Table 7.

Evaluation of inflection point

Service cycle No	tI h	t50 h	t50-tI	μmax, h−1	τ h	EBCT min
1st	83.140	83.33	0.190	0.034	76.90	13.565
2nd	92.996	93.91	0.914	0.037	91.38	13.565
3rd	102.683	102.80	0.117	0.049	97.28	13.565
4th	52.801	53.22	0.419	0.088	52.97	13.565
5th	67.779	67.81	0.031	0.068	92.71	9.043
6th	63.171	63.62	0.449	0.062	71.37	9.043
7th	31.410	31.64	0.230	0.117	31.37	4.522
8th	15.020	15.38	0.360	0.118	16.42	2.261
9th	9.524	10.32	0.796	0.123	17.40	1.507

t₅₀ – the time at inflection point (h), t₅₀ – the time required for 50% of zinc breakthrough (h), τ—the time required for 50% of zinc breakthrough calculated from experimental condition by Eq. (16), μ_max – the maximum specific breakthrough rate (h⁻¹), EBCT – empty bed contact time (min), $\text{EBCT}=H/\nu =H/\left(Q/A\right)$