改性TiO_2/浮石光催化去除二级出水中有机物

为了实现城市污水厂二级出水的回用,将La3＋、Fe3＋共掺杂TiO2/浮石光催化用于二级出水中有机物的去除。在优化工艺条件下,该方法对TOC的去除率为49.0%,对UV254的去除率为76.5%;出水BDOC/DOC值大幅度提高,由最初的0.21提高到0.56,增加了出水的可生化性;二级出水中存在着影响光催化去除有机物的因素,其中阴离子对有机物的去除有一定的抑制作用;光催化反应在通过O3强化后对有机物的去除率得到提高,TOC的去除率达到75.0%,光催化和O3氧化对有机物的去除具有协同效应;随着光催化反应次数的增加,催化剂活性有下降趋势,使用10次后TOC去除率下降到第一次使用时的16.7%,再生能够使催化活性恢复到使用前的95%,催化剂在使用15次以内稳定性较好。

Removal of organic pollutants in secondary effluents by modified TiO2 pumice photocatalyst

In order to reuse the secondary effluents, the removal of organic pollutants in secondary effluents by modified TiO2 pumice photocatalyst was investigated. Under the optimum conditions, the reduction rate of TOC was 49.0% ,and the UV2s4 was 76.5% in pbotocatalytic process. In this process, the BDOC/DOC in- creased from 0.21 to 0.56 and the macromolecular organics of water were broken down into low molecules which improved the effluents＇ bio-degradability. Negative ion in ~ater inhibited the organic pollutant＇ removal rate. The process of TiO2/UV/O3 was much more efficient than TiOz/UV in removing TOC, which the removed rate reached to 75.0%. The both processes possessed synergetic action on organics＇ removal. The photocatalytie ac- tivity decreased with the increasing of repeated use. After been used for ten times, the reduction rate decreased to 16.7 %. The activity of used photocatalyst could resume 95 % by certain regeneration method. The TiOz catalyst kept effective during the continual use of 15 times.