Determination of operating conditions in an anaerobic acid-phase reactor treating dairy wastewater

摘要

Anaerobic digestion of organic material is multistep process. Two groups of bacteria, namely acidogenic and methanogenic bacteria, are responsible for the acidification and the methane formation, respectively. The growth requirements of the two groups of bacteria are rather different. In order to create optimum conditions for the process, it was first proposed to separate the process into two phases~1. Operating variables applicable for the selection and enrichment of microbial populations in phased digesters include digester loading hydraulic retention time (HRT), pH, temperature, reactor design, and operating mode. By proper manipulation of these operating parameters it is possible to prevent any significant growth of methane bacteria and at the same time achieve the required level of acidification of the first reactor. Further enrichment of two cultures is possible by biomass recycle around each phase.