Q2. What is the third part of the linear fit of intra-particle diffusion model?
The third part is the final equilibrium stage in which the intra-particle diffusion slows down ascribed to the low concentration of residual phosphate in the solution [48, 49].
Q3. What are the three important thermodynamic parameters used to determine the spontaneous nature of the processes?
In their study, three important thermodynamic parameters, ∆G°, ∆H° and ∆S°, are taken into account to determine the spontaneous nature of the processes.
Q4. What is the phosphate uptake capacity of the modified EV adsorbent?
the phosphate uptake capacities increase from La0.63EV to La10EV; which is attributed to the greater La loadings in the resulting adsorbents by increasing La/EV ratios in the initial synthetic solution.
Q5. How many g of EV was firstly dispersed in 200.0 mL?
8.0 g of EV was firstly dispersed in 200.0 mL of DI water under continuously stirring for 2 h to obtain a uniform EV aqueous mixture.
Q6. How many types of clays were used in Yuan’s work?
For instance, in Yuan’s work, the phosphate adsorption ratios of fourteen types of LaCl3-modified clays, including argil, pumice, attapulgite, kaolinite, etc., ranged from 93 % to 99 %, which were around 6 % – 37 % greater than those of unmodified clays [18].
Q7. How many mL of isopropanol solution was added to the EV?
200.0 mL of isopropanol solution consisting of a certain amount of La(NO3)3·6H2O (Tianjin Daomao reagent factory) was slowly added into the prepared EV aqueous mixture.
Q8. What is the effect of La(OH)3 nanorods on the surface of EV?
the deposition of La(OH)3 nanorods on the surfaces of EV may contribute to the evident increase of external superficial area in La5EV.
Q9. How was the effect of coexisting anions on the phosphate removal capacity?
To study the effect of coexisting anions on the phosphate removal capacities, 0.050 g of the adsorbent was added into the phosphate solution containing 0.01 M and 0.10 M coexisting ions, which were prepared by dissolving sodium salt forms of F−, Cl−, NO3 −, SO4 2−, and CO3 2− into 20 mg P/L phosphate solution.
Q10. How does the phosphate adsorption of La5EV affect the ad?
As seen, the phosphate adsorption capacity strongly depends on the initial P concentration of solution; that the adsorption capacity of La5EV recorded at 48 h increases from 20.7 mg P/g in 20 mg P /L solution to 70.3 mg P/g in 80 mg P/L solution.
Q11. Why is the ring pattern of La(OH)3 in the EV?
The SAED pattern of La(OH)3 (the inset of Fig. 3d) indicates the ring pattern, which is due to the polycrystalline nature of La(OH)3 nanorods formed on EV.
Q12. What is the mechanism to explain the high phosphate adsorption at low pH?
The other possible mechanism to explain the high phosphate adsorption at a low pH value is that the presence of a large number of H+ ions in the solution may induce the formation of protonated vermiculite20surfaces, favoring the electrostatic attraction to the phosphate species H2PO4 −; herein an example of reaction is shown.
Q13. How many g of phosphate solution was added to the sample?
Adsorption kinetic experiments were conducted as follows: 0.20 g of the adsorbent was added in 200.0 mL of phosphate solution with initial concentrations of 20, 50 and 80 mg P/L, respectively.
Q14. How does the pH of La5EV change after 12 h?
After adding La5EV, the pH value gradually increases to 10.23 after 12 h, when the equilibrium is reached in the solution with an initial phosphate concentration of 20 mg P/L according to the finding in their kinetic study (Fig. 4a); and maintains at 10.23 for another 36 h.
Q15. What is the adsorption capacity of the fabricated La5EV?
By taking into account of ~ 88.5 % desorption ratio of spent La5EV within 24 h (Fig. S3), the decreasing adsorption capability observed in the adsorption-desorption cycle studies may be attributed to the incomplete desorption of adsorbed phosphate during regeneration.
Q16. What is the effect of adding coexisting anions on the phosphate ad?
There is a negligible effect on qe of La5EV by adding 0.01 M coexisting anions in the solution, suggesting that La5EV possess a high selective adsorption capacity to phosphate anions.
Q17. How much phosphate adsorption capacity is the unmodified EV?
the unmodified EV exhibits the phosphate adsorption capacity of approximately 2.15 mg P/g after 12 h in the solution with an initial concentration of 20 mg P/L.
Q18. How much phosphate was removed from the vesuvianite?
Li and co-workers reported that the adsorption capacity of the vesuvianite modified with a La/Ves mass ratio of 0.16 (1.30 mg P/g) was around 3.6 times greater than that of undoped vesuvianite (0.28 mg P/g) [17].
Q19. What is the phosphate removal performance of adsorbent in synthetic secondary treated wastewater?
The phosphate removal performance of adsorbent in synthetic secondary treated wastewater was also studied, which was prepared according to the reference [35], with the respective carbon (as COD), nitrogen (N), and phosphate (P) concentrations of 100 mg/L, 12 mg/L, and 2 mg/L, respectively.