珊瑚岛礁淡水透镜体的生物修复研究

Bioremediation research of freshwater lens in a coral island

运用半模理论，研制了高1．2m、直径1.5m的半圆柱体实验平台，对受到有机污染的珊瑚岛礁淡水透镜体进行原位曝气生物修复研究。研究了溶解氧（Dissolved Oxygen，DO）在地下水中的分布规律及脱色和化学耗氧量（Chemical oxygcn demand，COD）的去除效果。结果表明：（1）径向上，在主流区半径R为0．2～0．5m的范围内，DO的质量浓度随R的增大而增大。R〉0．5m，DO的质量浓度随R的增大而降低。垂向上，DO的质量浓度随高度的增大而迅速增大。（2）地下水色度和COD均随曝气时间的增加而降低，色度为40度、COD为96mg／L的原水，曝气18d后，色度均不超过15度，曝气30d后，色度不超过10度，COD为21～36mg／L。以色度不超过15度作为修复的标准，修复区半径R达0．7m，修复区高度H为0．9m。（3）修复1m^3的上述原水和1．3m^3土壤所需的空气量约为211m^3。

Semi-cylinder experiment platform of 1.2 m high and 1.5 m diameter was developed by applying semi-module theory and bio-restore of freshwater lens contaminated by organic pollutant was conducted in-situ in a coral island. DO（Dissolved Oxygen） distribution character in underground water and de-colorization, COD（Chemical oxygen demand） removal effect were studied. The results showed： （1） On the radial direction, DO increased with radius R between 0.2 m and 0.5 m of R in the main current area, but reduced with R increasing in the R〉0.5 m area. On the vertical direction, DO increased rapidly with height H. （2） Both color and COD of the water reduced with aeration time increasing, the color didn＇t exceed 15 after 18-day aeration, and the color didn＇t exceed 10 and COD was between 21-36 mg/L after 30 day aeration for the raw water with color 40 and COD 96 mg/L. Taking color≤15 as a bioremediation standard, the radius and the height of bioremediation area were 0.7 m and 0.9 m respectively. （3） The gas volume needed was about 211 m^3 to bio restore the raw water of lm^3 and soil polluted of 1.3 m^3.