Preparation Of Catalytic Material ?Co₃O₄/ACF? For Peroxymonosulfate And Its Application In Orange ? Degradation

Waste dye-water is a typical organic wastewater which is difficult to be biodegraded.It contains a high concentration of pollutants and toxic substances with deep color.Thus,it is extremely harmful to water and aquatic lives.Therefore,the exploration of scientific and economical treatment of dye-water is of particularly importance.The advanced oxidation technology developed fast in recent years.Theoretically,sulfate radical,SO₄^-·,is better than·OH in oxidizing organic substances,so the advanced oxidation technology based on SO₄^-·has attracted great attention of researchers.In order to develop an efficient and economical catalyst to produce SO₄^-·and to degrade dye-water,18 kinds of activated carbon fibre coated with Co₃O₄?Co₃O₄/ACF?were prepared by solvothermal method and hydrothermal method under three temperatures and three material mixture ratios.The degradation of Orange ? by Co₃O₄/ACF activated peroxymonosulfate?PMS?was studied separately by 18 Co₃O₄/ACF catalysts,and the ones with good catalytic efficiency were selected out as typical Co₃O₄/ACF catalysts.Elemental analysis,SEM,XPS and XRD were used to characterize the typical ones.Then single factor experiments and orthogonal experiments were carried out respectively to study the influence factors and application conditions of the typical Co₃O₄/ACF catalysts.Besides,the recyclability of the Co₃O₄/ACF was investigated and Co²⁺dissolution amount was also determined during the experiment.Moreover,the application of Co₃O₄/ACF in the degradation of real waste dye-water was tested as well.The results were listed as follows:?1?Among9 catalysts prepared by solvothermal method,when the temperature was 140?and the concentration of Co?NO₃?₂ was 0.2 g/L,the product A?0.2-140?showed the best catalytic efficiency.Among the ones prepared by hydrothermal method,when the temperasure was 320?and 0.2 mmol Co?NO₃?₂ dissolved in 40 ml distilled water,the product B?0.2-320?showed the best catalytic efficiency.Catalyst B?0.2-320?,which could completely degrade 100 mg/L orange ? in only 3 min,was even better than A?0.2-140?.The results of material charateration showed that Co₃O₄ was successfully loaded on ACF and the content of Co was around 0.5%.The surface of A?0.2-140?was smooth and Co₃O₄ on it was less than that of B?0.2-320?.B?0.2-320?showed a rough surface and Co₃O₄ particles were coated evenly.?2?Single factor experiments showed that in the setting range of the experiments,Orange ? could be degraded effectively and the degradation rate could accelerate with the increase of PMS or Co₃O₄/ACF.Orthogonal experiments found that the effect of factors on Orange ? degradation from more to less in proper order was degradation time,PMS concentration,Orange ? concentration and amount of catalytic material.?3?In the aspect of recyclability,B?0.2-320?was also better than A?0.2-140?.After recycling for 4 times,the degradation efficiency of orange ? by A?0.2-140?was 47%in60min while that of B?0.2-320?was 99%in 28 min.Co in the composite material B?0.2-320?was 17.2±2.7 mg/g and the dissolved Co²⁺during 4 times recycling to total Co coated was59%.?4?Comparing with Orange ? of similar total organic carbon?TOC?concentration,the real waste dye-water degraded slower by Co₃O₄/ACF catalytic material.However,in neutral pH with 5.7 mmol/L PMS and 0.4 g/L B?0.2-320?,dye-water of 45.7 mg/L TOC concentration could be degraded by 75%in 10 min and by 82%in 25 min.Thus,Co₃O₄/ACF catalytic material is also effective in real dye-water treatment.