Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/4981
標題: 受多環芳香族碳氫化合物─、菲污染土壤之生物復育研究
作者: 邱明良
關鍵字: naphthalene;;phenanthrene;bioremediation;respirometer;soil column;菲;生物復育;呼吸儀;土壤管柱
出版社: 環境工程學系
摘要: 
本研究主要目的在探討受PAHs污染土壤採用生物復育之可行性,針對其中二環之及三環之菲分子加以研究,並以氣泡式呼吸儀偵測其在土壤中好氧分解所需之耗氧量,推估其生物降解效率及生物活性。
由結果可知,由馴養之chemostat分離出三株能降解之菌株,依次命名為N-2、N-4及N-5菌。其中以N-4菌降解土壤中之能力最好,其次分別為N-2菌及N-5菌。當混合菌種和僅有單一菌株存在時,降解土壤中之並無顯著不同,混合族群若有N-4菌存在於土壤中,其降解狀況最好,N-4菌於降解方面扮演了關鍵性角色。N-4菌經由PCA 增殖,加入土壤中後做為生物復育菌種,其在土壤環境適應能力極佳,且當土壤中濃度達1000 μg/g-soil對於N-4菌並不會產生抑制作用,擬零階反應速率常數可達2.11 μg/g-soil-hr。添加於土壤中之溶液或無機鹽之pH值介於3~11時,對於N-4菌降解土壤中之影響不大。
利用混合菌對於土壤中之菲加以降解,若能添加足夠量之微生物量,對於菲之降解有促進作用。現地菌也能夠有效地利用土壤中之菲做為碳源及能源,但當土壤中之菲濃度達300 μg/g-soil時,添加馴化菌種於土壤中並沒有任何促進之作用。添加馴化菌會對於現地生物降解土壤中菲之總量產生了抑制作用,未添加馴化菌之現地微生物組可將菲降解至更低程度。重複添加具有活性之馴化菌,可達到完全復育受菲污染土壤之目標。存在情況下,可促使土壤中之菲能夠更快被微生物所利用,且當土壤中菲濃度為200 μg/g-soil時,濃度為300 μg/g-soil效果最佳。
以呼吸儀測定土壤中生物降解所需之耗氧量,於60 %WHC情況下,實際耗氧量與理論耗氧量之比值介於0.62~1.23之間,利用氣泡式呼吸儀之方式是可行的,而階梯狀之累積耗氧圖的成份原因不詳有待未來研究加以探討。利用土壤管柱來加以模擬土壤生物通氣法之情況,實際耗氧量與理論耗氧量之比值介於0.75~0.85之間,而反應器有持續漏氣之情況,造成結果誤差仍待將反應器重新設計來加以探討。

The objective of this study was to discuss the feasibility of contaminated by naphthalene- or phenanthrene-contaminated soils. A respirometer was used to measure the oxygen demand during the process of biodegradation in soils. The biodegradation rate and microbial activity were also studied by the repirometer.
Three strains named N-2、N-4 and N-5 were isolated from chemostat which was acclimated by both naphthalene and phenanthrene. The strain N-4 had the best biodegradable capacity for removal of naphthalene, the next was the strain N-2 and N-5. The biodegradation of naphthalene in soils inoculated by pure-culture and mixed-culture had a similar result. When the strain N-4 was in the mixed-culture, the strain N-4 played a key role for the removal of naphthalene and it had the highest biodegradation performance. The strain N-4 that was used as the cell source was collected from PCA (Plate Count Agar). These cells could be acclimated in the soil environment very quickly. When the concentration of naphthalene reached 1000 mg/g-soil, the inhibition effect was not observed. The simulated zero-order biodegradation rate constant was 2.11 mg-Nap/g-soil-hr. The pH of inorganic nutrient solution added to the soil was in the range of 3~11 did not have significant effects on the biodegradation of naphthalene.
The biodegradation of phenanthrene was studied by a mixed culture. The biodegradation of phenanthrene was promoted through the addition of degraders. The indigenous cells in soil also had contribution on degradation of phenanthrene. When the concentration of phenanthrene reached 300 mg/g-soil, addition of acclimated cells did not enhance biodegradation of phenanthrene. And addition of acclimated cells resulted in a decrease in the total amount of phenanthrene degraded, the indigenous cells in soil could degrade phenanthrene to reach a much lower concentration. Repeat addition of active acclimated cells reached the goal of complete bioremediation of phenanthrene in soils. The present of naphthalene increased the removal rate of phenanthrene. When the concentration of phenanthrene was 200 mg/g-soil, the present of naphthalene at 300 mg/g-soil had the best enhancement on the phenanthrene removal.
The oxygen demand consumed by biodegradation of naphthalene in soil was recorded by a respirometer. Under 60 % WHC, the ratio of the result gained from respiration study to the result calculated from McCarty''s stoichiometry equation was in the range of 0.62~1.23. The respirometer could be used to measure the oxygen demand for the biodegradation study in soils. A soil column was designed to simulate soil bioventing, the ratio of the actual oxygen demand to the theoretical value was in the range of 0.75~0.85. Air leakage was found in the soil column experiment resulting in a difficult to explore the result. The soil column was needed to redesign to study the soil bioventing in the biodegradation process.
URI: http://hdl.handle.net/11455/4981
Appears in Collections:環境工程學系所

Show full item record
 

Google ScholarTM

Check


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.