中文关键词
原位覆盖底泥微环境内源磷固定 英文关键词in situ cappingsedimentmicroenvironmentsedimentary phosphorusfixation |
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中文摘要 |
底泥微环境对内源磷释放有重要的影响.本研究对比了2种不同的原位覆盖材料对底泥微环境的影响以及内源磷释放的控制效果,沉积物微环境以间隙水中NH4+-N、Fe2+浓度和微生物活性来表示.结果表明,CaO2改性材料(ACPM)覆盖条件下较锁磷剂(Phoslock®)组NH4+-N和Fe2+浓度均处于较低状态,微生物活性值FDA增加了42.57%,说明其微生物活性较高,也显示了ACPM覆盖下其氧化还原电位高于Phoslock®,且底泥微环境处于好氧状态.与Phoslock®组相比,ACPM组上覆水和间隙水中DIP浓度均较高,表明Phoslock®对磷酸盐的吸附能力优于ACPM,也暗示了底泥微环境并不是磷吸附的唯一衡量标准.在内源磷固定过程中,2种覆盖材料均有利于内源磷的固定,Ca-P均显著增加.然而,具有氧化性的ACPM导致NH4Cl-P增加,Fe/Al-P大量减少,促进了活性磷的释放,使得底泥中的磷向覆盖层迁移,有利于清洁底泥. |
英文摘要 |
The sediment microenvironment has an important effect on the release of endogenous phosphorus. In this study, the influence of two different in-situ covering materials on the sediment microenvironment were compared, and the controlling effect of endogenous phosphorus release were studied. The sediment microenvironment was represented by the concentration of NH4+-N, Fe2+ in interstitial water, and microbial activity. The results showed that the concentrations of NH4+-N and Fe2+ were lower under ACPM coverage than those of the Phoslock® group, and the microbial activity was higher, indicating that the redox potential of ACPM coverage was higher than that of Phoslock®. Furthermore, the bottom sediment microenvironment was in an aerobic state. Compared with the Phoslock® group, the DIP concentrations in both the overcover water and porewater in the ACPM group were higher, indicating that Phoslock® was superior to ACPM with respect to the phosphate adsorption capacity, suggesting that the sediment microenvironment was not the only criterion for phosphorus adsorption. In the fixation process of endogenous phosphorus, both of the covering materials were conducive to the fixation of inter phosphorus, and Ca-P increased significantly. On the other hand, oxidizing ACPM led to an increase in NH4Cl-P and a significant decrease in Fe/Al-P. This promotes the release of active phosphorus, which is conducive to the cleaning of the sediment and phosphorus release. |
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