改性沸石的沉积物磷钝化效果研究

通过室内模拟实验,对天然沸石及不同方法改性沸石的磷吸附性能及沉积物磷钝化效果进行了对比研究。磷吸附实验结果表明,磷吸附量大小为改性沸石Z3>改性沸石Z2>改性沸石Z1>天然沸石,35d的平均吸附量分别为832、466、168和70mg/kg。改性沸石的磷吸附量与沸石含量正相关,并随时间呈增长趋势,其中改性沸石Z3第35d的磷吸附量可达1690mg/kg。离子交换量测定结果显示,沸石经改性后促进了Ca2+的释放,同时减少了K+、Na+的释放量。沉积物磷钝化实验表明,改性沸石可有效减少沉积物TP、DRP的释放,减少释放量达80%以上。天然沸石主要通过表面吸附减少水体磷含量,其次,物理阻隔作用拓展了钝化作用的时间和空间。Al(OH)3絮凝物通过表面吸附、电中和及架桥作用可显著提高改性沸石的磷吸附量,增强沉积物磷钝化效果。

The Sediment P inactivation Efficiency of Modified Zeolite

The capacity and efficiency of natural and modified zeolite used for controlling P release from lake sediments has been investigated.The results show that the capacity of P absorption is in the order of zeolite Z3 > modified zeolite Z2 > modified zeolite Z1 > natural zeolite,with a mean absorption of 832,466,168and 70 mg/kg,which is positively correlated with the content of zeolite.The capacity of P absorption of modified zeolite Z3 is as high as 1690 mg/kg to the 35th day.Modified zeolite could reduce P release from sediments with the zeolite and alum cooperation efficiently.Zeolite could prevent P releasing from sediments and absorb P from overlying water.Al(OH)3 floc promotes the P inactivation efficiency by absorption,charge neutralization and bridging action.It could also promote Ca2+ and inhabit Na+ to release from natural zeolite.