Open AccessAdsorptive Removal of Malachite Green from Model Aqueous Solutions by Chemically Modified Waste Green Tea Biomass
Author(s) -
Cerasella Indolean,
Silvia Burcă,
Andrada Măicăneanu
Publication year - 2017
Publication title -
acta chimica slovenica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.289
H-Index - 46
eISSN - 1580-3155
pISSN - 1318-0207
DOI - 10.17344/acsi.2017.3271
Subject(s) - malachite green , adsorption , chemistry , aqueous solution , endothermic process , biomass (ecology) , nuclear chemistry , fourier transform infrared spectroscopy , tartaric acid , organic chemistry , chemical engineering , citric acid , agronomy , engineering , biology
The adsorption of malachite green (MG) from aqueous solution by waste green tea (WGT) biomass was investigated. A series of experiments in batch conditions were conducted in order to assess the MG removal on WGT, following adsorbent quantity and temperature influences. Maximum removal efficiency for untreated WGT was 89% (4 g biomass, 100 mL solution of 94 mg/L, 316 K). It was found that the adsorption of MG increased by increasing temperature from 296 to 316 K. Thermodynamic parameters (ΔH°, ΔS°, ΔG°) were calculated, and indicated that dye adsorption onto the studied biomass was endothermic and non-spontaneous. Six chemical treatments were tested (four acidic - H3PO4, H2SO4, HCl, and tartaric acid, one oxidant - H2O2, and one basic - NaOH) in order to study the chemical groups responsible for MG adsorption onto WGT biomass. The alkali and acidic treatments led to an increase of adsorption efficiency up to 92% and 95% (H2SO4) respectively. The FTIR spectroscopy results emphasized the modifications of the biomass surface and how these are influencing the adsorption process.