Li^+-TiO_2复合纳米光催化剂制备及其光催化降解海产品深加工废水的研究

Preparation of Li^+-doped nanometer titanium dioxide and its photocatalytic degradation of seafood processing effluents

对Ti O2纳米光催化材料进行掺杂改性,利用溶胶-凝胶法制备出掺杂锂的Li+-Ti O2复合纳米光催化剂,通过X射线衍射分析(XRD)、扫描电镜分析(SEM)等测试技术对所制备的光催化剂形态结构和特性加以表征,用大连市黑石礁海域的海水配制成模拟海产品深加工废水,研究了Li+-Ti O2复合纳米光催化剂光催化降解海产品深加工废水的能力及影响其降解能力的因素,并确定了Li+-Ti O2光催化剂光催化降解海产品深加工废水的优化试验条件。结果表明:Li+-Ti O2复合纳米光催化剂光催化降解海产品深加工废水效率高,锂掺杂量、催化剂用量、p H、氨氮初始浓度、COD初始浓度和过氧化氢(H2O2)用量6个因素影响光催化降解的能力,在优化试验条件下,即锂掺杂量为5%,氨氮初始浓度为80 mg/L,COD初始浓度为300 mg/L,Li+-Ti O2用量为0.9 g/L,H2O2用量为5%,反应时间为2 h,p H值为8时,海产品深加工废水中氨氮和COD的光催化氧化降解率分别达到81.50%和78.67%。

The crystal structure and surface morphology of Li＋-doped nanometer TiO2 photoeatalyst prepared via egradation of seafood process- TiO2 in the simulated seawa- ter. The factors affecting the degradation including doping content of Lithium, Li＋-doped TiO2 dosage, pH value, initial concentration of COD and ammonia-N were studied and the effect of presence of assistance oxidant peroxide on the COD and ammonia-N removal from sea food processing effluents was investigated in an orthogonal test to optimize the photocatalytic degradation of seafood processing effluents. It was found that the Li＋-doped nanometer titanium dioxide photocatalyst was characterized by high photocatalytic degradation of seafood processing effluents, and that the degradation was primarily influenced by purity and dosage of the Li＋-doped nanometer titanium diox- ide, pH value, and initial concentration of COD, addition of H202 and ammonia-N. The best photocatalytic degra- dation of seafood processing effluents was observed under conditions as ： 5 % of lithium doping amount, ammonia ni- trogen concentration of 80mg/L, the initial COD concentration of 300mg/L, Li＋-TiO2 dosage of 0.9 g/L, H2O2 volume fraction of 5%, reaction time of 2 hours, and pH value of 8, with photocatalytic oxidation degradation rate of 81.50% in ammonia nitrogen and of 78.67% in COD.