稀土催化臭氧氧化法降解印染废水的研究

Degradation of Dyeing Wastewater by Rare Earth Catalytic Ozone Oxidation

以硅酸钠为原料,含稀土的盐酸为溶剂,采用化学沉淀法制备了二氧化硅负载型稀土催化剂。实验结果表明,最佳制备工艺条件为硅酸钠浓度0.3 mol/L、盐酸浓度1.0 mol/L、表面活性剂选用十二烷基苯磺酸钠、稀土投加量0.1 g、温度在800℃以上、煅烧时间1 h。利用IR、UV-VIS、XRD、SEM等表征手段研究了二氧化硅负载型稀土催化剂的组成、形貌。在此最佳条件下所制得的催化剂平均粒径为17 nm,比表面积为1 365 m2/g。制备的催化剂具有良好的催化活性,且附着的稀土离子不易流失,解决了稀土流失问题,并易与反应体系分离,可回收和重复利用。并利用该催化剂催化臭氧对模拟废水和实际废水进行处理,在pH为2,稀土催化剂的投加量为5 g,反应时间为60 min,温度为60℃的最佳反应条件下的COD降解率分别是90.3%和82.2%。

With the way of chemical sediment,Na2SiO3 as primary material,hydrochloric acid including rare earth as solvent,SiO2 used as carrier to absorb the rare earth catalyst is obtained.Experimental results show that the optimal preparation conditions is sodium concentration 0.3 mol/L,concentration of hydrochloric acid 1.0 mol/L,sodium dodecyl benzene sulfonate used as surfactant,rare earth dosage 0.1 g,temperature above 800 ℃,calcining time 1 h.The composition and morphology of the catalyst have been described by IR、UV-VIS、XRD and SEM.In the optimal conditions the catalyst is obtained and the average particle size is 17 nm,specific surface area is 1 365 m2/g.The catalyst with highest activity and the adherent rare earth ion is difficult to lose.It also got easy to separate from reacting system,recycle and reuse,the erosion of rare earth is resolved.The simulated wastewater and dyeing wastewater was degraded by rare earth catalytic ozone oxidation with best reaction conditions as pH value 2,carrying rare earth catalyst amount 5 g,reaction time 60 min,temperature 60 ℃,the removal rates of COD reached 90.3% and 82.2%.