@Article{Diniz_etal2025,
author="Diniz, B. C.
and Wilfert, P.
and Sorokin, D. Y.
and Loosdrecht, M. C. M. van",
title="Anaerobic digestion at high-pH and alkalinity for biomethane production: Insights into methane yield, biomethane purity, and process performance",
journal="Bioresource Technology",
year="2025",
volume="429",
pages="132505",
optkeywords="Anaerobic digestion",
optkeywords="High-pH",
optkeywords="High-alkalinity",
optkeywords="Biogas upgrading",
optkeywords="",
optkeywords="Alkaline waste",
abstract="The role of high-pH conditions in anaerobic digestion (AD) has traditionally been confined to it{\textquoteright}s use in pre-treatment processes. However, operating AD at elevated pH and alkalinity offers significant advantages, including in-situ upgrading of biogas to biomethane. This study examines the potential and scalability of AD under these conditions (pH \~{} 9.3; alkalinity~\~{}~0.5~eq/L). The substrate used was the alkaline waste generated from the extraction of extracellular polymeric substances (EPS) from aerobic granular sludge (AGS), and the inoculum used was a haloalkaliphile microbial community from soda lake sediments. To evaluate the system{\textquoteright}s performance, the organic loading rate (OLR) was incrementally increased. The highest methane production obtained was 8.4~{\textpm}~0.1~mL/day/gVSadded at a hydraulic retention time (HRT) of 15~days and an OLR of 1 kgVS/day/m3. At this loading rate, methanogenesis became the rate limiting conversion. The maximum volatile solids conversion was 48.1~{\textpm}~1.1~\%. Throughout the reactor operation, methane purity in the biogas consistently exceeded 90~\% peaking at 96.0~{\textpm}~0.2~\%, showcasing the potential for in-situ biogas purification under these conditions. In addition, no ammonia inhibition was observed, even with free-ammonia (NH3) concentrations reaching up to 14~mM. This study underscores the potential of high-pH anaerobic digestion as a sustainable method for both waste treatment and energy recovery.",
optnote="exported from refbase (http://www.uhydro.de/base/show.php?record=305), last updated on Thu, 28 Aug 2025 13:27:30 +0200",
issn="0960-8524",
opturl="https://www.sciencedirect.com/science/article/pii/S0960852425004717"
}