Coupled Use of Modified Bentonite and Urea Hydrogen Peroxide to Degrade Paraxylene

The diffusion of odour caused by excavation disturbance during the restoration of pesticide sites adversely affects the surrounding environment. Therefore, it is essential to develop a new type of odour inhibitor that has both adsorption and oxidation functions and can effectively block odour. In this study, bentonite-modified cetyltrimethyl ammonium bromide (CTAB) was synthesised, and the structural changes of bentonite before and after modification were analysed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and other characterisation methods. Urea peroxide was loaded on modified bentonite (150C-Bent) by in situ synthesis method, and the preparation conditions were optimised. The effects of temperature, humidity and species on the adsorption behaviour and adsorption kinetics were studied by adsorption experiments. It is demonstrated that CTAB is embedded in bentonite through ion exchange, and the interlayer spacing expands from 1.42 to 3.11 nm. The optimal loading mass ratio of modified bentonite to urea peroxide was 1:1.5 and pH was 3. When the relative humidity is 54.3% and the temperature is 55 °C, the removal effect of paraxylene is the best; the optimal removal reached 82.4%. The adsorption behaviour of 1.5UHP-Bent conforms to the pseudo-second-order kinetic adsorption model. The adsorption pathway of paraxylene on UHP-Bent mainly includes partition effect and hydroxyl radical capture.