常规流态下铝污泥灰涂层对污水管道沉积物变化特征研究OA

To address the issues of clogging and corrosion caused by sediments in sewage pipelines and the disposal challenges of aluminum sludge from water treatment plants,this study proposed a"waste control by waste"approach by utilizing thermally activated aluminum sludge ash(ASA)as a functional component.Cement-based coatings were prepared with ASA incorporation rates of 0%,10%,20%,and 30%,and long-term experiments were conducted in a simulated sewage pipeline system to investigate their anti-sedimentation effects and mechanisms.The results indicated that the ASA coating inhibits sediment accumulation through a synergistic physico-chemical-biological mechanism.Physically,with 30%ASA incorporation,the coating surface roughness decreased from 4.1 μm to 2.8 μm,and the contact angle increased from 9.74° to 40.17°,forming a low-roughness,weakly hydrophilic surface that hinders the adhesion of microorganisms and particles.Chemically,the coating enabled sustained slow release of Al3+(following first-order kinetics,R2>0.99),and exhibited excellent corrosion resistance with only 1.7%mass loss after 180 days of acid immersion.Biologically,the 30%ASA coating reduced the proportion of viable cells in the biofilm to 44.9%,decreased the total extracellular polymeric substances(EPS)by 57%(with a 69%reduction in protein content),and suppressed key functional microbial groups such as Bacillota,Chloroflexota,and Trichococcus,thereby weakening biofilm stability.The coating effectively inhibited sediment accumulation,particularly the organic biofilm layer,providing theoretical support and a technical pathway for the resource utilization of aluminum sludge and the long-term control of sediments in sewage pipelines.