岩溶水系统中微生物迁移机制

The mechanism of microbe transport in karst aquifer systems

对桂林罗锦响水岩岩溶水系统雨前、雨中和雨后水中及悬浮物上携带的细菌数量变化规律分析表明,在雨期,岩溶地下河水质变化对地表水质响应迅速,表现为在一定时期内地下水与地表水中的细菌总数可达到同一个数量级;地下水中TSS与细菌总数的变化具有一致性,即细菌总数随TSS的升降而升降,说明细菌大多是附着在悬浮颗粒物运移的;同时,岩溶区地下河局部存在的溶潭等蓄水构造对污染物具有明显的纳污与稀释效应,是岩溶地下河系统产生自净作用的主要场所。TSS与地下水流速呈正相关,而附着在悬浮颗粒物上的细菌占地下水中细菌总数的比例与流速呈负相关。地下河洞口的堆积物对微生物具有明显的截留作用,其对微生物的吸附和缓慢释放,是导致地下河在很长一段时间内都会受到微生物污染的主要原因。

Bacterial colony counts and TSS in karst water of Luojin Cave,Guilin,were measured before,during and after the rain to determine the transport and attenuation of microbe in karst aquifer systems.It showed that quality of ground water responded quickly to that of surface water,because the bacterial colony counts in ground water and surface water were in the same order of magnitude during the given period.The variation of bacterial colony counts in karst water was in consistence with that of TSS,which illuminates that bacterium transports in kasrt water were achieved by attaching onto SS.Pond in karst conduit could permit and dilute the contamination,and it was the main site to process the natural self-purification in karst water system.Water velocity was positive correlated with TSS,while negative correlated with the ratio of bacteria attached on SS.The deposit at the entrance of the cave can capture and slow release the bacterium,which leads to microbial contamination in karst water for a long period time.