Constants and Critical Values of IAPWS-95 (IAPWS 1995) Quantity Symbol Value Universal molar gas constant [[bar.R].sup.95] 8.314371 kJ/(kmol*K) Specific gas constant [R.sup.95] 0.46151805 kJ/(kg*K) Molar mass [M.sup.95] 18.015268 kg/kmol Critical mass density [[rho].sub.c] 322 kg/[m.sup.3] Critical temperature [T.sub.c] 647.096 K Critical pressure [p.sub.c] 22.064 MPa All thermodynamic properties for water and steam can be derived from Equation 2 by using the appropriate combinations of the ideal-gas part [alpha][degrees] and the residual part [[alpha].sup.r] of the dimensionless Helmholtz energy and their derivatives.

Constants and Critical Values of IAPWS-IF97 (IAPWS 2007) Quantity Symbol Value Universal molar gas constant [[bar.R].sup.97] 8.314510 kJ/(kmol*K) Specific gas constant [R.sup.97] 0.461526 kJ/(kg*K) Molar mass [M.sup.97] 18.015257 kg/kmol Critical mass density [[rho].sub.c] 322.0 kg/[m.sup.3] Critical temperature [T.sub.c] 647.096 K Critical pressure [p.sub.c] 22.064 MPa Liquid-Water Region 1.

Constants and Values Used in IAPWS-06 (IAPWS 2006; Feistel and Wagner 2006) Quantity Symbol Value Universal molar gas constant [[bar.R].sup.06] 8.314472 kJ/(kmol*K) Specific gas constant [R.sup.06] 0.46152364 kJ/(kg*K) Molar mass [M.sup.06] 18.015268 kg/kmol Triple-point temperature [T.sub.t] 273.16 K Triple-point pressure [p.sub.t] 0.611657 kPa All thermodynamic properties for ice can be derived from Equation 5 by using the appropriate combinations of the Gibbs energy g and its derivatives.

where p is the total pressure of moist air, [bar.v] is the molar mixture volume, [bar.R] is the universal molar gas constant given in Table 5, [B.sub.m] is the second molar virial mixing coefficient, and [C.sub.m] is the third molar virial mixing coefficient.

where [n'.sub.i] is the number of moles of gas initially in the inlet volume, [n'.sub.i] is the number of moles of gas initially in the outlet volume, [n.sub.i] is the number of moles of gas leaving the inlet volume, [n.sub.o] is the number of moles of gas entering in the outlet volume, R is the

molar gas constant, and T is the gas absolute temperature.

where, [theta] indicates the fraction of surface coverage, [DELTA]H[degrees] is the enthalpy of adsorption, b is Langmuir constant and R is the molar gas constant. For a particular amount adsorbed (70 mg/g), the change of equilibrium concentration with temperature has been calculated from Figure 5.

where [q.sub.e] is the amount adsorbed of dye per unit weight of adsorbent (mol/g), [q.sub.m] the maximum adsorption capacity (mol/g), [C.sub.e] is the equilibrium concentration of dye in aqueous solution (mol/L), R is the molar gas constant and T is the temperature (K), [beta] is the activity coefficient related to the mean free energy of adsorption ([mol.sup.2]/[kJ.sup.2]) and [epsilon] is the Polanyi potential ([epsilon] = RT ln(1 + 1/[C.sub.e]) [15].