纳米氢氧化钛及焙烧产物对磷酸根的吸附特性研究

Study on the Adsorption Characteristic of Phosphate by Nano-Titanium Hydroxide and Calcined Product

以纳米氢氧化钛(NTH)作为吸附水溶液中磷酸根的吸附剂,考察了NTH不同焙烧温度下的分子式及其对PO4吸附效果的影响。选择PO4初始浓度为50mg/L,通过正交试验确定在pH=2、吸附剂用量为0.1g、吸附时间3-3-为40min、温度25℃时,NTH吸附效果达到最佳,吸附量为55.5mg/g,经200、300、400及500℃焙烧后的NTH对磷酸根的吸附量逐渐减小;吸附量分别为49.4、40.6、25.5及16.8mg/g;NTH经800℃焙烧后,焙烧产物TiO2不具有吸附性。TG、XRD分析表明随着焙烧温度的升高,NTH的表面活性基团(-OH)数量逐渐减少。结果表明,吸附剂的吸附性与吸附剂表面羟基的数量有直接关系。

Taking Nano-titanium hydroxide （NTH） as the adsorbent of phosphate,the molecular formulas of NTH at different calcination temperature were studied,and the effect of the calcination temperature on the adsorption of the phosphate was investigated.Selecting the initial concentration of phosphate at 50 mg· L-1,at the orthogonal experiments conditions of pH=2,adsorbent dosage 0.1 g,adsorption time 40min and 25 ℃,the result of adsorption is the best,meanwhile,the adsorption capacity of NTH was 55.5 mg.g-1.The adsorption capacities of the NTH after calcination at 200 ℃,300 ℃,400 ℃,500 ℃ were dramatically decreased,they were 49.4,40.6,25.5 and 16.8 mg· g-1,respectively.Calcination at 800 ℃,the calcined product was TiO2 and the adsorptivity disappeared.TG,XRD analysis showed that the number of surface active groups （-OH） of NTH reduced with the increasing of calcined temperature.According to above research,the adsorptivity is related to the number of the surface hydroxyl directly.