Volatile　fatty　acids　(VFAs)　extraction　from　waste　activated　sludge　(WAS)　during　anaerobic　digestion　has　gained　prominence　for　its　economic　advantages　over　biogas　production.　Critical　strategies　include　enhancing　WAS　solubilization　and　selectively　suppressing　methanogens　to　promote　VFA　accumulation.　The　efficacy　of　peracetic　acid　(PAA)　in　dissolving　WAS　has　been　demonstrated.　However,　its　selective　inhibitory　effects　remain　largely　unexplored.　This　work　illustrated　that　PAA-enhanced　anaerobic　digestion　(PAA-AD)　utilising　a　modest　dose　of　PAA　(9　mg　PAA/g　TSS)　within　the　range　of　0–18　mg　PAA/g　TSS　resulted　in　a　330　%　increase　in　VFA　accumulation,　with　VFA　concentration　and　acetate　proportion　attaining　3235.5　±　60.7　mg　COD/L　and　74.6　%,　respectively.　The　generation　of　CH3C(O)OO·,　·OH,　·O2−,　and　1O2　impaired　the　integrity　of　cell　membranes　and　induced　lipid　peroxidation.　9　mg　PAA/g　TSS　treatment　significantly　reduced　microbial　cell　attraction　in　WAS,　overcoming　WAS　dispersion＇s　energy　barrier　via　the　extended　XDLVO　theory.　This　study　showed　that　its　biological　inactivation　effect　on　VFA　consumers　is　much　stronger　than　VFA　producers.　16S　rDNA　and　metagenomic　analyses　demonstrated　that　PAA　treatment　facilitated　the　selective　enrichment　of　hydrolytic　acidogenic　bacteria　(51.2　%),　including　Paraclostridium,　Macelliibacteroides　and　Clostridium_sensu_stricto_13,　while　significantly　upregulating　genes　linked　to　VFA　synthesis　and　downregulating　genes　associated　with　methane　production.　The　modulation　of　Quorum　Sensing　(QS)　and　Two-Component　Systems　(TCS)　gene　clusters　synergistically　improved　the　chemotaxis　of　aerobic　digesting　bacteria,　facilitating　their　adaptation　to　PAA　stress.　This　study　introduces　a　sustainable　and　economical　approach　for　sludge　treatment　and　resource　recovery,　designed　to　meet　the　carbon　neutrality　objectives　of　wastewater　treatment　plants.　©　2025　Elsevier　B.V.