結合臭氧氧化法與生物整治法降解通氣層機油污染物

Combined Ozone Oxidation and Bioremediation for the Degradation of Motor Oil Contaminant in Vadose Zone

蕭忠明(CHUNG-MING HSIAO)

指導教授 ： 劉敏信

朝陽科技大學/理工學院/環境工程與管理系/碩士(2020年)

摘要

本研究結合臭氧氧化法及生物整治法降解通氣層機油污染物，試驗過程中將臭氧注氣於受機油污染之土壤中，作為預臭氧 (Pre-ozonation) 程序降解污染物，透過以上兩種技術整治列車的結合，可使污染物達到更良好的處理成效。在化學氧化的過程中，臭氧氧化法增加污染物的生物降解性，一般是透過臭氧將大分子的有機化合物斷鍵成較小分子的化合物，以利微生物分解。本研究在臭氧注氣試驗後定期監測預臭氧後土壤之 pH 值、導電度、氧化還原電位等基本性質，評估開始進行生物復育步驟的適當時間，在使用臭氧注氣法進行批次試驗後，開始進行微生物整治，使其達到最佳的處理成效，並節省臭氧使用量及生物降解時間。
本研究自行製備通氣層受機油污染濃度約為 12,000 mg/kg 之土壤模場，利用臭氧注氣法 (Ozone Sparging) 結合生物整治法 (Bioremediation) 搭配氣泡式微生物呼吸儀監測微生物於模場內之活性狀況，並探討機油污染物降解成效。本研究將含臭氧的空氣流量設定為 10 L/min、臭氧流率為 2,888 mg/min 之條件，分別以每批次 1 小時注入兩個不同土壤含水率的臭氧模場中，研究結果顯示將臭氧注氣於高土壤含水率 15% 的模場至第 12 批次時，降解率為 47%；而在低土壤含水率 1% 情況下的模場其臭氧注氣至第 4 批次時降解率已高達 75%，當低含水率的臭氧模場注氣試驗到第 4 批次時已達臭氧降解極限，後續通入之臭氧無明顯降解成效。將預臭氧過後第 0、3、6、9、12 批次之高含水率土壤於臭氧模場中取出進行生物復育之步驟，研究結果顯示經預臭氧過後之污染土壤皆可提高生物降解率，而在高含水率的土壤經過預臭氧過後至第 12 批次時，可將生物降解率由 59% 提升至 94%，而低含水率的土壤經過預臭氧過後，各批次之試驗土壤皆已經可達到法規標準 1,000 mg/kg 以下，顯示出極佳的降解成效。本試驗亦藉由微生物氣泡式呼吸儀觀察微生物活性狀況，得知微生物於預臭氧過後之土壤模場中有較佳的微生物攝氧情形，與未臭氧注氣之模場相比顯示有較佳的微生物活性狀況。

關鍵字

化學氧化法 ； 機油降解微生物 ； 整治列車

並列摘要

The treatment methods used in this study was to combine the two techniques, ozone sparging and biodegradation, as a remediation chain in order to achieve degradation of motor oil in vadose zone. During chemical oxidation process, ozone degraded contaminants into by-products that were more toxic, affecting the survival of the planted microorganisms. However, chemical oxidation by ozone increased the biological degradability of contaminants. This was achieved through large macromolecular organic compounds being degraded into chains of smaller compounds by ozone to be degraded by microorganisms. The current project regularly monitored pH values, conductivities and ORP values of the pre-ozonated soil, in order to assess the optimal starting time for bioremediation. Batch experiments were conducted after ozone sparging, followed by bioremediation, so as to attain optimal treatment results, saving ozone usage and degrading time.
A batch-type ozone sparging method was used to treat the motor oil contaminated soil, the ozone flow rate was set up at 10 L/min with ozone concentration 288.8 mg/L, the sparging time was one hour each batch and ozone was sparged into two pilots with 1% and 15% water content in soil respectively. The results showed that the removal efficiency of motor oil contaminant was 47% when 12 hours pre-ozonation was applied in 15% water content soil. Meanwhile, the removal efficiency approached 75% when 4 hours pre-ozonation was applied in 1% water content soil, no obvious removal efficiency increased for further pre-ozonation. In addition, the soil samples were collected after 3, 6, 9, 12 hours ozone sparging for biodegradation test by using the implanted strain Pseudomonas aeruginosa. The biodegradation was enhanced when pre-ozonation was applied in both soil layer pilots, the biodegradation efficiency increased from 59% to 94% in higher soil water content, however the remaining concentration of total petroleum hydrocarbons reached below 1,000 mg/kg the regulation standard in lower soil water content. The accumulative oxygen uptake of microbe increased which indicated the microbes was activated in pre-ozonation soil.

並列關鍵字

Chemical oxidation ； Motor oil degrading microorganisms ； Remediation chain

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