where [q.sub.e] (mg/g) and [q.sub.t] (mg/g) are the amounts of dye adsorbed per unit mass of adsorbate
at equilibrium and at time t, respectively, and [k.sub.1] ([min.sup.-1]) is the pseudo first-order rate constant.
The water molecules, which are displaced by the adsorbate
species, gain more translational energy than is lost by the adsorbate
ions, thus allowing the prevalence of randomness in the system .
The isosteric curves for different [C.sub.e] values and fixed amount of adsorbate
were obtained from the results of adsorption isotherms at different temperatures.
Where: [q.sub.eq] = adsorbed quantity (mg.[g.sup.-1]) for a given adsorbate
concentration (MB and phenol); [q.sub.m] = maximum adsorption capacity (mg.[g.sup.-1]); [C.sub.eq] = adsorbate
concentration after the equilibrium to be achieved (mg.[L.sup.-1]); and [K.sub.L] = Langmuir constant.
Adsorption capacity decreased with increased in adsorbent dose was due two factors: firstly due to concentration gradient which occurred between adsorbent and adsorbate
secondly due to intraparticle attraction which decreased the surface area of adsorbent.
where [q.sub.t] is the adsorbate
concentration at time t adsorbed by the adsorbent (mg.[g.sup.-1]) at equilibrium conditions, [C.sub.o] is the initial concentration of the compound (mg.[L.sup.-1]), [C.sub.e] is the equilibrium concentration in solution (mg.[L.sup.-1]), m is the mass of adsorbent (g), and V is the solution volume (L).
in which, [k.sub.YN] is the rate constant (1/min) and [tau] is the time required for 50% adsorbate
breakthrough (min), which can be obtained from the plot of ln[[C.sub.t]/([C.sub.0]-[C.sub.t])] versus t.
At low pH, adsorption of the adsorbate
will occur by a flat adsorbtion conformation and thus will make the particle adhere to each other and result in higher zeta potential as shown in the DAC case.
where [C.sub.e] is the adsorbate
equilibrium concentration (mg/L), [C.sub.0] is the adsorbate
initial concentration (mg/L), m is the mass of adsorbent (g), and V is the volume of solution used in adsorption (L).
To reduce the cost of using the adsorbent in practical applications, experiments were carried out to investigate the cycle times and to investigate the interaction between adsorbents and adsorbates
by X-ray photoelectron spectroscopy (XPS).
where [R.sub.L] is dimensionless constant and [c.sub.0] is the initial concentration of the adsorbate
. The values of [R.sub.L] between 0 and 1 indicate favourable adsorption.
There is a dramatic change in vapor permeability with relative humidity due to adsorbate
transport, capillary transport and liquid transport.
Freundlich isotherm exhibits an empirical relationship of adsorption of adsorbate
to the adsorbent.
As used in compressed-air systems, adsorption is where molecules of water (the adsorbate
) accumulate on the surface of a solid adsorbent medium.