Phosphorus retention and release by sediments in the eutrophic Mai Po Marshes, Hong Kong
Phosphorus retention and release by sediments in the eutrophic Mai Po Marshes, Hong Kong
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DOI：
10.1016/j.marpolbul.2008.01.038
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发表时间：
2008-01-01
影响因子：
5.8
通讯作者：
Lam, Kin Che
中科院分区：
文献类型：
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作者：
Lai, Derrick Yuk Fo;Lam, Kin Che
本研究探讨了香港米埔沼泽富营养化区沉积物对磷的截留和释放特性。化学分馏结果表明，沉积物中无机磷的总量超过50%，以氧化还原敏感的铁结合态磷（Fe（OOH）近似于P）为主。由于米埔沉积物中Fe（OOH）P的平均浓度高达912微克/克（-1），因此在低氧化还原电位下，米埔沉积物显示出释放生物有效磷的巨大潜力。米埔沉积物柱芯所录得的平均厌氧磷通量高达31.8 mg m（-2）d（-1），进一步证实了这一点，显示底部沉积物是磷的净来源。虽然米埔沉积物的Langmuir吸附最大值为16423582 mg kg（-1），但其零平衡磷浓度（0.02-0.51 mg L-1）较高，表明即使外来磷负荷进一步减少，沉积物的吸附过程仍有助于维持上覆水体的富营养化状况。我们应共同努力，减少P的内部负荷，特别是在还原条件下，以配合后海湾零排放政策的实施，从而有效地减少米埔沼泽区的富营养化和长远的水质改善。(c)2008爱思唯尔有限公司保留所有权利。
This study examined the phosphorus retention and release characteristics of sediments in the eutrophic Mai Po Marshes in Hong Kong. Results of chemical fractionation show that the sum of inorganic P pools exceeded 50% of the total sediment P content, with the redox-sensitive iron-bound P (Fe(OOH)approximate to P) being the dominant P fraction. Given the considerable average Fe(OOH) P concentration of 912 mu g g(-1), Mai Po sediments demonstrated a great potential to release bioavailable P under low sediment redox potentials. This was further supported by the high mean anaerobic P flux of 31.8 mg m(-2) d(-1) recorded in Mai Po sediment cores, indicating the role of bottom sediments as a net P source. Although sediments in Mai Po had appreciable Langmuir adsorption maxima (16423582 mg kg(-1)), the high zero equilibrium P concentrations (0.02-0.51 mg L-1) obtained suggest that sediment sorption processes would contribute to sustaining the eutrophic conditions in overlying water column even with a further reduction in external P load. Concerted efforts should be made to reduce internal loading of P, especially under reducing conditions, to complement the implementation of zero discharge policy for Deep Bay for effective eutrophication abatement and long-term water quality improvement in the Mai Po Marshes. (c) 2008 Elsevier Ltd. All rights reserved.