Study On Removal Of Rhodamine 6G By Expanded Vermiculite Supported Nano-zero-valent Iron

Water pollution is one of the four major environmental pollution problems in China.Especially in the current situation of serious environmental pollution,it is the most prominent and most concerned.How to come up with effective and low-cost solutions is the problem that everyone is thinking about nowadays.Vermiculite is a kind of natural non-toxic layered mineral with special function.The water molecules between layers of vermiculite will rapidly vaporizes at high temperatures.At the same time,due to the great pressure generated by gasification,the interlayer structure of vermiculite can expand rapidly,which will result in the formation of expanded vermiculite with several times of volume.As a highly active reducing metal,nano zero-valent iron has unique advantages and good effects on the degradation of pollutants in water.In this paper,we used natural mineral materials by means of expansion as an carrier of zero-valent iron and studied the experiment about degredation of rhodamine 6G with the microwave synergy.The following results were obtained:Phase analysis and determination of vermiculite raw ore was performed by X-ray Diffraction,X-ray Fluorescence spectroscopy,Fourier infrared spectroscopy and other chemical analysis methods.We analyzed the thermal expansion performance of vermiculite raw ore in 100?,300?,500?,700? and 900? respectively.The result of research shows that the expansion temperature of vermiculite is positively correlated with the expansion rate of vermiculite.Vermiculite expansion rate has the best effect in 900?.The expanded vermiculite and acid modified vermiculite were prepared by sodium borohydride liquid phase reduction method.Scanning electron microscopy(SEM)showed that nano zero-valent iron was uniformly attached to the surface of expanded vermiculite.Rhodamine 6G was selected as the target pollutant.It was found that the composite material of nano zero-valent iron/expanded vermiculite had better removal effect than other materials,and the removal amount was up to 500mg/g.Under the microwave synergistic effect,the higher the microwave power and the lower the pH,the better the removal effect.Different loadings of zero-valent iron on expanded vermiculite have different removal effects on rhodamine 6G.The removal effect of 6G rhodamine on vermiculite modified by different acid concentration was different.