摘要
5种水生植物对所用4种放射性同位素都有一定的清除能力,其清除能力的大小不仅取决于生物的种类,而且还取决于生物本身代谢率的高低。试验结果:去污率高的可达80%,积累系数最高可达1,500;水体中含Ca量的多少对生物吸收积累放射性物质的多少有一定的影响;生物在积累放射性物质之后,转移到无放射性物质的水体中将释放出原积累的一部分放射性物质。
Spirogyra sp., Hydrodictyon reticulatum (L.) Lager, Spirodela polyrhiza (L.)Schleid., Ceratophyllum demersum L., and Eichhornia crassipes Sohms, all have certainability of absorbing and accumulating Sr^(90), Y^(91), Cs^(137) and Ce^(144). The coefficient of accumulation and percentage of clearance are negatively relatedwith the concentration of the stable calcium in the water, but positively with theduration of the experiment. The same species of aquatic plant have different coefficients of accumulation fordifferent kinds of radioactive materials. For instance, on the eighth days, the coefficientof accumulation by Ceratophyllum demersum was: Ce^(144)-1500. Sr^(90)-1220, Y^(91)-480,Cs^(137)-160. Different species of aquatic plants have different abiiity to absorb andaccumulate the same kind of radioactive material. Thus, the coefficient of accumula-tion of Sr^(90) on the eighth days was: Spirodcta polyrhiza-1380, Ceratophyllum demer-sum-1220, Spirogyra sp. -820, Hydrodictyon reticulatum-460, Eichhornia crassi-pes-380. Inasmuch its aquatic plants can accumulate radioactive materials, the use ofaquatic plants to purify the water polluted by Sr^(90), Y^(91), Cs^(137), Ce^(144), etc. has itssignificance not only in theory but also in practice.
