垃圾滲出水之綜合化學和生物處理

Combined Chemical and Biological Treatments of Landfill Leachate

鄭國威(Kuo W. Cheng)

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(2000年)

摘要

從早期的衛生掩埋法，到現今流行的焚化法，不論採用何種垃圾清運處理方式，皆會產生成分複雜不易分解的高濃度垃圾滲出水。由於垃圾滲出水組成複雜，幾乎沒有一種程序可以單獨處理，本研究結合了數種物理、化學及生物處理程序，可有效去除垃圾滲出水中的污染物質。
在垃圾滲出水前處理的部分，先以化學混凝法將垃圾滲出水中大部分的懸浮物及有機物予以混凝沉澱，影響化學混凝法效果的重要操作變因有pH值、PAC的加藥量及PAC/Polymer的比值。經由pH值、PAC的加藥量及PAC/Polymer的加藥量的改變來探討化學混凝法對滲出水中有機物質及色度之去除效果。
將前處理後的垃圾滲出水導入催化氧化反應器，在此一處理程序中活性碳纖維與臭氧可共同處理廢水中不易分解的物質，藉由改變不同臭氧通量及活性碳纖維填充量，探討催化氧化法對滲出水中難分解有機物之氧化破壞及脫色之效果；在理論方面，一階多段、通式、複式反應動力學模式皆可適切模擬滲出水中有機物之去除速率。
在最終處理的部份，期望藉由回分法可以使得垃圾滲出水水質達到排放標準。經過回分法處理後，COD值可降至現行排放標準以下(<100 mg/l)。在回分法的生物反應理論方面，藉由Eckenfelder所提出的完全混合動力學模式(Completely Mixed Kinetics Model),可得知不同水體間的生化反應速率常數k與不可生物降解物質的濃度有明顯的不同。

關鍵字

垃圾滲出水 ； 化學處理 ； 生物處理 ； 連續回分法

並列摘要

Leachate is a common liquid wastewater that is generated in a landfill site or municipal solid waste incinerator. Due to its complex characteristics and presence of many non-biodegradable substance, treatment of the landfill leachate has never been easy. The purpose of this work is to experimentally investigate several combined physical, chemical and biological methods for dealing with this particular type of wastewater.
Chemical coagulation was adopted as a pretreatment of the raw landfill leachate. Test results have indicated that removal of suspended solids, color and some inorganic and/or organic compounds is quite good. The important operating variables of chemical coagulation included the initial pH, PAC/polymer ratio and the amount of PAC. Based on the test results, appropriate operating conditions of these variables were established for efficient operations.
After chemical coagulation, the landfill leachate was treated by catalytic oxidation in a gas-induced reactor. In this chemical treatment, activated carbon fiber was employed, in conjunction with ozone, as a catalyst in oxidizing the recalcitrants in the wastewater. The test result of catalytic reaction was modeled using various kinetics, including first-order/multi-step, generalized and complex models. The models parameters were established by best fit of these models to the observed data.
In the last of treatment train, sequencing batch reactor (SBR) was employed to further elevate the water quality of the landfill leachate to the discharge standards. The leachate after SBR treatment was clear with low COD below 100 ml/l. A Eckenfelder kinetics of completely mixed type was adopted to model the biological reaction of the SBR process and the parameters of the model were empirically identified.

並列關鍵字

Chemical Treatments ； Biological Treatments ； Landfill Leachate ； CSBR

參考文獻

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