成果報告書詳細
管理番号20100000001988
タイトル*平成21年度中間年報 「微生物群のデザイン化による高効率型環境バイオ処理技術開発/デザイン化微生物群を用いた高効率固定床メタン発酵の研究開発」
公開日2010/11/10
報告書年度2009 - 2009
委託先名財団法人電力中央研究所
プロジェクト番号P07024
部署名バイオテクノロジー・医療技術開発部
和文要約和文要約等以下本編抜粋:1. 研究開発の内容及び成果等 (1)デザイン化微生物群担体へ通電した際の運転結果 デザイン化微生物群担体の電気制御に関して検討するために、通電可能なH型の2槽式の固定床式メタン発酵槽において、炭素板を担体として用いて実験を行った。ドッグフードスラリーを模擬廃棄物として55℃で連続運転し、通電なしの場合(対照区)、設定電位を0.0V、-0.3V、-0.6V、-0.8V(対銀塩化銀電極、以下同様)として通電した場合の計5つの条件で、有機物負荷量を徐々に増大し水理学的滞留時間を短くして72日間運転した。なお、通電なしの場合、電位は-0.47Vであった。設定電位を0.0V、-0.3Vとして通電した場合、電流値は正の値を示し、電極上では酸化反応が起こっており、電極はアノードとして作用した。一方、設定電位を-0.6V、-0.8Vとして通電した場合、電流値は負の値を示しており、電極上では還元反応が起こっており、電極はカソードとして作用した。
英文要約Development of methanogenic packed-bed reactor using designed supporting material with microbial consortium
(FY2007-FY2011) FY2009 Annual Report
Entrusted organization:
Central Research Institute of Electric Power Industry
Collaborative study:
The University of Tokyo
(1) Effects of electrolysis on the performance of methanogenic packed-bed reactors
 The effects of electrolysis on the performance of methanogenic packed-bed reactors were investigated. At an organic loading rate (OLR) of 26.9 g dichromate chemical oxygen demand (CODcr)/L*day, a higher rate of CODcr removal and methane production was seen in the reactors with a potential of -0.6 or -0.8 V, which generated a cathodic electrochemical reaction, than in those with a potential of 0.0 or -0.3 V, which generated an anodic reaction, or in the control reactors without any electrochemical regulation. Electrolysis at a potential of -0.6 or -0.8 V was effective in stabilizing the methanogenic packed-bed reactors with a high OLR.
(2) Quantitative analysis of microbial communities
 The prokaryotes and methanogens present in both the suspended and retained fractions were examined by quantitative real-time polymerase chain reaction analysis. In the retained fraction, higher prokaryotic and methanogenic copy numbers were present in the cathodic reactor (potential, -0.6 or -0.8 V) than in the anodic (potential, 0.0 or -0.3 V) or control reactors. On the other hand, the prokaryotic and methanogenic copy numbers in the suspended fractions were almost similar in all reactors.
(3) Qualitative analysis of microbial communities
 The microbial communities that grew under the various electrolytic conditions of the reactors were compared using terminal restriction fragment length polymorphism analysis. In the suspended and retained fractions of all reactors, the major bacterial terminal restriction fragment (T-RF) was found to be 262 bp in length. At a potential of -0.6 or -0.8 V, minor bacterial T-RFs of 95 and 150 bp were found in the suspended and retained fractions. Similar methanogenic strains were present in all the reactors.
(4) Effects of electrolysis on methanogenic packed-bed reactors
  When electrolysis was carried out at a potential of -0.6 or -0.8 V in the methanogenic packed-bed reactors, a high performance was attained even at a high OLR because the reactor environments were regulated such that they were conducive to the growth of microbial communities.
(5) Effect of ammonium on methanogenic packed-bed reactors
Two kinds of methanogenic packed-bed reactors-with and without supporting material-were compared. In the reactors with supporting material, the rate of methane gas production remained constant up to an ammonium concentration of 3,080 mg-N/L. On the other hand, in the reactors without supporting material, the levels of volatile fatty acids increased and the rate of methane production suddenly decreased when the ammonium concentration was adjusted to 850 mg-N/L. Thus, adding supporting material in the reactors may mitigate the ammonium-mediated inhibition of methane fermentation.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る