The adsorption of direct fast black onto acid- thermal modified sepiolite was investigated. Batch adsorp- tion experiments were performed to evaluate the influences of experimental parameters such as initial dye conce...The adsorption of direct fast black onto acid- thermal modified sepiolite was investigated. Batch adsorp- tion experiments were performed to evaluate the influences of experimental parameters such as initial dye concentra- tion, initial solution pH and adsorbent dosage on the adsorption process. The three-factor and three-level Box- Behnken response surface methodology （RSM） was utilized for modeling and optimization of the adsorption conditions for direct fast black onto the acid-thermal modified sepiolite. The raw sepiolite was converted to acid-thermal modified sepiolite, and changes in the fourier transform infrared spectrum （FTIR） adsorption bands of the sample were noted at 3435 cm] and 1427 cm1. The zeolitic water disappeared and the purity of sepiolite was improved by acid-thermal modification. The decoloriza- tion rate of direct fast black adsorbed increased from 68.2% to 98.9% on acid-thermal modified sepiolite as the initial solution pH decreased from 10 to 2. When the adsorbent dosage reached to 2.5 g. L-1, 2.0 g. L-~, 1.5 g. I,I and 1.0g.L-1, the decolorization rate was 90.3%, 86.7%, 61.0% and 29.8%, respectively. When initial dye concen- tration increased from 25 to 200 rag. L-l, the decolorization rate decreased from 91.9% to 60.0%. The RSM results showed that the interaction between adsorbent dosage and pH to be a significant factor. The optimum conditions were as follows： the adsorbent dosage 1.99 g.L-1, pH 4.22, and reaction time 5.2 h. Under these conditions, the decolor- ization rate was 95.1%. The three dimensional fluores- cence spectra of direct fast black before and after treatment showed that the direct fast black was almost all adsorbed by the acid-thermal modified sepiolite.展开更多
文摘The adsorption of direct fast black onto acid- thermal modified sepiolite was investigated. Batch adsorp- tion experiments were performed to evaluate the influences of experimental parameters such as initial dye concentra- tion, initial solution pH and adsorbent dosage on the adsorption process. The three-factor and three-level Box- Behnken response surface methodology （RSM） was utilized for modeling and optimization of the adsorption conditions for direct fast black onto the acid-thermal modified sepiolite. The raw sepiolite was converted to acid-thermal modified sepiolite, and changes in the fourier transform infrared spectrum （FTIR） adsorption bands of the sample were noted at 3435 cm] and 1427 cm1. The zeolitic water disappeared and the purity of sepiolite was improved by acid-thermal modification. The decoloriza- tion rate of direct fast black adsorbed increased from 68.2% to 98.9% on acid-thermal modified sepiolite as the initial solution pH decreased from 10 to 2. When the adsorbent dosage reached to 2.5 g. L-1, 2.0 g. L-~, 1.5 g. I,I and 1.0g.L-1, the decolorization rate was 90.3%, 86.7%, 61.0% and 29.8%, respectively. When initial dye concen- tration increased from 25 to 200 rag. L-l, the decolorization rate decreased from 91.9% to 60.0%. The RSM results showed that the interaction between adsorbent dosage and pH to be a significant factor. The optimum conditions were as follows： the adsorbent dosage 1.99 g.L-1, pH 4.22, and reaction time 5.2 h. Under these conditions, the decolor- ization rate was 95.1%. The three dimensional fluores- cence spectra of direct fast black before and after treatment showed that the direct fast black was almost all adsorbed by the acid-thermal modified sepiolite.
