Preparation Of NiO/KA₂Nb₃O₁₀(A=Ca, Sr) And Study Of Its Photocatalytic Degradation Of Acid Red 3B

Treatment of organic wastewater is an important task with practical value. On the basis of surveying photocatalytic oxidation technology and organic wastewater controlling approaches inside and outside country, organic wastewater treated by photocatalytic oxidation 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. The main contents of experiment were as follows:Dark reaction and blank experiment made out, simple photocatalyst or simple illumination can neither proceed photocatalytic oxidation reaction. Photocatalytic oxidation reaction can occur in the existence both of photocatalyst and of UV irradiation.Using acid red 3B as objective pollutant in screening photocatalyst test, photocatalytic activity of tantalate, niobate and a series of perovskite-like catalyst was analyzed and reviewed respectively. The results indicated that the photocatalyticactivity of KCa2Nb3010 and KSr2Nb3010 loaded with NiO was good comparatively, when compared to their photodegradation effect foracid red 3B.Acid red 3B was selected as representative organic pollutant to simulate organic wastewater, which was treated by photocatalytic oxidation using KCa2Nb3010 as photocatalyst. Factors affecting photocatalytic oxidation reation were studied in details, such as catalyst amount, loaded content, time of UV irradiation, initialconcentration of wastewater, pH value, etc. the approaches to improve photocatalyst activity of KCa2Nb3010 were also investigated from the temperature and time of calcining, pillaring of TiO2 and other aspects.Acid red 3B was again selected as representative organic pollutant to simulate organic wastewater which was treated by photocatalytic oxidation using KSr2Nb3O10 as photocatslyst, the influence of the above-described factors affecting photodegradation effect were further studied. On the basis of mono-factor test, effects of photocatalysts were reviewed stressly. Namely, the difference of photocatalytic performances of KCa2Nb3O10 and KSr2Nb3O10 was discussed from the temperature of calcining, initial concentration of solution, loading of NiO and so on. Experiment indicated, whether they were loaded with NiO or not, the photocatalytic performances of KSr2Nb3O10 were better than KCa2Nb3O10 generally. And catalysts prepared were characterized to analyze their difference by X-ray diffraction (XRD) and scanning electric microscope (SEM).In addition, the mechanism of photocatalytic oxidation technology degrading organic pollutants was comparatively discussed in details, and the degrading mechanism of acid red 3B was tried to probe into.