Different Modified Expanded Perlite Preparation And Removal Of Organic Pollutants In The Environment

Combining the lightweigh and porous characteristics of expanded perlite with the surfactant adsorption efficiency for organic pollutants of TiO₂ photocatalytic degradation, different environmental remediation materials were prepared by using surfactants (cationic surfactant CTMAB, anionic surfactant CPB and non-ionic surfactant TX-100) and/or TiO₂ to surface-modify expanded perlite (EP). Photocatalytic degradation of organic pollutants, such as phenol, p-nitrophenol and aniline, in polluted environment by these materials, and relevant factors affecting removal effects were studied. The effect of CTMAB/TiO₂ surface-modified EP on remediation to phenol contaminated soil was also carried out. And the structure characterizations of these materials were carried out by XRD and SEM to study the adsorption of organic pollutants and the degradation mechanism of the modified EP.The main results were shown as follows:(1) Structural characteristic had been studied through XRD and SEM. Anatase TiO₂ were prepared and loaded successfully to EP; TiO₂ or surfactant may enter into the space of expanded perlite.(2) EP had little ability to remove methyl orang in water, while EP modified with surfactant and/or TiO₂ could remove methyl orang significantly. The removal ability of TiO₂/CTMAB-EP was significantly higher than that of TiO₂/CPB-EP and TiO₂/TX-100-EP. pH had no significant effect to photocatalytic degradation of P-Nitrophenol by TiO₂, but produced a significant effect on adsorption of P-Nitrophenol by CTMAB.(3) Compared with CTMAB-EP or TiO₂-EP, TiO₂/CTMAB-EP had significantly higher removal rate of p-nitrophenol in water. The highest removal rate of P-Nitrophenol by TiO₂/CTMAB-EP treatment occurred at pH 8. Removal effects of the materials were influenced by dosage of material, shaking time, initial concentration of P-nitrophenol in water and pH. Under the alkaline pH condition, the removal rate of phenol, aniline and p-nitrophenol by CTMAB/TiO₂ modified expanded perlite was higher than that under acid or neutral conditions.(4) TiO₂/CTMAB-EP had ability to remove phenol from contaminated soil. Results from this study indicated that EP modified with surfactant and TiO₂ can be used as a new kind of environmental remediation materials for the restoration of organic contaminated soil and water.