KMnO_4缓释剂的释放性能及其在垃圾渗滤液处理中的应用

Application of controlled release potassium permanganate and its application in treatment of landfill leachate

为延长KMnO4在地下水原位修复中的作用时间,通过改变KMnO4与石蜡的分散方式以及KMnO4与石蜡的质量比(P/W),对KMnO4缓释剂的制备过程进行了优化。采用超声与搅拌联用(搅拌速度150 r/min)的分散方式更有利于KMnO4的均匀分布,随着P/W的升高,KMnO4负载量逐渐增大而绝对回收率逐渐减小。静态实验分别研究了缓释剂在8℃、不同pH与DO浓度下的释放性能。结果表明,在8℃环境下,缓释剂仍具有释放性能;缓释剂受pH影响较大而受DO浓度影响较小。利用缓释剂降解垃圾渗滤液中的COD以及对沉淀物进行定量分析。结果表明,缓释剂对COD去除率可高达57.1%,而沉淀量最少仅为投加纯KMnO4的8.5%。

To extend the duration of KMnO4 in the groundwater in situ remediation,controlled release oxidant was prepared by dispersing the KMnO4 particles in the molten paraffin wax.Preparation conditions,including the decentralized and the weight ratio of KMnO4 to wax（P/W）,were optimized.The results showed that the ultrasonic treatment and the stirring at 150 r/min contributed to the most uniform dispersion of the particles in the molten paraffin wax.KMnO4 loading amount increased with the increasing of P/W,while the absolute recovery rate decreased.The releasing characteristics of the samples in the distilled water were examined by the bench scale tests at 8℃,different pH and dissolved oxygen（DO）.The results showed that controlled release potassium permanganate still had release properties at 8℃.It was significantly affected by pH,whereas was slightly affected by DO concentration.Controlled release KMnO4 oxidant was used to remove COD in the leachate and 57.1% removal efficiency was obtained and the amount of the deposit was only 8.5% of that where virgin KMnO4 was added.