Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4996541 | Bioresource Technology | 2017 | 36 Pages |
Abstract
Digesters fed on food waste (high nitrogen content) were operated successfully over an extended period using sidestream biogas stripping to control total ammonia nitrogen (TAN) below inhibitory concentrations. This is the first time biogas stripping has been used to achieve stable thermophilic operation with undiluted substrate of this type. Stripping columns operated batch-wise treated the equivalent of 1.7-4.1% of digester contents daily at pH >10 and 70 °C, with no detrimental effect on digestion. TKN removal was 54%, with potential to recover 3.5 kg N tonneâ1 substrate. When stripping was stopped in one digester TAN increased, accompanied by rising propionic acid concentrations with progressive instability observed from 2.5 g N Lâ1. Eventual failure as TAN approached 5 g N Lâ1 was due to rapid acetic acid accumulation, resulting in a fall in pH to below 6.5. The pattern of VFA accumulation indicated failure of both acetoclastic methanogenesis and acetate oxidation.
Keywords
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
Wei Zhang, Sonia Heaven, Charles J. Banks,