发酵种泥的投加对新鲜剩余污泥发酵产酸的影响

Effect of fermented sludge on short-chain fatty acids(SCFAs)production from excess sludge

为进一步提高剩余污泥厌氧发酵产短链脂肪酸(SCFAs)的效率,将p H=10下长期(90 d)厌氧发酵的种泥接入至新鲜剩余污泥考察其对新鲜剩余污泥厌氧发酵产酸的影响.实验在2种p H条件下进行:不控制p H(p H=7.4±0.2),一组反应器中投加新鲜剩余污泥,并接种厌氧发酵种泥,另一组反应器只投加新鲜剩余污泥;控制p H为碱性(p H=10±0.2),一组反应器中投加新鲜剩余污泥,并接种厌氧发酵种泥,另一组反应器只投加新鲜剩余污泥.结果表明:相同p H条件下,接种厌氧发酵种泥反应器中的最大产酸量较不接种分别提高4.9(p H=7.4±0.2)和16.4 mg/g VSS(以COD计)(p H=10±0.2);同时接种发酵污泥、剩余污泥在p H=10±0.2下的最大产酸量较p H=7.4±0.2下的最大产酸量高146.2 mg/g VSS;碱性条件、不接种发酵种泥的产酸量较不控制p H、接种发酵种泥的高129.8 mg/g VSS.投加发酵种泥可提高新鲜剩余污泥厌氧发酵过程中SCFAs的产生效率;碱性条件与厌氧发酵种泥对新鲜剩余污泥发酵产酸具有协同促进作用;与接种发酵种泥相比,碱性条件对新鲜剩余污泥厌氧发酵产酸促进能力高.

To enhance the production efficiency of short chain fatty acids （ SCFAs ） in anaerobic sludge fermentation reactor, sludge from another stabilized fermentation reactor （ over 90 days） under pH 10 was seeded into the reactors to examine its effect on SCFAs production. Two sets of experiment were designed to investigate the SCFAs production with/without seeding sludge under pH=7. 4 ± 0. 2 and pH=10 ± 0. 2, respectively. Experimental results showed that （1） under same pH condition, the maximum SCFAs accumulation with seeding sludge additive increased by 4.9 mg COD/g VSS （pH=7.4±0.2） and 16.4 mg COD/g VSS （pH=10±0.2） respectively, in comparison with the control reactors;（2） with two reactors with seeding sludge, the maximum SCFAs accumulation at pH 10 ± 0. 2 increased by 146. 2 mg COD/g VSS as compared with the condition of pH=7. 4 ± 0. 2; （ 3 ） the maximum SCFAs accumulation at pH 10±0.2 without seeding sludge was 129.8 mg COD/g VSS higher than that of pH 7. 4 ± 0. 2 with seeding sludge. Overall, seeding sludge improved SCFAs production efficiency, meanwhile, seeding sludge under alkaline pH could play synergetic role in enhancing the SCFAs accumulation.