长链脂肪酸对厌氧颗粒污泥产甲烷毒性研究

METHANOGENIC ACTIVITY OF ANAEROBIC GRANULAR SLUDGE BY LONG-CHAIN FATTY ACIDS

在间歇培养中研究了不同长链脂肪酸 ( LCFA)对 UASB和 EGSB两种反应器厌氧颗粒污泥的产甲烷毒性。结果表明 ,庚酸、癸酸和油酸对厌氧颗粒污泥产甲烷活性有较强的抑制 ,EGSB反应器厌氧颗粒污泥对 LCFA的抑制表现出比 UASB反应器厌氧颗粒污泥更大的耐受能力。LCFA主要通过在颗粒污泥厌氧微生物的吸附而破坏菌体细胞膜的结构 ,直接杀死厌氧微生物。厌氧颗粒污泥中 ,利用乙酸的甲烷菌和产氢产乙酸菌受到 LCFA的抑制较严重 。

A series of assays were conducted to assess the toxicity of long-chain fatty acids(LCFA) to methanogenic activity of anaerobic granular sludges from UASS and EGSB reactors. The results showed that n-Heptanoic acid, capric acid and oleic acid had strong inhibition on methanogenic activity of sludges. Sludge from EGSB reactor could bear much higher concentration of LCFA than sluge from UASB reactor. The adsorption of LCFA to cell membrane led to the cell lysis of anaerobes. Among anaerobes, acetate-utilizing methanogens and hydrogen-producing acetogenic bacteria suffered much higher inhibition from LCFA than formate-utilizing methanogens and hydrogen-utilizing methanogens.