Insights into the Effects of CeO2 Nanoparticles on Medium-Chain Carboxylates Production from Waste Activated Sludge

The synthesis of medium-chain carboxylates (MCCs) from waste-activated sludge (WAS) upgrading has received considerable attention. However, limited research been conducted on the effects CeO2 nanoparticles (NPs) this process. This study showed that 1 mg/g−TS NPs improved solubilization WAS, resulting in higher production MCCs. At 5 mg/g−TS, weakly inhibited 3 biological steps. Despite this, there was an enhancement WAS solubilization, thus overall MCCs similar to control. doses ranging 25–100 were unable offset inhibition, leading a decrease MCC production. toxic mechanisms involved not generation reactive oxygen species or Ce ions anaerobic sludge, but instead decline extracellular polymeric substance (EPS) and destruction cell membrane through physical penetration. Microbial community analysis confirmed increased relative abundance key bacteria fermentation WAS. microbe Clostridium sensu stricto enriched control group, while genus significantly reduced with 100 NPs.