A Review on Advances in the Use of Raw and Modified Agricultural Lignocellulosic Residues in Mono- and Multicomponent Continuous Adsorption of Inorganic Pollutants for Upscaling Technologies

. 2025 Mar 31;17(7):953. doi: 10.3390/polym17070953

$A^{'}$	Area of the “desorption curve peak” (min)
A, B	Fitting parameters (min⁻²)
ANN	Artificial neural network
ANFIS	Artificial neural–fuzzy inference system
AIC	Akaike Information Criterion
BDST	Bed Depth Service Time
C₀	Initial adsorbate concentration (mmol L⁻¹ or mg L⁻¹)
C	Column effluent concentration at time t (mmol L⁻¹ or mg L⁻¹)
C_e	Equilibrium concentration (mmol L⁻¹ or mg L⁻¹)
D	Adsorption column diameter (cm)
$D_{a x}$	Axial dispersion coefficient (cm² min⁻¹)
E_ads	Adsorption efficiency (%)
E_des	Desorption efficiency (%)
E_re-ads	Re-adsorption efficiency (%)
GA	Genetic algorithm
H_b	Column bed height (cm)
H_unb	Unused bed height (cm)
HSAB	Hard and Soft Acids and Bases
HSDM	Homogeneous Surface Diffusion Model
IAST	Ideal Adsorbed Solution Theory
k_BA	Bohart–Adams rate constant (L mg⁻¹ min⁻¹ or L mmol⁻¹ min⁻¹)
K_sp	Solubility product constant
k_Th	Thomas rate constant (L mg⁻¹ min⁻¹ or L mmol⁻¹ min⁻¹)
k_YN	Yoon–Nelson rate constant (min⁻¹)
JCR	Journal citation reports
L	Bed depth (cm)
LDF	Linear Driving Force
M	Mass of the adsorbent in the column (mg or g)
N₀	Adsorption capacity of the adsorbent per unit volume of the bed (mg L⁻¹ or mmol L⁻¹)
NC	Number of citations
MTZ	Mass transfer zone (cm)
P	Particle size (μm)
pK_f	Complex formation constants
PSO	Particle swarm optimization
q₀	Maximum adsorption capacity of the adsorbent (mg g⁻¹ or mmol g⁻¹)
Q	Volumetric flow rate (L min⁻¹)
Q_e	Solid loading per unit weight of adsorbent at equilibrium condition (mg g⁻¹ or mmol g⁻¹)
Q_e,est	Estimated adsorption capacity (mg g⁻¹ or mmol g⁻¹)
Q_e,exp	Experimental adsorption capacity (mg g⁻¹ or mmol g⁻¹)
Q_mono	Solid loading per unit weight of adsorbent in a monocomponent system (mg g⁻¹ or mmol g⁻¹)
Q_multi	Solid loading per unit weight of adsorbent in a multicomponent system (mg g⁻¹ or mmol g⁻¹)
RAST	Real Adsorbed Solution Theory
R²	Coefficient of determination
R²_adj	Adjusted coefficient of determination
T	Temperature (ºC)
t	Time (min)
t_b	Breakthrough time (min)
$t_{c}^{'}$	Center of the “desorption curve peak” (min)
t_s	Saturation time (min)
TRL	Technology readiness level
u	Linear velocity of the fluid through the column (m s⁻¹ or cm min⁻¹)
w	Weight of adsorbent (mg or g)
Z	Distance along column length (cm)
$Z_{0}^{'}$	Offset (equal to $\frac{C_{e}}{C_{0}}$ (1.0))
Z_e	Effective use of the bed (%)
$w^{'}$	Half width of the “desorption curve peak”(min)
α	Fitting parameter for InOrdinatio equation
β	External mass transfer coefficient (min⁻¹)
β_L	Stability constant
ƞ	Absolute hardness
χ²	Chi-square
χ²_red	Reduced chi-square
$ε$	Bed porosity
$ε_{b}$	Empty fraction of the column
$v_{F}$	Interstitial velocity (cm min⁻¹)
ρ_p	Particle density (g mL⁻¹)