The Effect of Single, Binary and Ternary Anions of Chloride, Carbonate and Phosphate on the Release of 2,4-Dichlorophenoxyacetate Intercalated into the Zn–Al-layered Double Hydroxide Nanohybrid

Table 1 Basal spacing and elemental analysis of Zn–Al-LDH (ZAN) and its nanohybrid with 2,4-D (ZANDI), the rate constants and correlation coefficients obtained from pseudo-second order fitting of the release of 2,4-D into single, binary and ternary aqueous systems

Sample	Basal spacing (Å)	Zn/Al ratio	(N)/C (%)	2,4-D (% w/w)^a
ZAN	8.9	3.8	(2.8)	–
ZANDI	20.1	4.0	14.7	33.9

Aqueous solution (0.05 M)	Maximum release (%)	Maximum release time (min)	Zeroth order	First order	Parabolic diffusion	Pseudo-second order
Aqueous solution (0.05 M)	Maximum release (%)	Maximum release time (min)	r ²			r ²	k(mg L s⁻¹)^b	t_½(min)^c
Cl	25	4,273	0.779	0.811	0.914	0.996	0.000027	498
CO₃	99	3,828	0.372	0.966	0.529	1.000	0.000033	107
PO₄	93	701	0.427	0.511	0.616	0.997	0.000083	45
Cl-CO₃	80	1,744	0.623	0.697	0.797	0.990	0.000024	167
Cl-PO₄	88	840	0.378	0.445	0.567	0.999	0.000068	58
CO₃-PO₄	90	725	0.539	0.586	0.715	0.986	0.000035	104
Cl-CO₃-PO₄	88	270	0.564	0.586	0.774	0.982	0.00004	91