Preparation Of Nano-NiO And Its Photocatalytic Degradation Of AcidRed-G

Treating organic wastewater is an important task with practical value. On the basis of surveying photocatalytic oxidation technology and organic dyestuff wastewater controlling approaches inside and outside country, organic wastewater treated by photocatalytic oxidation technology of semiconductor was studied systematically in this paper. The study showed that the technology was in possession of the prominent virtues, such as high treatment efficiency, simple processing equipment, operation conditions controlled easily, organic pollutants degraded non-selectively, no secondary pollution, etc. So it can provide new thoughts and pathways for industrialization treatment of organic wastewater and will be endowed with extensive application prospect in the organic wastewater treatment. In this thesis, three methods were studied on improving the efficiency of photodegradation:(1) Nano-meter NiO particles were prepared by method of precipitation and were characterized by X-ray diffraction, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results of X-ray diffraction and scanning electron microscope (SEM) showed that the average diameter of the particles ranged from 11.5nm to 26.9nm, and the majority crystal structure was ball.(2) Acid red-G and direct bordeaux were selected as representative organic dyestuff to simulate organic wastewater which was treated by photocatalytic oxidation using the nano-NiO as photocatalyst. Factors affecting photocatalytic oxidation reaction were studied in details, such as catalyst amount, UV irradiation time, initial concentration of solution, PH value, etc. And the approaches to improve photocatalyst activity of NiO were also investigated from the temperature and time of heat treatment. In addition, the mechanism ofphotocatalytic oxidation technology degrading organic dyestuff was discussed in this paper. The photocatalytic degradation experiments of acid red-G showed that, high photocatalytic reactivity of NiO was achieved at 400 ℃ for 2h, the catalyst was active in acid condition, the photocatalytic activity was inverse relationship with initial concentration of solution, and the better values for photocatalytic degradation of dosages of catalyst and UV irradiation time existed.(3) The kinetics of photocatalytic oxidation reaction for dyes was studied. The result showed that the reaction was first-order and the velocity of reaction was coincident with multiphase catalytic kinetic equation: Langmuir -Hinshelwood equation.