. The various thermodynamic parameters suggest that phosphate sorption is favoured and is an exothermic process. The activation energy and the sticking probability confirmed that anion exchange is the dominant mechanism. These results provide valuable information for the potential use of agricultural residues in the treatment of wastewaters.

Sorption, kinetics and thermodynamics of phosphate sorption onto soybean stover derived biochar

2017 ◽  
Vol 8 ◽  
pp. 113-125 ◽  
Author(s):  
Rajasekar Karunanithi ◽  
Yong Sik Ok ◽  
Rajarathnam Dharmarajan ◽  
Mahtab Ahmad ◽  
Balaji Seshadri ◽  
...  
Keyword(s):  
Sorption Kinetics ◽  
Kinetics And Thermodynamics ◽  
Phosphate Sorption

Restructuring of polygalacturonate on alumina upon hydration—Effect on phosphate sorption kinetics

2006 ◽  
Vol 70 (12) ◽  
pp. 2957-2969 ◽  
Author(s):  
Christian Mikutta ◽  
Jaane Krüger ◽  
Gabriele E. Schaumann ◽  
Friederike Lang
Keyword(s):  
Sorption Kinetics ◽  
Phosphate Sorption ◽  
Hydration Effect

Calculation of structure images of crystalline defects

1978 ◽  
Vol 36 (1) ◽  
pp. 282-283
Author(s):  
M.A. O'Keefe ◽  
Sumio Iijima
Keyword(s):  
Diffuse Scattering ◽  
Computing Time ◽  
Continuous Distribution ◽  
Sampling Interval ◽  
Reciprocal Space ◽  
Objective Lens ◽  
Lattice Images ◽  
Slice Method ◽  
Space Cell ◽  
Beam Lattice

We have extended the multi-slice method of computating many-beam lattice images of perfect crystals to calculations for imperfect crystals using the artificial superlattice approach. Electron waves scattered from faulted regions of crystals are distributed continuously in reciprocal space, and all these waves interact dynamically with each other to give diffuse scattering patterns.In the computation, this continuous distribution can be sampled only at a finite number of regularly spaced points in reciprocal space, and thus finer sampling gives an improved approximation. The larger cell also allows us to defocus the objective lens further before adjacent defect images overlap, producing spurious computational Fourier images. However, smaller cells allow us to sample the direct space cell more finely; since the two-dimensional arrays in our program are limited to 128X128 and the sampling interval shoud be less than 1/2Å (and preferably only 1/4Å), superlattice sizes are limited to 40 to 60Å. Apart from finding a compromis superlattice cell size, computing time must be conserved.

Analytic integration of contrast transfer functions

1988 ◽  
Vol 46 ◽  
pp. 822-823
Author(s):  
Peter Rez
Keyword(s):  
Wave Function ◽  
Transfer Function ◽  
Transfer Functions ◽  
Spherical Aberration ◽  
Continuous Distribution ◽  
Objective Lens ◽  
Direction Parallel ◽  
Scattering Angle ◽  
Analytic Integration ◽  
Image Position

In high resolution microscopy the image amplitude is given by the convolution of the specimen exit surface wave function and the microscope objective lens transfer function. This is usually done by multiplying the wave function and the transfer function in reciprocal space and integrating over the effective aperture. For very thin specimens the scattering can be represented by a weak phase object and the amplitude observed in the image plane is1where fe (Θ) is the electron scattering factor, r is a postition variable, Θ a scattering angle and x(Θ) the lens transfer function. x(Θ) is given by2where Cs is the objective lens spherical aberration coefficient, the wavelength, and f the defocus.We shall consider one dimensional scattering that might arise from a cross sectional specimen containing disordered planes of a heavy element stacked in a regular sequence among planes of lighter elements. In a direction parallel to the disordered planes there will be a continuous distribution of scattering angle.

Nuclear Electrons and Nuclear Structure

2018 ◽  
Author(s):  
Roger H. Stuewer
Keyword(s):  
Nuclear Structure ◽  
Beta Decay ◽  
Gamma Rays ◽  
Alpha Particle ◽  
Continuous Distribution ◽  
Alpha Particles ◽  
Light Nuclei ◽  
Coincidence Method ◽  
Wolfgang Pauli ◽  
Beta Particles

Serious contradictions to the existence of electrons in nuclei impinged in one way or another on the theory of beta decay and became acute when Charles Ellis and William Wooster proved, in an experimental tour de force in 1927, that beta particles are emitted from a radioactive nucleus with a continuous distribution of energies. Bohr concluded that energy is not conserved in the nucleus, an idea that Wolfgang Pauli vigorously opposed. Another puzzle arose in alpha-particle experiments. Walther Bothe and his co-workers used his coincidence method in 1928–30 and concluded that energetic gamma rays are produced when polonium alpha particles bombard beryllium and other light nuclei. That stimulated Frédéric Joliot and Irène Curie to carry out related experiments. These experimental results were thoroughly discussed at a conference that Enrico Fermi organized in Rome in October 1931, whose proceedings included the first publication of Pauli’s neutrino hypothesis.

Phosphate sorption by jurassic oolitic limestones

Geoderma ◽  
1975 ◽  
Vol 13 (3) ◽  
pp. 257-264 ◽  
Author(s):  
I.C.R. Holford ◽  
G.E.G. Mattingly
Keyword(s):  
Phosphate Sorption
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