Environmental Engineering Reference
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the potential energy distribution with respect to distance is characterized by one
minimum located at the center of the pore or two symmetrical minima near the
pore walls. As a consequence, only one liquid layer mayexist in a pore. Set of
equations defines the conditions of existence of a thermodynamically stable layer
under the influence of an external potential field. The shape of isotherms depends
on the pore width and the variation of DFs with layer thickness. This dependence
should be continuous as it follows from the DFT and GCMC results. The behav-
ior of local isotherms in small pores completely agrees with the DFT or GCMC
results. The isotherms from IHK are continuous and they are shifted to the higher
values of the relative pressure with increasing of effective pore widths. Effec-
tive pore width is approximated as follows, In the case of pores, which are wide
enough (mesopores and some micropores), there are two local minima close to
the walls. As a result, in this case, two liquid layers mayexist in the same pore.
Once appeared in the pore, these two liquid layers increase with the reduced pres-
sure and the distance between them gradually decreases. As a consequence, these
two liquid like layers will coalesce into one liquid-like layer if a definite value of
the reduced pressure is reached and the mechanism of pore filling changes into
described above single layer. For each liquid-like layer (both layers are symmetri-
cal) the grand potential functional is defined as follows, The IHK method seems to
be a promising tool for the description of adsorption in porous solids. Since DFT
and GCMC methods are insufficient for the description of benzene adsorption
in micropores, IHKM seems to be the most advanced and promising procedure
of porosity characterization. Presented results show that the obtained pore size
distribution curves depend on the type of algorithm applied for the inverting of
global adsorption isotherm equation. In spite of the fact that REG leads to the
smoother PSD curves than constructed by us ASA algorithm, it can sometimes
generate negative parts of distribution what is without physical meaning. On the
other hand, the PSD of real heterogeneous solids is rather smooth and continu-
ous than discreet, so regularization method used in the REG algorithm seems to
be natural choice (there is necessary to take under considerations the smoothing
effect on the estimated PSD). Thus, this work can state that such two algorithms
in connection with intuition of researchers may be successfully applied for the
proper solution of the considered ill-posed problem. The results of IHK as well as
ND methods show small amount of porosity in carbon blacks applied as reference
materials for the construction of as plots. The comparison of the results from IHK
and ND for microporous carbons leads to the conclusion about similarity of the
both methods [133].
Many researchers represented molecular models for adsorption of water on
ACs and description a comparison between simulation and experimental work
results. The activated carbon is modeled as being made up of non-interconnected
slit pores having a distribution of pore widths given by the experimentally de-
termined PSD. The PSD from experiment gives information on the effective, or
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