廢棄活性污泥超音波水解能源化效益之探討

Energy Benefit Analysis of Ultrasonic Hydrolysis on Waste Activated Sludge

邱俊祥(Chun-Hsiang Chiu)

指導教授 ： 莊順興

朝陽科技大學/理工學院/環境工程與管理系/碩士(2009年)

摘要

本研究乃以超音波進行污泥前處理，期能提高後續厭氧消化之固體物去除率、降低厭氧消化停留時間並且增加甲烷產生率。超音波前處理之過程中，能將污泥中的固體性有機物加以破碎，提升有機物被細菌所利用的效益，進而增加甲烷產生率，達到更高的能源化效益。
實驗結果顯示，加鹼併同超音波30 min水解下，不同固含量污泥之單位污泥SCOD溶出量，以TS 4.0%污泥達0.65 gSCOD/gSS溶出量為最佳，TS 2.0%污泥次之，單位溶出量為0.62 gSCOD/gSS，接著為TS 5.0%污泥單位溶出量0.56 gSCOD/gSS，最後為TS 3.0%污泥，其溶出量為0.52 gSCOD/gSS。
由實驗結果得知，相同比能量下，不同固含量污泥所溶出的SCOD效益高低依序為TS 4.0%最高、TS 2.0%次之、TS 3.0%再次之、TS 5.0%最低，四種不同固含量污泥，當比能量超過5 kJ/gTS時，其SCOD溶出效益皆趨於平緩。
能源效益分析顯示，TS 2.0 %污泥在不同負荷下，以超音波10 min、初始負荷[S/X]i=0.5效益最佳，其產電達2.7 kWh/m3，如果將超音波震盪提升為30 min，產電量則上升為3.6 kWh/m3，其提升之效益並不顯著。
TS 3.0 %污泥加鹼併同超音波水解提升之能源效益中，其能源效益以超音波10 min、初始負荷[S/X]i＝0.25下可達到9.1 kWh/m3為最佳，而TS 4.0 %污泥加鹼併同超音波水解提升之能源效益，則以超音波10 min、初始負荷[S/X]i＝0.25下可達到22.8 kWh/m3為最佳效益，但兩者濃度有一共通點，當提升到超音波30 min前處理時，其提升之能源效益卻下滑，由此可知超音波震盪前10 min之效益最佳。

關鍵字

能源效益分析 ； 比能量 ； 廢棄活性污泥 ； 超音波水解

並列摘要

The purpose of this study is to investigate the pretreatment of waste activated sludge by ultrasonic in order to enhance the solids removal of anaerobic digestion. It also reduces the duration of anaerobic digestion and increase the methane production rate. The process of ultrasonic pretreatment can break the solid content of sludge, and promote the organic content be used by bacteria, it increases the rate of methane production as well in order to achieve the higher energy benefit.
The results of experiment find out that hydrolysis with alkali and ultrasonic in 30 mins have different dissolution of sludge with different total solid conted. The best dissolution is TS 4.0%, concentration of 0.65 gSCOD / gSS. TS 2.0% sludge is secondary, the unit of the dissolution is 0.62 gSCOD / gSS, then TS 5.0% sludge that the unit of the dissolution is 0.56 gSCOD / gSS, and the last TS 3.0% sludge, which dissolution is 0.52 gSCOD / gSS.
According to the results, it shows that the different total solid content of sludge demonstrate different dissolution benefit of SCOD under the same specific energy input. TS 4.0% is the highest, TS 2.0% is second, TS 3.0% and TS 5.0% are minimum. When the specific energy more than 5 kJ / gTS, the dissolution benefit of SCOD tend to became gentle.
The analysis of energy benefit indicates that TS 2.0% sludge under different initial organic loading, the effectiveness of initial loading [S/X]i= 0.5 with ultrasound in 10 mins is the best and its benefit 2.7 kWh/m3. However, if the ultrasonic increase to 30 mins, the output rise to 3.6 kWh/m3. The benefit of improvement is not clear.
For TS 3.0% sludge, hydrolysis with alkali and ultrasonic in 10 mins, initial loading [S/X]i= 0.25 can up the efficiency to 9.1 kWh/m3 for the best benefit. Moreover, for TS 4.0% sludge the energy benefit of initial loading [S/X]i= 0.25 loading by ultrasonic in 10 min can rise to 22.8 kWh/m3. The experiment of these two has one point in common: when the pretreatment of ultrasonic increase to 30 min, the energy benefit becomes decline, it shows the best benefits that is the 10 min ultrasonic vibration.

並列關鍵字

Specific energy input ； Energy Benefit analysis ； Ultrasonic Hydrolysis ； Waste activated sludge

參考文獻

Andrews, J. F. Dynamic Model of the Anaerobic Digestion Process. J. SED,ASCE, 95, 95-116, 1967.

Buswell, A. M. and Hatfied, W. D. Anaerobic Fermentation, Bulletin No. 32, Illinois State Water Survey, Urbana, 1939.

Bougrier, C., Carr`ere, H. and Delgenes, J.P. Solubilization of waste-activated sludge by ultrasound treatment, Chem. Eng. J. 106, 163–169, 2005.

Choi, H.B., Hwang, K.Y., Shin, E.B. Effects on anaerobic digestion of sewage sludge pre-treatment, Water Sci. Technol. 35,207–211, 1997.

Cha, G. C. and Tatsuya, N. Effect of Rapid Temperature Change and HRT on Anaerobic Acidogenesis, Wat. Sci. Tech., Vol. 36, No. 6, pp. 247-253, 1997.