内容 |
論文 |
巻 |
25巻2/3号2020年
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Page |
79
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題名 |
高温消化下水汚泥への外部からの水素添加の影響
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Title |
Use of Exogenous Hydrogen for Thermophilic Digestion of Wastewater Sludge |
著者 |
李 忱忱,大下和徹,高岡昌輝,藤森 崇,日下部武敏 |
Authors |
Chenchen Li, Kazuyuki Oshita, Masaki Takaoka, Takashi Fujimori and Taketoshi Kusakabe |
著者表記 |
京都大学大学院工学研究科都市環境工学専攻 |
著者表記(英) |
Dept. of Environ. Eng., Graduate School of Eng., Kyoto University |
著者勤務先名 |
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Office name |
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著者所属名 |
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キーワード |
水素,高温消化汚泥,メタン生成古細菌,酸生成細菌,嫌気性酢酸酸化細菌 |
Key Words |
hydrogen, digested sludge, methanogens, acid formation bacteria, syntrophic acetate-oxidizing bacteria |
概要 |
本研究は,日本における高温消化下水汚泥に対し,外部から水素を添加した場合のバイオガス生成への影響をバッチ実験より調査した。対象汚泥では,主要なメタン生成古細菌は Methanothermobacter であったが,酢酸利用メタン生成菌としての Methanosaeta 属の存在量は,わずか28%であった。H2添加は酢酸生成と嫌気性酢酸酸化の両方を抑制し,その後メタン生成に影響を与えた。外因性水素の消化阻害による主な理由は,pH増加やCO2減少ではなく,H2濃度増加であった。水素分圧が非常に低くなると,消化は徐々に回復したが,回復時間は水素消費時間より非常に長くなった。 |
Abstract |
The feasibility of using hydrogen (H2) to upgrade biogas during the thermophilic digestion of wastewater sludge was investigated in batch experiments. A high H2 consumption rate of 32.95〜34.13 mL/(gVS・h) was obtained at stirring speed 100 rpm. However, the addition of H2 inhibited significantly the digestion process. Changing the setting of rectors from horizontal to vertical is an effective method for decreasing the rate of digestion inhibition from 93.70% to 54.24%. Moreover, the required recovery time for methane (CH4) generation was much long, although digestion process could gradually recover once the hydrogen partial pressure (PH2) become very low. The inhibited digestion from exogenous H2 was mainly attributed to the increased H2 concentration in sludge rather than the increased pH or CO2 depletion. Thus, adding H2 in the headspace of anaerobic digestor is a feasible method for upgrading biogas as well as avoiding the digestion inhibition
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