14C在水-金鱼藻系统中的消长动态

采用同位素示踪技术研究了14C在水-金鱼藻系统中的消长动态,并运用计算机拟合建立其动力学模型.结果表明,引入水体的14CO32-离子由于金鱼藻的吸附、吸收及转化分解为14CO2气体散逸而使水体中的14C比活度快速下降.金鱼藻因其羽状复叶具有较大的比表面积而对水体中的14C有较强的吸附、吸收作用,其对14C的积累主要在新叶组织中.新叶中14C比活度在第21d出现最大值(29656.59Bq/g),分布百分比达86.34%;水体中14C的消失动态和金鱼藻对14C的积累动态均遵循一级反应动力学模型;金鱼藻各部位对水体中的14C均具有很强的富集作用,可用来监测和净化被14C污染的水体.浓集系数(CF)与时间(t)呈线性关系.

The accumulation and disappearance dynamic of 14C in water-hornwort system

The accumulation and disappearance dynamic of 14C in water-hornwort system was studied adopting isotope-tracer technology and its kinetic models were set up applying computer. The specific activity of 14C in waters reduced quickly because 14CO32- ion drowed into waters decomposed to 14CO2 gas dissipated due to adsorption absorption and transformation of hornwort. Hornwort had stronger adsorb and absorb actions on 14C in waters, because its pinnately compound leaves possessed bigger specific surface area; and its accumulation of 14C was mainly in new leaf organization. The specific activity of 14C in new leaf appeared greatest value of 29656.59Bq/g at 21d, with distribution percent reaching 86.34%. Both the disappearance dynamic of 14C in waters and the accumulation dynamic in hornwort followed the first order reaction kinetics model. Each parts of hornwort all possessed very strong accumulation action on 14C in waters, and could be used for monitoring and purifying the 14C polluted waters. The concentration factor (CF) and time (t) was linear regression relation.