批式活性污泥處理高酚濃度廢水之研究

Biodegradation of High Phenol Concentration Wastewater by Activated Sludge in a Batch Reactor

在處理大量含酚廢水時，以生物處理較具經濟性，且具有完全分解與礦化成對環境無害與負擔之物質，減少污泥或二次污染物的特性。但對於高濃度含酚廢水，生物處理最大缺點是酚對微生物生長之抑制性，即使是以酚為能源與碳源之微生物在高濃度亦受到抑制，對微生物本身也是一種毒性。本研究以批式活性污泥法，測試未馴養及已馴養活性污泥對'降解含酚廢水之差異性。於150mgL^（-1）低酚濃度廢水，在不同活性污泥濃度下，未馴養汙泥對於酚降解所需時間有顯著差異，即提高污泥濃度可降低降解所需時間，但對於已馴養汙泥則無明顯差異；然而在2000 mgL^（-1）高酚濃度時，對於已馴養汙泥則隨著污泥濃五度提高，可降低所需降解時間。為模擬薄膜生物反應槽法，提高污泥濃度至8000 mgL^（-1），測試不同酚濃度之降解時間。發現兩者對高達3000 mgL^（-1）酚濃度均可降解，但已馴養活性污泥相對可較快速完全降解，以2000 mgL^（-1）為例，只需50小時，而未馴養則需80小時；本研究得到降解高酚濃度廢水所需時間，可做為未來設計連續流薄膜生物反應槽處理高酚濃度廢水之水力停留時間的初步參考。

In the treating of large amount of phenolic wastewater, biological treatment would be more economical and less sludge production. Also phenol could be completely decomposed into substances that are harmless to the environment. The main shortcoming of biodegradation of high concentrated phenol wastewater would be the inhibition of phenol to the growth of micro-organism even though phenol is the only carbon and energy source. The biodegradation of phenolic wastewater by activated sludge in a batch reactor was studied. At low phenol concentration 150 mgL^（-1）, with different MLSS concentration, there was a difference in the degradation rate by raw activated sludge. However, this was not observed in the case of the acclimatized activated sludge. But at high phenol concentration 2,000 mgL^（-1）, this trend was again observed. To simulate the concentration of MLSS in membrane bio-reactor, raised the MLSS concentration to 8,000 mgL^（-1） to investigate the effect of phenol concentration on the degradation rate. It was found that even at the concentration 3,000 mgL^（-1）, phenol could be decomposed at both cases of raw and acclimatized sludge. Apparently, acclimatized sludge had a higher rate than that of raw sludge. In the case of 2,500 mgL^（-1）, the decomposition time by acclimatized sludge was only 50 hours which is short than 80 hours by raw sludge. This outcome could be useful for the rational design of a continuous membrane bioreactor to treat the high phenol concentration wastewater.