The biological quantitative reduction experimental research on aerobic excess sludge in papermaking wastewater

摘要

Titania nanotubes (TiO_2 NTs) working electrodes for hydrogen production by photoelectrocatalytic water splitting were synthesized by means of anodization method. The electrolytes were the mixtures of oxalic acid (H_2C_2O_4), ammonium fluoride (NH_4F), and sodium sulphate (VI) (Na_2SO_4) with different pHs. A constant dc power supply at 20 V was used as anodic voltage. The samples were annealed at 450°C for 2 hrs. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) were used to characterized TiO_2 NTs microstructure. TiO_2 NTs with diameter of 100 nm were obtained when pH 3 electrolyte consisting of 0.08 M oxalic acid, 0.5 wt% NH_4F, and 1.0 wt% Na_2SO_4 was used. Without external applied potential, the maximum photocurrent density was 2.8 mA/cm~2 under illumination of 100 mW/cm~2. Hydrogen was generated at an overall photo conversion efficiency of 3.4%.