Open AccessMesoporous silica prepared via a green route: a comparative study for the removal of crystal violet from wastewater
Author(s) -
Taiba Naseem,
Mirza Mahmood Baig,
Muhammad Farooq Warsi,
Rafaqat Hussain,
Philips O. Agboola,
Muhammad Waseem
Publication year - 2020
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/abd45d
Subject(s) - adsorption , crystal violet , materials science , mesoporous silica , chemical engineering , sodium silicate , langmuir adsorption model , mesoporous material , bagasse , monolayer , endothermic process , langmuir , nuclear chemistry , chemistry , organic chemistry , composite material , nanotechnology , catalysis , pulp and paper industry , medicine , pathology , engineering
In this present study, a wet chemical method with environmentally friendly and cost-effective bagasse ash is used to prepare the mesoporous silica structures. Significant amounts of silica (SiO 2 ) (∼75 percent) were measured in the bagasse ash as confirmed by x-ray fluorescence spectroscopy (XRF). The porous silica particles with uniform morphology showed a weight loss of ∼150 to ∼45%. The removal of crystal violet was performed with silica extracted from bagasse ash along with two other silica samples prepared from commercially available sodium silicate and TEOS for comparison purposes. The equilibrium adsorption data followed the Langmuir model for both linear and non-linear adsorption isotherm. The maximum monolayer capacity was found to be 26.53 mg/g. From the Langmuir isotherm, the value of ∆H is (SiO 2 (SS) = 0.83, SiO 2 (BA) = 5.19, and SiO 2 (TEOS) = 3.05), which indicates that the uptake of CV dye on mesoporous silica particles could be attributed to physical adsorption. The positive value of ∆H confirms that the adsorption is endothermic, and the positive value of ∆S indicates a certain structural modification and randomness increases in solid/liquid interface. The respective activation energy values for CV dye adsorption on mesoporous SiO 2 (SS), SiO 2 (BA), and SiO 2 (TEOS) are 0.83, 5.19, and 3.05 kJ mol −1 . All values are less than 8, showing that it is corresponding to physical adsorption. The findings further show that silica obtained from the bagasse ash is a cost-effective and equally effective adsorbent for the removal of crystal violet from an aqueous solution.