CAJ | 학술논문

海底沉积物向上覆水体扩散的镭是海洋水体中镭同位素的重要来源之一。为了研究沉积物中镭同位素的解吸和扩散特点,进行了不同盐度和不同粒度条件下224Ra 和226Ra解吸的模拟实验,并通过多个时间段的沉积物培养实验获取224Ra和226Ra的扩散通量。实验结果表明：随着水体盐度增大,沉积物中224Ra、226Ra的解吸量随之增加,在盐度为25时,解吸量基本达到最大值；在同一咸水环境条件下,4个粒级(2000~1000μm、1000~500μm、500~250μm、250~125μm)的沉积物的224Ra、226Ra解吸量比较接近,粒级＞2000μm的224Ra、226Ra解吸量略高于上述4个粒级,而粒级<125μm的224Ra、226Ra解吸量远大于上述5个粒级；胶州湾沉积物中224Ra和226Ra的平均扩散通量分别为0.85 Bq?m-2?d-1和0.022 Bq?m-2?d-1。
해저침적물향상복수체확산적뢰시해양수체중뢰동위소적중요래원지일。위료연구침적물중뢰동위소적해흡화확산특점,진행료불동염도화불동립도조건하224Ra 화226Ra해흡적모의실험,병통과다개시간단적침적물배양실험획취224Ra화226Ra적확산통량。실험결과표명：수착수체염도증대,침적물중224Ra、226Ra적해흡량수지증가,재염도위25시,해흡량기본체도최대치；재동일함수배경조건하,4개립급(2000~1000μm、1000~500μm、500~250μm、250~125μm)적침적물적224Ra、226Ra해흡량비교접근,립급＞2000μm적224Ra、226Ra해흡량략고우상술4개립급,이립급<125μm적224Ra、226Ra해흡량원대우상술5개립급；효주만침적물중224Ra화226Ra적평균확산통량분별위0.85 Bq?m-2?d-1화0.022 Bq?m-2?d-1。
Radium diffusion from sediments to overlying water is one of the important sources of radium isotopes in ocean water. A series of laboratory desorption/diffusion experiments were conducted to help elucidate the characteristics of sediments on224Ra and226Ra desorption and diffusion, which included 1)224Ra and226Ra desorption from sediments in water of different salinities, 2)224Ra and226Ra desorption from sediments of different grain sizes in water of the same salinity, 3)224Ra and226Ra diffusive fluxes by observing Ra enrichment with time in the overlying water of incubated sediments. The experimental results show that there is an increase in the amount of 224Ra and226Ra with the increase of salinity from 5 to 30, and Ra desorption is strongest at the salinity of 25. Under the same salt water condition,224Ra and226Ra desorption activities of the four grain sizes (2000~1000μm, 1000~500μm, 500~250μm and 250~125μm) of sediments are very close to each other. When the grain sizes of sediments are larger than 2000μm, the224Ra and226Ra desorption activities are slightly higher than those of the sediments of the above-mentioned four grain sizes. When the grain sizes of sediments are less than 125μm, the224Ra and226Ra desorption activities are much larger than those of the above-mentioned five grain sizes. The average diffusive fluxes of224Ra and226Ra of sediments from Jiaozhou Bay are 0.85 Bq·m-2·d-1 and 0.022 Bq·m-2·d-1, respectively.