本研究係整合並修改國內外應用廣泛的生化反應方程式,將之放入AQUASIM 2.1水質模擬運算程式中,對人工溼地中的生化反應程序進行動態模擬,而人工溼地水質運算系統,是以混合反應槽(Mixed Reactor,零維)和飽和土體柱(Saturated Soil Column,一維)分別結合生物膜模式(Biofilm Reactor),用此兩組運算模式描述人工溼地動態循環的水理情況,並調整模式中數學運算方程式加入各類生化反應之相關運算式,架構出完整人工溼地水質模擬模式,用以模擬牡蠣殼地下流式人工溼地之出流水質,再對模擬結果做分析,評估生物膜淨化水質之效果。 模式在參數檢驗與模式驗證上採用郭(2009)牡蠣殼礫間處理對水質淨化之研究[14]實測資料作為模式應用之數據,以敏感度分析得出各物質循環中之敏感參數,以提高模式校正效率並了解人工溼地中淨化水質之主要生化反應。研究中以統計方法進行水質項目出流濃度之實測削減量與模擬削減量誤差比較,以驗證模式的適用性。研究結果可得人工溼地敏感參數輸入值範圍,並評估不同設計規格之人工溼地水質淨化功效,作為日後人工溼地系統規劃、設計、操作、管理、診斷之參考與後續模式發展研究之依據。
This study aims at simulating water treatment efficiency of an oyster-shell subsurface flow constructed wetland and assessing the effects of biofilms on water quality improvement by a dynamic simulation model of biochemical processes in wetlands developed by some wildly-applied equations. AQUASIM 2.1 was used as the interface of mathematical calculations to develop the simulation model. Specifically, the Mixed Reactor and Saturated Soil Column were linked with the Biofilm Reactor respectively as two different types of hydrologic systems. The equations of biochemical processes in wetlands were combined into two hydrologic systems respectively to develop water quality simulation models for constructed wetlands. Field sampling data conducted by Guo(2009) were applied in this study for model calibration and validation. To improve the efficiency of model calibration and realize the major factors of water quality in wetlands, sensitivity analysis of parameters in each nutrient cycle was performed before model calibration stage. The error comparison between the simulation and measured outflow concentrations was carried on through statistical analysis to validate the availability of the model. Consequently, the results of the study, including the finding of feasible ranges for major affecting parameter values and the predicted water treatment efficiencies of constructed wetlands with various designs, are expected to give some valuable information for design, construction, manipulation, management, and diagnosis of constructed wetlands in the future.