Bisacodyl removal from contaminated solution by synthesized mesoporous silica using experimental design method

Most of the medicinal compounds are entered no change into municipal wastewater and more than 90% of it remains in the wastewater. Mesoporous silica is known as thermally stable materials with controllable porosity and morphology. It is specified that these materials possess external and internal surfaces that can be selectively adsorbed the various compounds. In the present study, the synthesized mesoporous silica was studied to remove bisacodyl from polluted solutions. Mesoporous silica was synthesized by simple chemical method from tetraethylorthosilicate, ethanol (C2H5OH) and deionized water at 70 °C temperature. Characteristic of synthesized mesoporous silica was investigated by scanning electron microscopy. The effective parameters such as contact time, pH, adsorbate dose, and initial bisacodyl concentration were optimized for bisacodyl removal using 27 batch adsorption experiments according to design of experiment. The residual bisacodyl concentration was measured by UV-Vis spectrometer at the maximum wavelength of 580 nm. The statistical test and linear regression model were used by MINITAB 16 software for investigation of the main and interaction effects of each factor in the adsorption process. The ANOVA result showed 84% of bisacodyl was removed by synthesized mesoporous silica at optimum condition. The result of regression (R2 > 0.99) indicated that the adsorption process followed the Langmuir isotherm and second order kinetic at optimum conditions. The mesoporous silica is an efficient adsorbent for removing of bisacodyl from the polluted solutions so that it can be used for refining wastewaters containing medical compounds such as bisacodyl.