Motion of a spherical particle in a fluid forced vortex by DO M and DTM

In this study, coupled equations of the motion of a particle in a fluid forced vortex were investigated using the differential transformation method （DTM） with the Pad6 approximation and the differential quadrature method （DO_M）. The significant contribution of the work is the introduction of two new, fast and efficient solutions for a spherical particle in a forced vortex that are improvements over the previous numerical results in the literature. These methods represent approximations with a high degree of accuracy and minimal computational effort for studying the particle motion in a fluid forced vortex. In addition, the velocity profiles （angular and radial） and the position trajectory of a particle in a fluid forced vortex are described in the current study.     

Capture of phosphates in surface water by TiO2 nanoparticles under UV irradiation

The capture of orthophosphates and total phosphorus from the Pudong Canal river in the Pudong District of Shanghai by TiO2 nanoparticles is studied using a rotating photoreactor and the nano-TiO2 photocatalyst Degussa P25. The effects of UV irradiation intensity in a range of 20-74 mW/cm^2, the loading of the TiO2 nanoparticles in a range of 0.05-0.1 g/L, irradiation time up to 4 h, and pH values in a range of 2-10.5 on the capture efficiency are investigated. The results show that the capture of orthophosphates and total P are significantly enhanced by UV irradiation; at a loading of 0.1 g/L and an irradiation intensity above 36 mW/cm^2, orthophosphates and total phosphorus are rapidly captured by TiO2 nanoparticles, causing an observed reduction from 0.4 mg/L down to 0.02 mg/L. pH values in a range of 2-10.5 have little effect on the capture efficiency of orthophosphates and total phosphorus.     

In situ synthesis of CNTs/Fe-Ni/TiO2 nanocomposite by fluidized bed chemical vapor deposition and the synergistic effect in photocatalysis

Carbon nanotube(CNTs)/Fe-Ni/TiO_2 nanocomposite photocatalysts have been synthesized by an in situ fluidized bed chemical vapor deposition(FBCVD) method.The composite photocatalysts were characterized by XRD,Raman spectroscopy,BET,FESEM,TEM,UV-vis spectroscopy,and XPS.The results showed that the CNTs were grown in situ on the surface of TiO_2.Fe(lll) in TiO_2 showed no chemical changes in the growth of CNTs.Ni(Ⅱ) was partly reduced to metal Ni in the FBCVD process,and the metal Ni acted as a catalyst for the growth of CNTs.The photocatalytic activities of CNTs/Fe-Ni/TiO_2 decreased with the rise of the FBCVD reaction temperature.For the sample synthesized at low FBCVD temperature(500℃),more than 90% and nearly 50% of methylene blue were removed under UV irradiation in 180 min and under visible light irradiation in 300 min,respectively.The probable mechanism of synergistic enhancement of photocatalysis on the CNTs/Fe-Ni/TiO_2 nanocomposite is proposed.