H3PMo12O40/活性白土UV - H2O2催化氧化降解甲基橙

采用浸渍吸附法制备了H3PMo12O40/活性白土催化剂,并考察了H3 PMo12O40/活性白土对偶氮染料甲基橙的UV-H2O2降解的催化性能.实验结果表明,当H2O2加入量为0.4 mol/L、H3PMo12O40/活性白土加入量为0.30 g/L、溶液初始pH为2、反应温度为70℃、反应时间为1.0h时,甲基橙去...     

机械力化学活化HPW-TiO_2/膨润土光催化降解甲基橙

采用溶胶-凝胶法制备了磷钨酸(HPW)改性TiO_2,并固载于膨润土上,再经机械力化学活化,得到机械力化学活化HPW-TiO_2/膨润土(MCA-HPW-TiO_2/膨润土)复合光催化剂。采用XRD,SEM,EDS技术对复合光催化剂进行了表征,并将其用于甲基橙的紫外光催化降解。表征结果显示:活性组分TiO_2和HPW成功固载于膨润土上;在机械力化学活化作用下,膨润土层间结构遭到破坏,TiO_2的XRD特征峰形呈弥散状态。实验结果表明:机械力化学活化作用对HPW-TiO_2/膨润土的光催化性能提升效果显著;在酸性及近中性条件下MCA-HPWTiO_2/膨润土均具有较高的催化活性;在溶液p H 6.2、初始甲基橙质量浓度10 mg/L、反应时间180 min、MCAHPW-TiO_2/膨润土投加量1 g/L的条件下,甲基橙去除率达88.27%;该光催化降解过程符合一级动力学模型。     

Preparation of a new Fenton-like catalyst from red mud using molasses wastewater as partial acidifying agent

Using molasses wastewater as partial acidifying agent, a new Fenton-like catalyst (ACRM _sm ) was prepared through a simple process of acidification and calcination using red mud as main material. With molasses wastewater, both the free alkali and the chemically bonded alkali in red mud were effectively removed under the action of H₂SO₄ and molasses wastewater, and the prepared ACRM _sm was a near-neutral catalyst. The ACRM _sm preparation conditions were as follows: for 3 g of red mud, 9 mL of 0.7 mol/L H₂SO₄ plus 2 g of molasses wastewater as the acidifying agent, calcination temperature 573 K, and calcination time 1 h. Iron phase of ACRM _sm was mainly α-Fe₂O₃ and trace amount of carbon existed in ACRM _sm . The addition of molasses wastewater not only effectively reduced the consumption of H₂SO₄ in acidification of red mud but also resulted in the generation of carbon and significantly improved the distribution of macropore in prepared ACRM _sm . It was found that near-neutral pH of catalyst, generated carbon, and wide distribution of macropore were the main reasons for the high catalytic activity of ACRM _sm . The generated carbon and wide distribution of macropore were entirely due to the molasses wastewater added. In degradation of orange II, ACRM _sm retained most of its catalytic stability and activity after five recycling times, indicating ACRM _sm had an excellent long-term stability in the Fenton-like process. Furthermore, the performance test of settling showed ACRM _sm had an excellent settleability. ACRM_sm was a safe and green catalytic material used in Fenton-like oxidation for wastewater treatment.