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年度	102	專案性質	實驗性質
專案類別	研究專案	研究主題	底泥
申請機構	國立高雄第一科技大學	申請系所	環境與安全衛生工程系
專案主持人	陳勝一	職等/職稱	教授
專案中文名稱	重金屬污染底泥整合性生物復育技術之效能提昇及系統改善
中文關鍵字	底泥；重金屬；生物復育；硫氧化菌
專案英文名稱	Performance enhancement and system improvement of the bioremediation technology for sediments contaminated by heavy metals
英文關鍵字	Sediment; Heavy Metal; Bioleaching
執行金額
執行期間	2012/12/10 至 2013/12/9
計畫中文摘要	在河川污染整治過程中，除污染源管制及興建下水道系統之外，底泥疏浚通 常亦是整治方案之一。底泥因已承受相當程度之污染物，疏浚後之污染底泥需經 適當處理及處置，才可達到不造成二次污染之目標。由於目前國內針對受污染底 泥處理技術之研究較少，未來極需要此方面之技術，以處理疏浚後之大量底泥。 但是，污染底泥量增加、處理費用升高，加上更嚴格之法規管制要求，以致於未 來底泥之處理與處置技術將必須脫離傳統方法並且重新調整，始能因應實際之需 要。在自然界之硫生物循環中，對於環境生物技術之開發及應用，蘊藏著之無限 生機。一般在硫之生物循環中，除硫化合物之型態有所轉變外，通常亦含會牽涉 到重金屬、有機物或氮於自然或人為生態系統中之轉變與移動。因此，若能將硫 細菌之生理代謝能力善加利用，應用硫生物循環於環境生物技術中，對於生物科本研究之主要目標為利用硫生物循環中之硫氧化作用，發展出一套可應用於 處理重金屬污染底泥之整合性環境生物技術，以達污染預防與資源循環再利用之 目的。本計畫之主要研究重點首先在於針對前一年度所建立及求得之氣提式生物 溶出技術的最佳化操作參數進行連續式重金屬污染底泥生物處理程序之開發；另 外，本研究中同時將以零價鐵流體化床處理生物溶出技術中所產生之金屬廢液， 並探討主要操作參數對於零價鐵流體化床技術處理金屬廢液之影響，以決定最佳 之操作參數，最後希望能生物溶出技術及零價鐵流體化床技術結合發展為一套經 濟且實用之整合性生物復育技術用以有效處理重金屬污染底泥，並且以真正達到 污染防治之目的。經研究發現，水力停留時間增加時，反應槽中之處理負荷降低， 硫氧化菌之活性較佳，使得底泥中有較高之重金屬溶出效率。當水力停留時間設 定為 10 天時，在連續式生物溶出程序中銅、鋅及鎳之溶出效率最高可以達到 52% ~ 60%、60% ~ 70% 與 62% ~ 70%，而鉻並無明顯之溶出效率。在連續式生物溶 出程序中，增加植種量可能造成反應槽中微生物之活性降低，進而導致底泥中重 金屬之溶出效率並無有效提昇之情形。另一方面，本研究之零價鐵處理金屬混合 廢液實驗中，零價鐵添加量之最佳操作值應設定為 10 ~ 20 g/L，而重金屬初始濃 度分別設定於銅 3 mg/L ~ 10 mg/L；鋅 7 mg/L ~ 20 mg/L；鎳 2 mg/L ~ 4 mg/L 及 鉻 0.3 mg/L ~ 1 mg/L 之間時，混合廢液中銅、鋅、鎳及鉻分別有 98%、20%、25% 及 90% 以上之去除效率。
計畫英文摘要	In the restoration strategies of river and lake, besides controlling pollution sources and building sewer system, dredging of contaminated sediments from the rivers or lakes should be one of the important issues. Most of contaminated sediments often contain high content of heavy metals and thus can not be disposed of on the land without proper treatment. However, there are now relative few researches for detoxification and decontamination processes of heavy metals in contaminated sediments in Taiwan. In future, it is very important to develop the techniques for treatment of the large quantity of contaminated sediments in the remediation of contaminated rivers or lakes. Sulfur cycle conversions do not only involve the elemental sulfur, but also directly influence organic matter, nitrogen and heavy metal conversions and fluxes within natural or man-made ecosystems. Therefore, one can also use the sulfur cycle as the driving force behind some specific related environmental biotechnological applications. Sulfur-oxidizing bacteria utilize reduced sulfur as an energy source for chemolithotrophic growth, producing soluble metal sulfates and sulfuric acid. A bioleaching process uses these biological oxidation processes of sulfur-oxidizing bacteria to remove and concentrate metals from polluted sediments, soils or solid waste. The purpose of this study is to develop a continuous bioleaching process for sediments contaminated by heavy metals based on the research results and findings obtained from the previous year’s project. The optimal parameters and performance enhancement of the above bioleaching process were investigated in this study. Meanwhile, the fluidized bed reactor with zero-valent iron (ZVI) was applied for treatment of the metal-containing solution produced from the bioleaching process. The operating factors, including dosage of ZVI and initial concentration of heavy metal, affecting the removal efficiency of heavy metals by ZVI in the metal-containing solution were examined in this project. The results showed that the pH, sulfate concentration and metal solubilization can reach the steady state after 3 hydraulic retention times (HRT) of continuous operation. At the HRT of 10 days, the maximum efficiency of heavy metals solubilized from the sediment was 52%-60%, 60%-70%, and 62%-70% for Cu, Zn and Ni, respectively. Meanwhile the efficiency of Cr solubilization was below 6%. The efficiency of heavy metals leached from sediments in this continuous bioleaching process was not enhanced by increasing the inoclum. On the other hand, the results of response surface methodology indicated that the maximum efficiency of metal removal from the bio-leachate solution was achieved at 10-20 g/l of zero-valent iron (ZVI) dosage with 3-10 mg/l of Cu, 7-20 mg/l of Zn, 2-4 mg/l of Ni and 0.3-1 mg/l of Cr, respectively, where up to 98%, 20%, 25% and 90% of Cu, Zn, Ni and Cr were removed from the bio-leachate solution.