酸素活性汚泥法の微生物群集構造の解析: 標準活性汚泥法と膜分離活性汚泥法との比較

摘要

活性汚泥法の処理トラブルの解決や性能の向上のためには，反応槽内の微生物群集を理解することが必要である.本研究では16SrRNA遺伝子を対象とした末端標識制限酵素断片多型分析を用いて，都市下水を処理する酸素活性汚泥法の細菌群集構造を解析した.その細菌群集は，窒素除去率が低下した期間を含め，年間で大きく遷移した.標準活性汚泥法と膜分離活性汚泥法の細菌群集と比較したところ，酸素活性汚泥法は特徴的な細菌群集を形成することが明らかとなった.pHや汚泥濃度，溶存酸素濃度の影響により，各活性汚泥法は独特の細菌群集を形成していることが示唆された.%Thorough understanding of the microbial community in the activated sludge process is necessary to solve operational problems and to improve process performance. This study investigated the microbial community in a pure oxygen activated sludge process for treating domestic wastewater. The bacterial community structure was characterized using terminal restriction fragment length polymorphism targeting the 16SrRNA gene. The bacterial community in the pure oxygen activated sludge changed dynamically throughout a year, including alow nitrogen-removal period. Comparison with a conventional activated sludge process and a membrane bioreactor showed that the pure oxygen activated sludge formed unique bacterial communities. It was inferred that the bacterial communities in the pure oxygen, the conventional, and the membrane activated sludge processes were influenced by pH， the sludge concentration, and the dissolved oxygen concentration.