摘要: | 中文摘要 台灣地區隨著經濟的高度發展以及工商業活動的頻繁,都市生活污水的排放量將會逐年增加,政府想逐年提高下水道普及率3%,下水道普及率的提高將會衍生出污泥處理的問題。根據歐陽嶠暉教授(1998)的調查報告指出至2003年都市污水處理廠每天將產生18萬立方公尺的污泥量。到2009年污泥量將成長至每天40萬立方公尺。如此龐大的污泥量,必須妥善的處理和處置,否則將形成嚴重的環境負荷。 本研究採用高壓裂解程序處理都市下水污泥,探討溫度、時間與壓力等操作條件對下水污泥裂解後固體、液體及氣體產物之影響。實驗結果顯示,下水污泥在裂解過程會降低有機物含量且重金屬有濃縮現象,此現象隨著裂解溫度和裂解時間的增加而更加的明顯,和裂解壓力則無明顯之關係;下水污泥裂解後的液體產物種類繁多且複雜,以鏈狀脂肪族與環狀芳香族或環烷類為主;對下水污泥的液體與氣體產物而言,在較低溫時(如400ºC及450ºC)以直鏈脂肪族為主,而在較高溫時(如500ºC)則有多種芳香族及環狀有機化合物。在氣體產物上,所有的氣體濃度隨著裂解溫度之增加而增加,裂解壓力與氣體濃度呈負相關,但丙烯與正丁烷例外。 Abstract With continuing economic growth and industrial development, the population served by the sewer system has been increasing in Taiwan. To promote the service popularity, a "Sewer System Development Plan" has been launched, aiming at an 3% annual service increase. It is estimated that the daily generation of sewage sludge will amount to 400,000 cubic meter by the year 2009, as reported by Ouyang (1998). This substantial amount of sewage sludge will require proper treatment, disposal, and/or recycling. This study investigated the treatment characteristics of sewage sludge, using a high-temperature, high-pressure pyrolysis process, with a focus on the effects of operational parameters, such as the pyrolysis temperature, pressure, and duration, on the properties of the pyrolysis products. The organic contents in the residues, accordingly, were decreased after pyrolysis. However, heavy metals with refractory volatility were concentrated. The results showed that at 400-450ºC, the main products in liquid and gaseous products were aliphatic compounds, whereas at 500ºC, various aromatic and naphthene organic compounds dominated. Most concentration of gaseous products increased with increasing temperature, but decreased with increasing pressure, with the exception that Propylene and Butane products increased with increasing temperature. |