Journal of Nanotechnology

Research Article

Separation of Spherical Nanosilica from Agricultural Wastes in Vietnam via Ultrasonic-Assisted Precipitation and Application for Effective Removal of Methylene Blue from Aqueous Solution

Parameters of pseudo-first- and second-order kinetic studies on MB adsorption of BA-SiO₂, RHA-SiO₂, and pure-SiO₂ at different initial MB contents.


MB initial concentrations (mg·L⁻¹)			10	20	30	40	50

Pseudo-first-order kinetic model	q_e(mo) (mg·g⁻¹)	BA-SiO₂	2.07	4.13	7.01	8.73	10.74
		RHA-SiO₂	3.55	7.92	11.26	10.17	14.47
		Pure-SiO₂	3.56	8.14	17.45	22.37	15.18
	k	BA-SiO₂	0.0448	0.0434	0.0542	0.049	0.0443
		RHA-SiO₂	0.0491	0.0579	0.0459	0.0456	0.0492
		Pure-SiO₂	0.0584	0.0505	0.0661	0.0677	0.0485
	R²	BA-SiO₂	0.982	0.991	0.981	0.947	0.931
		RHA-SiO₂	0.989	0.974	0.988	0.998	0.991
		Pure-SiO₂	0.998	0.972	0.888	0.940	0.986

Pseudo-second-order kinetic model	q_e(mo) (mg·g⁻¹)	BA-SiO₂	2.84	5.20	6.95	9.44	11.03
		RHA-SiO₂	4.20	7.28	10.63	12.69	14.99
		Pure-SiO₂	4.17	8.04	11.38	15.04	16.78
	k	BA-SiO₂	0.0372	0.0137	0.0108	0.0086	0.0052
		RHA-SiO₂	0.0228	0.0104	0.0041	0.0070	0.0046
		Pure-SiO₂	0.0332	0.0082	0.0046	0.0043	0.0039
	R²	BA-SiO₂	0.997	0.998	0.996	0.996	0.996
		RHA-SiO₂	0.997	0.996	0.992	0.998	0.997
		Pure-SiO₂	0.997	0.995	0.989	0.989	0.996

q_e(ex) (mg·g⁻¹)		BA-SiO₂	2.62	4.59	6.20	8.59	9.63
		RHA-SiO₂	3.86	6.55	8.90	11.63	13.36
		Pure-SiO₂	3.91	7.10	9.68	13.28	14.72