畜牧污泥厭氧消化對溫室氣體減量之評估

Abstract

99年度「畜牧場減廢與資源利用研究」計畫，子計畫五「畜牧污泥厭氧消化對溫室氣體減量之評估」，發現傳統三段式廢水處理技術對營養鹽 (氮、磷) 無去除功能，而 1 Kg 氮約同等 50 Kg CO<SUB>2(eq)</SUB> (30~70 Kg CO<SUB>2(eq)</SUB>)，導致其放流水溫室氣體排放潛勢主要來自於氮源；因此，除氮不僅可使放流水水質提升，且可提升水回收再利用之價值，更可削減溫室氣體排放潛勢。厭氧氨氧化 (ANAMMOX, anaerobic ammonium oxidation process)，係以厭氧氨氧化自營菌於厭氧狀態下，直接轉換氨氮為氮氣，相較於傳統硝化脫硝ANAMMOX 更具處理及經濟效益。本計畫目的係以厭氧氨氧化處理畜牧廢水，除氮以降低溫室氣體排放，提升放流水回收再利用之價值。本計畫擬設置連續批次反應槽 (sequential batch reactor, SBR) 進行實驗。研究成果可提供政府及養豬業者參考。

The results obtained from the previous project (2010) "Assessment of Greenhouse Gases Emission Reduction from Anaerobic Digestion of Livestock Sludges" show that the GHGs emission potential of the effluent was mainly from the nitrogen source (TKN). Thus, the wastewater treatment plant should be upgraded to achieve the nitrogen removal. Anaerobic ammonium oxidation process (ANAMMOX), a noval process, directly converts ammonium nitrogen to nitrogen gas under anaerobic condition. The objective of this project is to develop an Anammox sequential batch reactor for the cost-effective treatment of ammonium from livestock wastewater. The antipated results will be valuable references for livestock wastewater treatment plant to achieve the nitrogen removal as well as to reduce GHGs emissions from livestock wastewater treatment plant.

The emissions of greenhouse gases (GHGs) from livestock wastes (including wastewaters) are becoming significant energy and environmental issues in the world. Agricultural and livestock wastes in Taiwan have been recognized as the most abundant organic wastes. The potential of methane generation from livestock manure management in Taiwan during the period of 1995-2007 has been estimated to range from 36 to 56 Gg/year. Based on the characteristics of swine manure, the maximum potential of methane generation could reach to around 400 Gg/year. Currently, the piggery wastes from hog farmers are mostly treated by the three-step wastewater treatment. It generates large amount of sludge at wastewater treatment plants. Handling and disposal of sludge need considerable attention because of its high organic content. To prevent emissions of greenhouse gases (GHGs) to the natural environment it is necessary to develop an optimal recycling biotechnology from production to utilization. Biogas production from anaerobic digestion of livestock sludge and slurries is an effective way of reducing greenhouse gas emissions. The purpose of the proposed project is to evaluate the potential of using anerobic biotechnology for converting livestock sludge into biogas and reducing emissions of GHGs. This project is forcused to investigate the production and characterization of sludge generated in the three-step wastewater treatment. Based on the results of investigation, we can assess the potential of GHGs emissions reduction. The antipated results will be valuable references for governmental regulations and policies for promoting GHGs emissions from livestock wastes management.