下水污泥前處理減量技術比較之研究

A Study of Multi-pretreatment Technologies for Sewage Sludge Reduction

陳俞穎(Yu-Ying Chen)

指導教授 ： 張添晉

國立臺北科技大學/工程學院/環境工程與管理研究所/碩士(2008年)

https://doi.org/10.6841/NTUT.2008.00557

摘要

為提升國民良好生活環境，國內積極推動發展污水下水道之建設，污泥產量隨之增加。本研究比較超音波及臭氧前處理技術，結合歐美及日本先進國家之已開發高溫嗜熱菌污泥減量技術，比較此兩項前處理技術及結合嗜熱菌消化減量技術之研究。
超音波及臭氧化前處理之特色為，將污泥膠羽破壞使顆粒變小，提升較難溶出之有機質溶出速率，減少消化時間及剩餘污泥產量。將下水污泥予以超音波水解及臭氧化處理之目的，在於提升後續高溫好氧消化之污泥減量效率。高溫好氧消化技術具備下列幾項特點：(1)使有機廢棄污泥之產量大幅降低；(2)縮短污泥停留時間；(3)對致病菌具有殺菌之能力。其處理方式為將經前處理之污泥迴流至高溫好氧反應槽內，以提高污泥之生物可降解性，利用嗜熱菌產生水解酵素將膠羽結構複雜之大分子分解，溶化為易於微生物利用之小分子。
本實驗分為兩階段進行研究，分別將污泥利用超音波及臭氧前處理，找出最佳破壞效率，第二階段將經前處理之污泥，分別進入高溫好氧消化及常溫好氧消化進行污泥減量。
經由本實驗結果得知超音波水解時間30分鐘，比能量(Es)為397 kJ/gSS，CODs溶出率可達44.4％，臭氧投入劑量為0.34 gO3/gSS，CODs溶出率可達15.5％，相較未經前處理之污泥具有細胞壁破碎效果。第二部分進行高溫好氧消化實驗，污泥停留時間長達15天時，污泥未經前處理給予高溫好氧消化，其VSS平均去除率為53％；經超音波前處理給予高溫好氧消化，可將SRT縮短至3天，去除率高達55％；經臭氧前處理給予高溫好氧消化，SRT可縮短至9天，去除率為55％；證明污泥經前處理可提升後續嗜熱菌消化效率，結果顯示本實驗下水污泥經超音波水解及臭氧化前處理，進行高溫好氧消化可得到良好減量效果。

關鍵字

下水污泥 ； 超音波水解 ； 臭氧處理 ； 高溫好氧消化 ； 嗜熱菌

並列摘要

In order to improve environmental quality, Taiwan’s government makes more effort on building sewerage systems construction. These operating sewerage systems will lead to an important increase in sewage sludge production .Due to the limitation of landfall site, sludge disposal will become a hot issue in the future. The focus of this study was to carry out the comparison of the ultrasounds and ozonation technologies integrated with thermophilic aerobic digestion process. Two pretreatment processes for reduction efficiency are been discussed.
The aim of ultrasounds and ozonation is to solubilise and/or to reduce the size of organic compounds, and specially refractory compounds, in order to make them more easily biodegradable. Final quantity of residual sludge and time of digestion can thus be reduced. The objective of pretreatment is to increase reduction efficiency of thermophilic aerobic digestion. The characteristics of thermophilic aerobic digestion process include three parts: (1) increase in organic sewage sludge reduction (2) sludge retention time can be reduced (3) biosolids may be totally contained until they are stabilized. In this process, the excess activated sludge in returned sludge is solubilized with enzyme secreted from the thermophilic bacteria in the S-TE reactor. This enhances the bio-degradability of the returned sludge. The solubilized return sludge is then decomposed and mineralized by activated sludge microorganisms in aeration tank.

The experiment includes two parts：the first is pretreatment of sludge using ultrasounds and ozonation , and find out the efficiency of disintegration cell well. The other is put pretreatment of sludge using ultrasound and ozonation in the thermophilic aerobic digestion reactor and aerobic digestion reactor, respectively.
The results showed that dissolved COD rate of 44.4％ for sonication within a duration of 30 minutes(Specific energy is 397 kJ/gSS). The right dose of ozone is 0.34 gO3/gSS that dissolved COD rate until 15.5％. Effect of sludge cell wall efficiency of disintegration, sonication and ozonation pre-treatment was better than non-pretreatment. The SRT was 15 days of thermophilic aerobic digestion, non-treatment sludge of VSS reduction efficiency is 53％. Ultrasounds sludge of SRT can be reduced to 3 days, VSS reduction efficiency is 55％. Ozonation sludge of SRT can be reduced to 9 days, VSS reduction efficiency is 55％.
Overall sludge pretreatment by ultrasonic and ozonation to integrate thermophilic aerobic digestion is positive. The results showed that sewage sludge using pretreatment technologies should increase digestion efficiency of thermophilic aerobic digestion. The results showed that sewage sludge using pretreatment with ultrasonic and ozonation had a good reduction efficiency on thermophilic aerobic digestion process.

並列關鍵字

Sewage Sludge ； Ultrasounds ； Ozonation ； Thermophilic Aerobic Digestion ； Thermophilic Bacteria

參考文獻

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