紫色母岩覆盖层控制底泥磷释放的效果及机制

Efficiency and Mechanism of Capping with Purple Parent Rocks to Control Phosphorus Release from Sediments

选取重庆地区分布面积较广的3种紫色母岩(飞仙关组、蓬莱镇组和遂宁组),和2种经众多研究证明可有效控制底泥污染物释放的岩石(石灰石和方解石)作为活性覆盖材料,进行底泥覆盖模拟实验,研究紫色母岩覆盖层对底泥磷素释放的控制效果及机制.结果表明,3种紫色母岩覆盖层对底泥总磷向上覆水体释放的抑制作用较强,远好于方解石与石灰石(P<0.05).其中,飞仙关组紫色母岩覆盖层对底泥总磷向上覆水体释放的抑制效果最好,抑制率为94.4%.5种覆盖材料均可促进底泥总磷的释放与转化,显著促进底泥OP原位转化为Ca-P,而3种紫色母岩覆盖层更有利于底泥释放出的磷转化为无机磷和有机磷.同时,5种覆盖材料均会改变底泥及上覆水体微生物的群落结构,其中PLFA16:0标记的细菌数量与上覆水体的总磷含量呈显著负相关.

In order to study the efficiency and mechanism of capping with purple parent rocks to control phosphorus release from sediments,three kinds of purple parent rocks（ Fei-xian-guan Formation,Peng-lai-zhen Formation and Sui-ning Formation） which distribute widely in Chongqing,and two types of rock（ limestone and calcite） which have been found to effectively control the release of phosphorus from sediments,were selected as active covering materials to cap the sediments to conduct simulation experiment. The results indicated that： all three kinds of purple parent rocks showed strong inhibition of total phosphorus release from sediments to the overlying water,far better than limestone and calcite（ P 〈0. 05）,and the highest removal rate of total phosphorus was 94. 4% in the disposal of Fei-xian-guan Formation. Those five kinds of covering materials could promote the release and transformation of total phosphorus in sediments,which could significantly promote the in situ conversion of OP to Ca-P,while the three kinds of purple parent rocks were more conducive to convert the released phosphorus into inorganic phosphorus and organic phosphorus. At the same time,those five kinds of covering materials could also change the microbial community structure in sediments and overlying water,and the numbers of bacteria（ labeled as PLFA16： 0） were significantly negatively correlated with the content of total phosphorus in the overlying water.