Decolorization of reactive brilliant red K-2BP by white rot fungus under sterile and non-sterile conditions

Almost all the studies both domestic and international using white rot fungus for dye wastewater treatment are performed under sterile conditions. However, it is obviously unpractical that wastewater with dyes is treated under sterile conditions. A feasible study was made for using white rot fungus Phanerochaete chrysosporium to degrade reactive brilliant red K-2BP dye under non-sterile conditions. The results showed that there was no decolorizing effect under non-sterile condition if white rot fungus was incubated under non-sterile condition, and the decolorization was always near to 0% during decolorizing test for 3 d; in the meantime, a lot of yeast funguses were found in liquid medium when white rot fungus was incubated under non-sterile conditions; however, if white rot fungus was incubated under sterile condition firstly, its decolorization was above 90% under non-sterile condition, which was similar to that of sterile condition. So we point out that the treating process for wastewater with dyes should be divided into two stages. The first stage is that white rot fungus should be incubated under sterile conditions, and the second stage is that reactive brilliant red K-2BP is decolorized under non-sterile conditions. The method not only save the operation cost which decolorizing reactive brilliant red K-2BP under sterile condition, but also provide the feasibility for using white rot fungus to degrade wastewater with dyes under non-sterile conditions.

Preparation of TiO_2/activated carbon with Fe ions doping photocatalyst and its application to photocatalytic degradation of reactive brilliant red K2G

Titanium dioxide coated on activated carbon(AC) with Fe ions doping(Fe-TiO2/AC) composite was prepared by an improved sol-gel method.The photocatalytic activities were tested by photocatalytic degradation of reactive brilliant red K2G in solution.The results show that in comparison with the agglomeration of pure TiO2,the TiO2 nanoparticles are well dispersed in the AC matrix,of which sizes are decreased with Fe ions doping.Additionally,the iron species on TiO2 of composite are Fe2O3 and FeO,which do not affect the crystalline structures of TiO2 nanoparticles.The AC matrix and iron doping content influence the fluorescence intensity of composite due to their effects on recombination probability of hole-electron pairs.Compared with TiO2,0.3% Fe-TiO2,TiO2/AC,0.5% Fe-TiO2/AC and 0.1% Fe-TiO2/AC,the 0.3% Fe-TiO2/AC shows the highest photoactivity with the complete mineralization of K2G for finite time due to the optimum Fe ions content and AC matrix.Furthermore,the kinetic constant(k=0.0229 min-1) of 0.3% Fe-TiO2/AC composite is more than the sum of both TiO2/AC(0.0154 min-1) and 0.3% Fe-TiO2(0.0057 min-1) because coexistence of the AC and Fe ions has an enlarging effect on improving the photoactivity of TiO2.

A simple and cheap method for preparation of coupled ZrO_(2)/ZnO with high photocatalytic activities

The objective of this study was to prepare a new photocatalyst with high activities for degradation of organic pollutants.Coupled ZrO_(2)/ZnO photocatalyst was prepared with a simple precipitation method with cheap raw materials zinc acetate and zirconium oxychloride,and was character-ized by X-ray diffraction(XRD)and transmission electron microscopy(TEM).Reactive brilliant red X-3B was used as a model compound to investigate the photocatalytic activity of synthesized catalysts in water under 254 nm UV irradia-tion.Results show that the optimal calcination temperature and coupling molar ratio of Zr were 350°C and 2.5%,respec-tively.At the calcination temperature of 350°C,ZrO_(2) was dispersed on the surface of hexagonal ZnO in the form of amorphous clusters.The particle size of ZrO_(2)/ZnO decreased with the decrease of calcination temperature and the increase of Zr coupling amount.ZrO_(2)/ZnO has better photocatalytic activity for degradation of reactive brilliant red(RBR)X-3B than pure ZnO and P25-TiO_(2).