辽河口芦苇沼泽土壤中汞和甲基汞质量分数变化的模拟研究

Simulation Study on Changes of Mass Fraction of Mercury and Methylmercury in Reed Marsh Soil of Liaohe Estuary

选用辽河口芦苇沼泽0~10 cm和10~20 cm深度的土样,配制不同盐度(0、0.5%、1.0%、1.5%和2.0%)的模拟淹水,分别加入到2种深度的土样中进行培养,在实验的第5、10、15、20、25 d,测定土样中的汞、甲基汞的质量分数.结果表明,随淹水盐度升高,土壤中汞的质量分数有下降趋势.不同深度土壤中甲基汞的质量分数随培养时间的增加,均表现出先降低后升高的趋势;随淹水盐度的升高,土壤中甲基汞质量分数呈下降趋势;土壤中汞的质量分数与土壤pH值、有机质质量分数无明显相关关系,不同盐度下0~10 cm土壤中汞的质量分数与甲基汞的质量分数呈负相关.

The soil samples of 0~10 cm and 10~20 cm depths in the Liaohe estuary reed marsh were selected to prepare simulated flooding with different salinities(0,0.5%,1.0%,1.5%and 2.0%),and added to the soil samples at two depths for cultivation.On the 5 th,10 th,15 th,20 th and 25 th days of the experiment,the mass fractions of mercury and methylmercury in the soil samples were determined.The results showed that as the salinity of flooded water increased,the mass fraction of mercury in the soil had a downward trend.The mass fraction of soil methylmercury of different depths showed a trend of first decreasing and then increasing with the increase of cultivation time;with the increase of flooding salinity,the mass fraction of soil methylmercury showed a downward trend;there is no significant correlation between the mass fraction of mercury in soil and soil pH and organic matter content.The mass fraction of mercury in 0~10 cm soil under different salinities is negatively correlated with the mass fraction of methylmercury.