Feeding controls HS production in situ in high solid anaerobic digestion.

In this study, a high frequency monitoring method was used to assess how semi-continuous feeding affects HS production in high solid anaerobic digestion. The results showed that HS characteristics at a monitoring frequency of 1 point/3 h were different to that of 1 point/24 h, its concentration decreased from 3449 ± 227 mg/m at 0 h to 298 ± 45 mg/m at 3 h. HS concentration was negatively correlated with volatile fatty acids (VFAs), and oxidation reduction potential (ORP). 72-82% of HS reduction in the first 3 h resulted from the introduction of O during feeding, and 18-28% of that was closely related to the production of a large quantity of soluble acidic matter, such as VFAs. A more accurate HS release model was established according to the content of VFAs. Totally, this study implies that feed carrying air is a promising method for in situ control of HS production in anaerobic digestion.