Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4980958 | Process Safety and Environmental Protection | 2016 | 44 Pages |
Abstract
This investigation emphasized the optimum preparation conditions for the chemical modification of eucalyptus sawdust biochar as a potential biosorbent to promote the removal of nitroimidazoles from aqueous solutions. By ANOVA for central composite design of response surface methodology, we found the activation temperature and impregnation ratio of 85% H3PO4 to sawdust as the significant factors for maximizing the adsorption capacity of metronidazole. Optimum activation temperature, impregnation ratio, and activation time were 500 °C, 0.62, and 90 min, respectively. The Brunauer-Emmett-Teller surface area and total pore volume increased from 32.80 m2 gâ1 to 882.04 m2 gâ1 and 0.01829 cm3 gâ1 to 0.4316 cm3 gâ1 after H3PO4 activation, respectively. The removal efficiencies using biochar prepared at optimum conditions were 97.1% and 96.4% for metronidazole and dimetridazole at 20 mg Lâ1 concentration and 1.0 g Lâ1 biochar dosage within 2 h. The adsorption process was described well by pseudo-second-order model, and solute transfer was controlled by both boundary-layer and intraparticle diffusion. Thermodynamic study revealed that the adsorption process was spontaneous and exothermic. The Freundlich model presented better a fit for the adsorption equilibrium. The maximum adsorption capacities for metronidazole and dimetridazole were 167.5 and 200 mg gâ1, respectively.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Chemical Health and Safety
Authors
Shungang Wan, Zulin Hua, Lei Sun, Xue Bai, Lu Liang,