以Rhodococcus erythropolis NTU-1復育受正十六烷污染之土壤

Abstract

本研究主要利用菌株Rhodococcus erythropolis NTU-1的生物降解及包覆聚集能力來處理土壤中碳氫化合物。主要研究目的為探討以批式操作的方式培養，並且探討在固相中可能殘有的不可逆吸附的量值以及在固相中和液相中的特殊吸附平衡關係，並且去探討菌株最適當的培養條件，即是能夠有包覆現象產生的濃度範圍。實驗結果發現，會有結塊現象產生主要都是發生在初始添加量為400到1500 μL之間，即是液相中濃度介於1400 μL/L及6600 μL/L之間，其中液相濃度低於1400 μL/L可能會產生黃色片狀的型態，而高於6600 μL/L則可能會因為正十六烷太多而無法順利結塊。

本實驗並比較不同環境因子例如pH值及溫度後土壤中不可逆吸附量值的改變，以及探討了不同情況下得到的吸附等溫線。利用獲得的吸附等溫線，能夠藉由測量液相中的正十六烷濃度即可預測殘存在土壤中的正十六烷的量，並且估算出我們生物在這個系統中的處理效果。經過108小時的批式迴旋培養，即可去除土壤中超過80%的正十六烷的量。 綜括上述，以NTU-1處理在土壤中的油污的效果，是具有相當的潛力以及發展性。

Pure culture of Rhodococcus erythropolis NTU-1 was utilized to test the biodegradability and bioflocculate formation in treatment of petroleum pollutant in the soil. This study evaluated the cultivation in batch system, and discussed the irreversible adsorption of n-hexadecane and special equilibrium between solid phase and liquid phase. We also tried to find the optimum amount of n-hexadecane in our batch system was about 400-1500 μL/ 100mL MSM for NTU-1 consumption. The concentration was about 1400-6600 μL/ L in liquid phase. It means that NTU-1 would trap n-hexadecane in biofloccules. If the concentration in liquid phase was less than 1400 μL/L, the morphological structure may be flakes; if the concentration in liquid phase was more than 6600 μL/L, there might be too much n-hexadecane in the medium to form bioflocculate formation. In this study, we also evaluated different environment factors affecting the irreversible adsorption of n-hexadecane, including pH, temperature, salinity and aging. Different adsorption isotherm would be found by regression. By using the adsorption isotherm we got, we could estimate the n-hexadecane amount in soil by analyzing the concentration in the liquid phase. We could also estimate the biodegradability by NTU-1. Under the optimal condition, NTU-1 could remove more than 80% out of n-hexadecane after 108 hours incubation. To sum up, NTU-1 provided a feasible and potential method to treat contaminated soil in the batch system.