Engineering　muck　(EM)　in　South　China　is　a　typical　construction　waste,　which　has　a　low　utilization　rate.　After　the　thermal　treatment,　this　study　prepares　the　EM-based　geopolymers　and　evaluates　the　CO2　emission.　The　calcined　EM　and　the　geopolymers　were　characterized　through　thermogravimetric　analysis　(TGA),　X-ray　diffraction　(XRD),　Fourier　transform　infrared　spectroscopy　(FTIR),　scanning　electron　microscopy　(SEM),　mercury　intrusion　porosimetry　(MIP),　and　nuclear　magnetic　resonance　(NMR)　spectroscopy.　The　results　showed　that　when　the　thermal　treatment　temperature　was　850　°C,　the　dissolution　of　aluminum　(Al)　and　silicon　(Si)　was　adequate,　significantly　enhancing　the　reactivity　of　geopolymerization　and　thus　forming　a　geopolymer　with　dense　structures　and　excellent　mechanical　properties.　Notably,　the　compressive　strength　at　7　days　for　the　geopolymer　exceeded　50　MPa,　and　the　cumulative　pore　volume　and　pore　size　distribution　were　both　minimal.　In　addition,　an　environmental　implication　analysis　revealed　that　the　recycled　geopolymers　could　reduce　carbon　emissions　by　approximately　11–65　kg　CO2/t　when　compared　to　conventional　concretes,　contributing　towards　low-carbon　goals.　The　findings　of　this　study　propose　a　more　environmentally　friendly　strategy　for　the　treatment　of　the　EM,　contributing　to　the　advancement　of　sustainable　solid　waste　utilization.　©　2024　Elsevier　B.V.