垃圾滲出水之化學及活性污泥處理

Combined Chemical and Activated Sludge Treatment of Landfill Leachate

張志成(Chih.C.Chang)

指導教授 ： 林勝雄

元智大學/工程學院/化學工程與材料科學學系/碩士(1998年)

摘要

由於在參研國內外文獻後，得知生物消化、化學及熱破壞、混凝沉澱法、吸附、薄膜技術、氧化還原……等等處理程序中，沒有一個程序是其本身就足以處理滲出水的；因此本研究目標在於找出最適當且經濟可行解決垃圾滲出水之可行途徑。
本實驗將原垃圾滲出水先以化學混凝法將存在於滲出水中之大部分有機物質予以混凝沉澱，由pH值、PAC�polymer的加藥比來探討化學混凝法對滲出水中有機物之化學混凝及脫色之效果；接著藉由批式實驗以探討電芬法處理垃圾滲出水中難分解有機物，由pH值、電極、H2O2加藥量、攪拌速度、H2O2不同加入方式及不同電解型式來探討電芬法對滲出水中難分解有機物之電解氧化破壞及脫色的效果；最後，將電芬水混合一般生活廢水(1：5)，用回分活性污泥法進行最後處理，並以重複操作證明活性污泥可重複利用；垃圾滲出水經此之階段處理，其COD可降至現行排放標準以下(＜100 ppm)，且其去色率在電芬法處理時，已可達透明無色(ADMI值＜25)，因此，本研究針對難以處理之滲出水又提供了一可行的途徑。
另外，在動力學方面，以指數反應動力學討論電芬法中，不同H2O2加藥量下，COD去除過程的一階多段反應，發現第一段是H2O2的氧化混凝作用，第二段是電解的作用。
最後，本實驗針對所取之垃圾滲出水產生的刺激性臭味，以新型除臭劑進行初步除臭處理測試，實驗証明在6分鐘內除臭劑可快速的將臭味完全分解而達到去除臭味的目的。

關鍵字

垃圾滲出水 ； 電芬法 ； 回分活性污泥處理 ； 化學混凝

並列摘要

Past researches have shown that biological treatment, chemical or thermal oxidation, chemical coagulation, adsorption, membrane processes, etc. have been the popular methods employed for dealing with landfill leachate. However, no single technology could offer the optimum solution in dealing with this treatment problem. The objective of this research represents an attempt to identify a potential combination of various methods that is effective and yet economical.
The experimental investigations consist primarily of integrating the chemical coagulation, electro-Fenton method and sequencing batch reactor method into a single process. The chemical coagulation serves as the first treatment step in removing all suspended solids from the raw leachate. The operating variables, including pH, PAC/polymer ratio and the total amount of PAC, were examined to determine their optimum combinations. In the second step, the electro-Fenton (E-F) method was employed for decomposing the refractory organic compounds present in the leachate. The major operating variables of the electro-Fenton method include the pH, electrode material, amount of hydrogen peroxide and the way it was added, stirrer speed, applied current and treatment time. The effects of these variables on the treatment efficiency were thoroughly examined so as to enable determination of optimum combinations. In the last step, the effluent from the electro-Fenton treatment was mixed with sewage wastewater in a ratio of 1:5 and the mixture was then treated using the sequencing batch reactor (SBR) method. The effluent from the integrated treatment method was found to be excellent with a COD concentra-tion much less than 100 mg/l and ADMI (color index) less than 25.
Kinetic studies on the electro-Fenton method were conducted also. Under condition of varying H2O2 amounts, the COD removal found to follow a two-stage, first-order kinetics. The first stage was basically oxidation by H2O2 and chemical coagulation and the second one was electrical oxidation.
In the last part of this work, preliminary deodorizing tests of the raw landfill leachate were made using a new type of deodorizing agent (commercial name Magic). Experimental tests conducted in a small closed space revealed that in just 6 min, the agent was able to remove practically all odor of air generated by the leachate.

並列關鍵字

landfill leachate ； electro-Fenton ； sequencing batch reactor ； chemical coagulation

參考文獻

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