The injurious effect of hydrogen peroxide (H(2)O(2)) on renal epithelial cells of the African green monkey (Vero cells) and the difference in the modulation of Vero cells on crystal growth of calcium oxalate (CaOxa) before and after injury were investigated. The degree of injury of Vero cells was proportional to the concentration and action time of H(2)O(2). After the cells had been injured, the released amount of malonaldehyde in the culture medium increased, the superoxide dismutase activity decreased, the expression quantity of osteopontin on the surface of Vero cells increased significantly, the zeta potential became more negative, and the amount of CaOxa crystals adhering to cells increased. The CaOxa crystals induced by the cells in the control group were round and blunt; however, those induced by the injured cells had irregular shapes with sharp edges and corners. As the crystallization time increased from 6 to 24 h, the size of the crystals induced by the injured cells increased accordingly, whereas that of crystals induced by the control cells did not increase significantly. The injured cells could promote the growth of CaOxa crystals and their adhesion to the cells; thus, the formation of CaOxa stones was promoted. The cells in the control group could also be injured after being incubated with supersaturated CaOxa solution for a long time, which promoted the crystallization of CaOxa. The results suggest that the retention of supersaturated CaOxa solution or CaOxa crystals in the urinary tract for a long time is a risk factor for the formation of kidney stones.

No abstract

The palm oil industry generated thick brownish liquid waste known as POME (palm oil mill effluent). POME is one of the wastes that can seriously threaten the survival of aquatic life if discharged untreated. In this study, efficient photocatalytic degradation of POME by CuFe2O4 decorated on BiOCl (BiOCl/CuFe2O4) was reported. The Z-scheme BiOCl/CuFe2O4 composite was successfully fabricated via a precipitation-hydrothermal method. The fourier-transform infrared spectroscopy (FTIR) result clearly displayed the presence of BiOCl and CuFe2O4 in the composite photocatalyst. Compared to pure BiOCl, the composite photocatalyst demonstrated a redshift in the wavelength absorption and great visible light absorbing ability. The photodegradation experiments indicated that the BiOCl/CuFe2O4 demonstrated exceptional POME degradation and decolourization efficiencies of 60% and 68%, respectively after 720 min illumination when compared to the single-phase component photocatalysts. The photocatalytic enhancement of BiOCl/CuFe2O4 can be attributed to the efficient charge carrier separation via the Z-scheme heterojunction.