Characteristics of organobentonite prepared by microwave as a sorbent to organic contaminants in water

This paper put forward a microwave irradiation method to effectively prepare organbentonite, which aims to decrease time-consuming and energy-intensive in preparation of organobentonite by convention. The optimal conditions for preparing organobentonite by microwave (MOB) were studied. The mechanism of organobentonite prepared by microwave was proposed. Characteristics of MOB and organobentonite prepared by convention (COB) were compared in detail. An ideal amount of cetylpyridinium chloride (CPC) used for preparation of organobentonite was 1.0 times of cation exchange capacity (CEC) of bentonite. The optimal microwave irradiation time was 2 min. The preparation reaction time for organobentonite was decreased from several hours by convention to only a few minutes by microwave, which confirms that microwave method is very effectively for preparing organobentonite. XRD and atomic force microscopy (AFM) showed that the CPC moles have entered into interlayer spacing of bentonite. Comparing with natural bentonite, the intense endothermic peaks in differential thermal analysis (DTA)/Thermogravimetry (TG) curves of COB and MOB drifted to low temperature zone. Comparing with COB, the interlayer spacing of MOB was raised and the organic carbon content of MOB was increased 32.5% by microwave, which benefit to the sorption of organic compounds onto MOB from water.