- 學位論文
廚餘廢水與廢棄活性污泥厭氧共消化之研究
A study on the anaerobic co-digestion of kitchen waste water and waste activated sludge
摘要
本研究為了解廚餘廢水與污泥共消化對有機污泥去除效率的影響，分別進行了批次式、單相式與兩相式的厭氧共消化。在批次式的共消化中，控制廚餘廢水TS＝5%，有機污泥TS＝1%的條件下，以廚餘廢水比污泥之比例為8：1，濃度為131,700mg COD/L的TVS去除效率47.7%最高，同時伴隨有39％的COD去除效率與累積產生232.5mL H2/L的氫氣。 在單相式厭氧共消化中，廚餘廢水比污泥為1：1，負荷為5,027 mg COD/L/day的比例其TVS去除率達到53.7%，COD去除率為51.1%，每克COD產甲烷率為1.73mL/g CODadded，高於只有廚餘廢水單獨消化，負荷為7,958mg COD/L/day，TVS去除率47.9%，COD去除率為14.8%，每克COD產甲烷率為0.17mL/g CODadded，或活性污泥單獨消化，負荷為577mg COD/L/day，TVS去除率24.6%，COD去除率為8.5%，每克COD產甲烷率為0.76mL/g CODadded，證實共消化確實優於單一基質。 在兩相式厭氧共消化的酸化槽中，將混合比分為兩個極端討論，在廚餘廢水比例較多6：1、8：1與1：0的群組中，以負荷為63,295mg COD/L/day的6：1其TVS去除率42.2%與COD去除率28.6%最佳。在污泥比例較多的群組中以負荷為9,787mg COD/L/day的1：15其TVS去除率與COD去除率較佳，分別是25.1%與29.9%。在甲烷化槽中，在廚餘廢水比例較多的群組中，以比例為1：0的TVS去除率與COD去除率最佳，分別是42.7%與33.9%。在污泥比例較多的群組中以比例為1：25的比例有較佳的TVS去除率，有38.6%，COD去除率則是比例為1：20的36.9%為最高。此外，縮短甲烷化槽水力停留時間以提升體積負荷，實驗結果以廚餘廢水比污泥之比例為1：20的反應槽中，甲烷化槽水力停留時間15天，有機負荷為12,800mg/L/day其TVS去除率為33.63%，平均產氣率65.28mL/L/day，甲烷濃度10.44%。 比較生活污水廠、啤酒廠與食品廠的污泥與廚餘廢水共消化的結果顯示，酸化槽皆沒有氫氣產生，其TVS去除率由大到小依次是啤酒廠污泥38.3%、生活污水廠污泥26.3%與食品廠污泥14.5%，COD去除率由大到小依次是生活污水廠污泥25.5%、食品廠污泥17.7%與啤酒廠污泥12.5%。其產氣率由大到小依次為食品廠污泥157.64 mL/L/day、生活污水廠污泥115.40 mL/L/day與啤酒廠污泥108.89 mL/L/day，甲烷濃度，由大到小依次為生活污水廠污泥20.54％、食品廠污泥14.18％與啤酒廠污泥8.02％，每克COD產甲烷率最高的是生活污水廠污泥為1.48 mL/g CODadded。而甲烷化槽比較結果顯示TVS去除率由大到小依次是生活污水廠污泥30.6%、食品廠污泥25.2%與啤酒廠污泥22.2%，COD去除率由大到小依次是啤酒廠污泥36.6%、生活污水廠污泥32.6%與食品廠污泥26.8%，產氣率由大到小依次為啤酒廠污泥141.9 mL/L/day、食品廠污泥87.5 mL/L/day與生活污水廠污泥71.5 mL/L/day，甲烷濃度由大到小依次為食品廠污泥18. 6％、啤酒廠污泥12.2％與生活污水廠污泥10.3％，每克COD產甲烷率最高為食品廠污泥1.06 mL/gCODadded，推測實驗之前各廢棄污泥已進行厭氧分解作用。
並列摘要
A study was conducted to investigate the effect of anaerobic co-digestion of kitchen waste water（KWW) and waste activated sludge（WAS）on removal of organic sludge using batch, single-phase, and two-phase co-digestion processes. In batch process, the highest total volatile solids (TVS) reduction of 47.7 % was achieved with COD reduction of 39 % and 232.5 ml/l hydrogen production, under the condition that the KWW-TVS was 5 %, WAS-TVS was 1 %, the KWW/WAS ratio was 8:1 and COD/l loading was 131,700 mg. In single-phase process, a loading of 5,027 mg COD/l/day with KWW/WAS ratio of 1:1 co-digestion test was compared to a KWW digestion with loading of 7,958 mg COD/l/day, as well as a WAS digestion with loading of 577 mg COD/l/day. It was found that more effective result was reached in co-digestion test with a TVS reduction of 53.7 %, COD reduction of 51.1 % and gas yield of 1.73 ml/g CODadded, compared to the KWW digestion with a TVS reduction of 47.9 %, COD reduction of 14.8 % and gas yield of 0.17 ml/g CODadded, as well as the WAS digestion with a TVS reduction of 24.6 %, COD reduction of 8.5 % and gas yield of 0.76 ml/g CODadded. The result indicated that co-digestion of KWW with WAS is more effective than digestion of KWW or digestion of WAS individually. In two-phase process using acid tank digester, it was examined under high KWW group and high WAS group respectively. For the tested KWW/WAS ratios of 6:1, 8:1, and 1:0, an effective TVS reduction of 42.2 % and COD reduction of 28.6 % was achieved on high KWW group, with KWW/WAS ratio of 6:1 and a loading of 63,295 mg COD/l/day. An effective TVS reduction of 25.1 % and COD reduction of 29.9 % was achieved under high WAS group, with KWW/WAS ratio of 1:15 and a loading of 9,787 mg COD/l/day. While in two-phase process using methane tank digester, an effective TVS reduction of 42.7 % and COD reduction of 33.9 % was achieved on high KWW group at KWW/WAS ratio of 1:0. An effective TVS reduction of 38.6 % and COD reduction of 36.9 % was achieved under high WAS group at KWW/WAS ratio of 1:20. In addition, methane tank digester was operated at shorter hydraulic retention time (HRT) to improve volume loading. The result showed that the TVS reduction was 33.63 %, with average gas production of 65.28 ml/l/day, and methane concentration of 10.44 %, based on the operating conditions of KWW/WAS ratio of 1:20, retention time of 15 days, and organic loading of 12,800 mg COD/l/day, The co-digestion of WAS with different sludges including sewage plant sludge, beer plant sludge, and food plant sludge, was also examined. The results indicated that no hydrogen was produced for using acid tank digester. TVS reduction showed a high of 38.3 % for beer plant sludge, medium of 26.3 % for sewage plant sludge, and low of 14.5 % for food plant sludge. COD reduction showed a high of 25.5 % for sewage plant sludge, medium of 17.7 % for food plant sludge, and low of 12.5 % for beer plant sludge. Gas production rate showed a high of 157.64 ml/l/day for food plant sludge, medium of 115.4 ml/l/day for sewage plant sludge, and low of 108.89 ml/l/day for beer plant sludge. Methane concentration showed a high of 20.54 % for sewage plant sludge, medium of 14.18 % for food plant sludge, and low of 8.02 % for beer plant sludge. The highest gas yields of 1.48 ml/g CODadded was found in sewage plant sludge. For methane tank digester, TVS reduction showed a high of 30.6 % for sewage plant sludge, medium of 25.2 % for food plant sludge, and low of 22.2 % for beer plant sludge. COD reduction showed a high of 36.6 % for beer plant sludge, medium of 32.6 % for sewage plant sludge, and low of 26.8 % for food plant sludge. Gas production rate showed a high of 141.9 ml/l/day for beer plant sludge, medium of 87.5 ml/l/day for food plant sludge, and low of 71.5 ml/l/day for sewage plant sludge. Methane concentration showed a high of 18.6 % for food plant sludge, medium of 12.2 % for beer plant sludge, and low of 10.3 % for sewage plant sludge. The highest gas yields of 1.06 ml/g CODadded was found in food plant sludge.