藻类强化光降解去除水中双酚A的动力学研究

Kinetics of photo-degradation of bisphenol enhanced by algae in aquatic environment

为提高污染水体中双酚A光降解效率,采用铜绿微囊藻进行强化,研究该藻强化光降解去除水中双酚A的效能和动力学规律,并讨论了藻质量浓度、pH值及光源等因素对降解速率的影响.研究表明,藻类质量浓度相对较大时,光降解反应符合假一级反应动力学规律,提高反应液中藻类质量浓度可提高双酚A的降解率;pH值对光降解速率有显著影响,当pH值为5时,反应速率达到最大值;光源对反应速率也存在影响,光源采用紫外灯时,光降解反应速率是同条件下高压汞灯作为光源时的9倍,其原因是后者不能使反应液中产生大量的羟基自由基.

Microcystis aeruginosa was used in this study to enhance the photo - degradation of bisphenol A （BPA） in the polluted water body. Firstly, the efficiency and kinetics of BPA photo - degradation enhanced by microcystis aeruginosa were investigated. Effects of some factors, such as algae dosage, pH value and light source, on the rate constant of the photo - degradation reaction, were studied as well. The results showed that the photo -degradation reaction of BPA in algae solution follows the law of pseudo - first order reaction kinetics when algae was excessive, the photo - degradation rate of BPA was increased with the algae con- centration increasing. The photo -degradation rate constant was influenced by the pH value of the solution, and it reached the highest level when pH = 5. The rate of photo - degrada- tion reaction was 9 times greater by using a UV lamp as light sources than using a HPML lamp, due to less production of hydroxyl radicals by HPML lamp illumination.