| Printing and dyeing wastewater is the major water pollution in China,which has caused people's concern.Nano zero-valent iron(n ZVI)is widely used in the field of environmental remediation because of its strong reactivity.However,the n ZVI is easily oxidized in air and easy to agglomerate,which greatly reduces its reactivity.In order to inhibit the oxidation of n ZVI and improve its reactivity,a mineral loaded n ZVI composite material supported by montmorillonite-based,kaolinite and sepiolite mineral supposed n ZVI composite material were prepared by using mineral carrier as carrier,and the removal of Rhodamine 6G(Rh 6G)in water under microwave irradiation was carried out.The main results are as follows:(1)Using montmorillonite(MMT),kaolinite(K)and sepiolite(S)as the supporter,a series of mineral-loaded n ZVI was prepared by the liquid-phase reduction method with sodium borohydride,which effectively solved the problem of the agglomeration of n ZVI and slowed down the oxidation of n ZVI.(2)The initial pH value,initial concentration and different materials on the removal of Rh 6G were investigated.It has been found that the supported zero-valent iron has better removal effect on Rh 6G and stronger antioxidant capacity than that of ordinary n ZVI and individual minerals,supported zero-valent iron has better removal effect on Rh 6G and stronger antioxidant capacity;The maximum removal amount of Rh 6G by n ZVI/MMT,n ZVI/K and n ZVI/S is 500 mg/g,110 mg/g and 310 mg/g respectively;The removal rate decreases with the increasing increase of p H,and increases with the increase of microwave power.(3)The reasons for the different removal amount of Rhodamine 6G by different mineral loadings of n ZVI were investigated.By observing the morphology,comparing the mineral's Zeta potential and the specific surface area of the loaded n ZVI,we find that all of these factors have an effect on the removal of Rhodamine 6G due to the different structures of different mineral. |
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