| 城市重污染河道底泥对外源磷的吸附和固定机制 |
| 摘要点击 2743 全文点击 2004 投稿时间：2010-01-09 修订日期：2010-03-25 |
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| 中文关键词 底泥 吸附 磷形态 磷平衡浓度 |
| 英文关键词 sediment adsorption phosphorus fraction zero equilibrium phosphorus concentration |
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| 中文摘要 |
| 以重污染河道底泥和上覆水为材料，研究了周期性加入外源磷条件下，间歇扰动对底泥吸附和固定外源磷的作用机制.结果表明，扰动状态下，39d内底泥对外源磷的累积吸附量达到363.4 mg·kg-1，远高于静态试验(213.2 mg·kg-1).内源磷形态分析表明，扰动状态下底泥吸附的外源磷中超过61%被结合到铁铝结合态磷(Fe/Al-P)中，而静态试验则上升为83%.考虑到Fe/Al-P的生物有效性，结合到非闭蓄态铁铝结合态磷中的外源磷分别占40.6%(扰动试验)和59.5%(静态试验).另外，扰动状态下，超过23%的底泥吸附的外源磷结合到钙结合态磷(HCl-P)，而静态试验中HCl-P基本保持不变.底泥吸附外源磷后，2种底泥磷最大吸附容量(Smax)均有所降低，而扰动后底泥的磷平衡浓度(EPC0)、磷饱和度p(%)的增加幅度明显低于静态试验底泥.因此推测，底泥扰动不仅可以加快底泥对磷的吸附，而且提高了内源磷持留能力. |
| 英文摘要 |
| The mechanisms of phosphorus (P) adsorption and immobility were investigated in laboratory experiments. The sediments and waters used were taken from an inner-city heavily polluted canal. Addition of KH2PO4 into the operated experimental units，with and without (i.e.，static) intermittent sediment resuspension，were made similar to the external P input and carried out periodically. The results show that the amount of the accumulative P adsorption onto the sediments was up to 363.4 mg·kg-1 under the conditions of sediment disturbance over a 39-day period，and it was evidently higher than that (213.2 mg·kg-1) under static conditions. Sequential fractionation indicated that most of the incorporated P was accounted for in the Fe/Al-P. There were over 61% in the case of intermittent sediment disturbance and up to 83% in the case of static conditions. Based on the bioavailability of Fe/Al-P，40.6% of the incorporated P was accounted for in non-occluded Fe/Al-P of the sediments under intermittent sediment disturbance conditions. This value increased to 59.5% under static conditions. In addition，more than 23% of the incorporated P was accounted for in HCl-P of the sediments under intermittent sediment disturbance conditions，on the other hand，the concentration of HCl-P kept relatively constant under static conditions. After 39 d of P adsorption by the both sediments，the values of the maximum sorption capacity (Smax) decreased，while zero equilibrium P concentration (EPC0) and P saturation p(%) increased. However，the extent of EPC0 and P% under intermittent sediment disturbance conditions was obviously lower than that under static conditions. It was hopefully suggested that intermittent sediment disturbance can not only accelerate the P adsorption but also enhance the P retention by sediments. |
