聚乙二醇PEG被大量應用於再生能源太陽能板的製程中，作為研磨晶圓板潤滑液的主要成分，PEG的難分解性和親水性使得晶圓廠洩放廢水中COD值過高，雖然晶圓廠針對洩放廢水評估許多物化和生物處理單元，希望降低洩放廢水中的COD，但除了處理成效不盡理想之外，也因經濟層面考量而無法於實場上應用；故洩放廢水COD值仍高達1000~1500 mg/L，無法符合晶圓廠的COD放流水標準100 mg/L。故本研究致力於研究一套能有效處理含PEG廢水的操作單元，並將此單元的操作成本降至最低。 經由參考文獻的研讀可以得知PEG以濕式氧化法WAO、H2O2/UV等高級氧化處理程序降解後，除了可以礦化去除PEG之外，亦可提高PEG的生物降解性；但是因為其不經濟且耗能的缺點，所以無法於實場上應用。針對此一缺點，本研究改以具有能源消耗低及操作簡便優點的Fenton氧化來處理PEG，以Fenton產生的氫氧自由基將PEG分子鍵結破壞。如此一來不僅可以達到WAO的處理效果，也可解決WAO處理程序的缺點。 經由Fenton處理後的PEG水樣其生物降解性指標可大為提升，BOD/COD可由原先的0提升至0.5；此結果顯示PEG經由Fenton處理後，即可以好氧微生物進行降解，有效的解決晶圓廠放流水中COD值過高的問題。 PEG (Polyethylene glycol) is applied extensively in the manufacturing process of solar panels as liquid lubricant. Due to recalcitrant and hydrophilic characteristics of PEG, wafer factory are constantly struggle of meeting discharge limit for COD. COD value of the dicharge wastewater can reach as high as 1000~1500 mg/L and is much higher the effluents standard of 100 mg/L set by Taiwan EPA. Although wafer factories have assessed many physico-chemical and biological processes for wastewater treatment, treatment efficiencies of these processes are not as promising as they expect. In addition, the processes can’t be applied for actual operation because of the economic considerations. Past studies showed that PEG can be degraded by using advanced oxidation processes such as wet oxidation WAO and H2O2/UV. The advanced oxidation processes can not only mineralize but also increase the biodegradability of PEG; however, these AOPs are too energy-consuming to be practically employed in actual treatment. Thus, this study would adopt Fenton process to oxidize PEG, taking the advantages of Fenton such as low energy consumption and easy operation. Hydroxyl radicals generated from Fenton would oxidize PEG’s molecular bond, achieving the same effect as WAO without the energy-consuming problem of WAO process. After PEG treated by Fenton, its biological degradability indicated by BOD/COD ratio significantly increased from 0 to 0.5. The result showed that after Fenton pretreatment PEG can be degraded by aerobic biological treatment, and Fenton process followed by aerobic biological treatment can be an effective solution for wafer factory effluents with excessively high COD value.
