Dye removal from aqueous solutions by silica microparticles
prepared in supercritical CO2
Ersin Başaran, Tuğba Alp, Özer Gök, Adnan Özcan and A. Safa Özcan
Anadolu University, Faculty of Science, Department of Chemistry, Yunusemre Campus,
26470, Eskisehir, Turkey
The contamination of the industrial wastewaters with synthetic dyes which are extensively
used in several industries such as textile, paper, automotive and dye production have caused
serious environmental problems. The dye containing wastewaters can create hazardous effects
on the living organisms because of carcinogenic, mutagenic, dermatitis and toxic [1]. The
disposal of these wastewaters is a very important issue. Several methods are available to
remove dye effluents from the wastewaters. In this manner there is a growing need to prepare
new efficient materials in environmentally friendly processes.
Supercritical fluids have been proposed as eco-friendly alternatives to traditional processes in
different industrial areas. Especially, CO2 is generally used as a supercritical fluid because of
its cheapness, non-toxicity, volatility and environmental impact at low critical parameters in
this technology. Supercritical CO2 has utilized preparation of silica microparticles as on
sphere shaped, controlled drug release agent, catalysis, column packing materials [2]. In
addition to these, supercritical fluid technologies have made possible to control the size
distribution of microparticles. The resulting microparticles can be used as an adsorbent for the
removal of pollutants from wastewaters.
In this study, silica microparticles prepared in supercritical CO2 were used to remove Acid
Blue 260 (AB260) dye from aqueous solutions as a function of pH and time. After removal
process, the functional groups of dye-loaded silica microparticles were determined by FTIR
analysis. SEM-EDX analysis and zeta potential measurements were also performed to
determine the characterization of microparticles. The results indicated that silica particles
obtained in this medium were in spherical shaped. The optimum conditions for the removal of
AB260 were also determined in success at pH=1.5 and 25 min.
Acknowledgement:
The Authors would like to acknowledge to Anadolu University Scientific Research Projects
(no 1306F256 and 1409F388) for financial support.
References:
[1] A. Bhatnagar, A.K. Jain J. Colloid Interface Sci., 2005, 281, 49-55.
[2] Alnaief, M., Smirnova, I., J. of Supercritical Fluids, 2011, 55, 1118-1123.