摘要
文献中,放射性污染物在地下水中有吸附迁移方程的衰变项,表示为:-λC Rd。该形式是在将吸附相质量与溶解相质量加和后一并考虑;或者是将吸附相与溶解相的质量变化都包含在质量守恒方程中导出的。这种观点及方法,忽视了在局部平衡假设成立条件下,吸附分配系数(Kd)和滞留系数(Rd)为定值的事实,误将吸附相也作为迁移组分;还忽略了使用质量守恒定律时,必须以溶质具备示踪剂性质为前提条件。所以,表达式中的"-λC Rd"有误。实际上,在平衡状态下,吸附相不迁移,吸附作用使地下水净化。吸附相的衰变作用与迁移方程的衰变项无关。衰变项是指地下水中污染溶质的衰变作用,其数学表达式应为:C/t=-λC,而不是-λC Rd。后者会造成虚假的衰变影响,从而导致环境安全评价存在重大失误隐患。
In the literature, the decay term of adsorptive radioactive wastes is expressed as ＂-λCRd＂ in the groundwater transport equation. This expression accounts for the sum of the adsorption mass and the dissolved phase mass, or includes the mass change of the adsorption and the dissolved phase in the mass conservation equation. This viewpoint and the measure overlook the fact that under the assumption of the local equilibrium, the partition coefficient of adsorption （Kd） and the retarded coefficient （Rd） are fixed values, mistake the adsorption phase for transport constituents, and lose sight of that when the mass conservation equation is used the precondition is that the solute must have the characters of the trace reagent. Therefore, the expression of -λCRd is wrong. In fact, in the equilibrium state, the adsorption phase does not transport, and adsorption effect will clean the groundwater. The decay effect of the adsorption phase is independent of the decay term in the transport equation. The decay term is the decay effect of the contaminative solute, thus the math expression should be δC /δd =-λC in stead of --λCRd. The latter has a false decay influence that will lead to magnitude hidden trouble in the safety evaluation of the environment.
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2010年第1期110-112,共3页
Journal of Chengdu University of Technology: Science & Technology Edition
