因為滲透性反應牆與含水層兩者不同的物理與化學性質使得污染物通過滲透性反應牆-含水層系統的傳輸行為變得非常複雜，雙區污染物傳輸模式為了解污染物通過滲透性反應牆-含水層系統化學反應傳輸各種過程與機制的有效工具。對降解性的污染物的傳輸而言，多物種傳輸模式因為能同時考慮母物種與子物種不同的傳輸與反應化學性質，因此能納入考慮來自於母物種的質量累積貢獻。在數學簡單化的考慮下，目前的雙區多物種傳輸解析解模式都是假設平衡吸附推導而得。然而，實驗與理論的研究結果指出非平衡吸附可能對地下環境污染物的傳輸有重大的影響，當採用瞬間平衡吸附假設會造成無法探討非平衡吸附過程的影響。 因此本計畫的目的為發展一全新的雙區多物種傳輸解析解模式來探討在滲透性反應牆-含水層系統降解性污染物的傳輸行為，研究中將納入一階可逆動力吸附反應方程式於分別描述滲透性反應牆與含水層的兩組一階降解反應方程式耦合的移流-延散方程組以探討滲透性反應牆-含水層系統的非平衡傳輸行為，利用Laplace積分轉換法結合通用型積分轉換法可求解得此複雜控制方程系統的解析解，所發展解析解與其對應的計算程式的正確性將藉由比較解析解與平衡吸附的雙區解析解和Laplace轉換有限差分法求解相同控制方程系統的數值解加以確認，所推導得的解析解將用來探討吸附反應速率對滲透性反應牆-含水層系統功能表現的影響。 ;Transport behaviors of contaminants through a permeable reactive barrier (PRB)-aquifer system are complicated because of the different physical and chemical properties of the PRB and the aquifer. Dual-domain contaminant transport models are efficient tools for better understanding the various processes and mechanisms of reactive transport through a PRB–aquifer system. Multispecies transport models should have the ability to account for mass accumulation from parent species while simultaneously considering the distinct transport and reactive properties of both the parent and daughter species during the transport of degradable contaminants. For mathematical simplicity, the current multispecies dual-domain transport analytical models are derived assuming equilibrium-controlled sorption. However experimental and theoretical research results indicate that nonequlibrium sorption could have a profound effect upon solute transport in the subsurface environment. The making of the instantaneous equilibrium sorption assumption precludes consideration or examination of the potentially significant impact of the nonequilibriun sorption process. This study is thus designed to develop a novel dual-domain multispecies transport analytical model for the reactive transport of degradable contaminants through a PRB–aquifer system. The first-order reversible kinetic sorption reaction equation system is incorporated into two sets of simultaneous advection-dispersion equations coupled by sequential first-order decay reactions that describe the multispecies nonequlibrium transport in both the PRB and the aquifer. The analytical solutions to the complicated governing equation system can be obtained by using the Laplace transform and the generalized integral transform technique. The correctness of the derived analytical model and its corresponding computer code will be evaluated by comparison of the computational results against those obtained with the equilibrium-controlled sorption analytical model and a numerical model where the same governing equations are solved using the advanced Laplace transform finite difference method. Ultimately, the derived analytical model will be used to investigate how the sorption reaction rate influences the performance of a PRB-aquifer system.
