The　exposure　to　microplastics　(MPs)　and　nanoplastics　(NPs)　has　been　confirmed　to　exhibit　significant　inhibitory　effects　on　anaerobic　granular　sludge　(AGS)　for　wastewater　treatment,　with　effective　mitigation　strategies　being　accordingly　imperative.　Herein,　this　study　innovatively　proposed　a　strategy　for　mitigating　inhibitory　effects　of　MPs/NPs　on　AGS　system　based　on　coconut　shell-derived　hydrochar　through　efficiently　capturing　the　existing　polyvinyl　chloride　microplastics　and　nanoplastics　(PVC-MPs　and　PVC-NPs)　from　AGS.　The　hydrochar　increased　methane　production　of　AGS　from　69.4%　to　76.2%　and　from　65.6%　to　91.4%　of　control　when　the　AGSs　were　exposed　to　PVC-MPs　and　PVC-NPs,　respectively.　More　extracellular　polymeric　substance　(EPS)　was　secreted　with　the　existence　of　hydrochar,　which　enhanced　the　protective　capabilities　AGS　held　to　against　the　negative　effects　from　the　external　toxicity　of　PVC-MPs　and　PVC-NPs,　thus　maintaining　better　AGS　integrity　regarding　granule　size　and　cell　viability　(especially　for　the　PVC-NPs　affected　AGS).　The　hydrochar　showed　stronger　adsorption　capability　to　PVC-MPs　and　PVC-NPs　than　AGS,　confirmed　by　their　characteristics　and　adsorption　kinetic　tests.　As　a　result,　less　plastic　particles　would　attach　AGS,　inducing　less　oxidative　stress　to　the　microbes.　Specially,　it　would　also　be　less　likely　for　PVC-NPs　to　penetrate　through　AGS　surface　and　enter　the　internal　core,　retaining　better　richness　of　bacteria　such　as　Bacteroidales　and　Syntrophobacterales　in　AGS.　This　work　demonstrated　hydrochar　effectively　alleviated　the　suppression　on　AGS　caused　by　PVC-MPs　and　PVC-NPs,　providing　a　novel　strategy　for　improving　the　wastewater　treatment　performance　under　the　stress　of　MPs　and　NPs.　©　2022　Elsevier　B.V.