Xiong Qiang, Jiao Li Xing, Wang Sheng-Rui, Peng Xi-Long
Huan Jing Ke Xue. 2014 Nov;35(11):4118-26.
The content and vertical distribution characteristics of organic phosphorus were studied by collecting core sediments of Dianchi Lake, characterizing the bioavailability of different organic phosphorus species of these sediments by enzymatic hydrolysis. The results indicated that, (1) The inorganic phosphorus represented primary portions of extractable phosphorus of sediments in Dianchi Lake, except for the H2O extractable organic phosphorus (H2O-P(o)). The rank of order of organic phosphorus fractionation in sediments was NaOH extractable organic phosphorus (NaOH-P(o)) > NaHCO3 extractable organic phosphorus (NaHCO3-P(o)) > H2O-P(o) > HCl extractable organic phosphorus (HCl-P(o)). The vertical distribution of NaOH-P(o), NaHCO3-P(o) and H2O-P(o) with relatively high mobility showed the trend of topper layer > middle layer > bottom layer. (2) Labile monoester P predominated in enzymatically hydrolysable phosphorus (EHP) of sediments in Dianchi Lake. The EHP content of NaOH-P0, NaHCO3-Po and H20-P0 in sediments of Dianchi Lake were 0.11-5.93, 0-45.32 and 0-107.11 mg x kg(-1), respectively. The EHP content of different organic phosphorus species followed the order: NaOH-P(o) > NaHCO3-P(o) > H2O-P(o), with the trend of vertical distribution of topper layer > middle layer > bottom layer. The bioavailability of organic phosphorus of different depth showed the order of topper layer > middle layer > bottom layer. (3) EHP was a considerable source of the bioavailable phosphorus of sediments in Dianchi Lake. The protection of water quality in Dianchi Lake should consider the effects of EHP in sediments. When the external phosphorus load was restricted gradually, the biogeochemical cycle of EHP in sediments might play an important role in maintaining the eutrophication of Dianchi Lake.
通过采集滇池柱状沉积物，采用酶解方法表征沉积物中不同有机磷形态的生物有效性，研究了有机磷的含量及垂向分布特征。结果表明：（1）滇池沉积物中可提取磷以无机磷为主，除水提取有机磷（H2O-P(o)）外。沉积物中有机磷分级顺序为氢氧化钠提取有机磷（NaOH-P(o)）＞碳酸氢钠提取有机磷（NaHCO3-P(o)）＞H2O-P(o)＞盐酸提取有机磷（HCl-P(o)）。迁移性相对较高的NaOH-P(o)、NaHCO3-P(o)和H2O-P(o)垂向分布呈现表层＞中层＞底层的趋势。（2）滇池沉积物酶解磷（EHP）中不稳定单酯磷占主导。滇池沉积物中NaOH-P0、NaHCO3-Po和H20-P0的EHP含量分别为0.11 - 5.93、0 - 45.32和0 - 107.11 mg·kg(-1)。不同有机磷形态的EHP含量顺序为：NaOH-P(o)＞NaHCO3-P(o)＞H2O-P(o)，垂向分布趋势为表层＞中层＞底层。不同深度有机磷的生物有效性顺序为表层＞中层＞底层。（3）EHP是滇池沉积物生物有效磷的重要来源。滇池水质保护应考虑沉积物中EHP的影响。当外部磷负荷逐渐受到限制时，沉积物中EHP的生物地球化学循环可能在维持滇池富营养化方面发挥重要作用。
