ASP-systemer (Activated sludge Process) bruker strøm til å blåse luft ut i rått, urolig kloakk. Dette knuser de faste stoffene for å utvikle en biologisk "suppe". Lufting gjør det mulig for de naturlig forekommende bakteriene i avfallet å fordøye organisk innhold, noe som reduserer det totale forurensningsnivået. ASP-renseanlegg har ikke et primært setningskammer, noe som betyr mindre hyppig tømming og færre uønskede lukter.
Once the sewage has been aerated for long enough, excess liquid is discharged into a clarification chamber, where live bacteria settle to the bottom. Dead bacteria rise to the top, leaving clean water in the middle – which can then be discharged safely into either a watercourse, drainage field or soakaway.
NEDSENKEDE LUFTINGSFILTRE
In a submerged aeration filter, a primary settlement chamber holds solid material. This is where anaerobic digestion by bacteria takes place. Clarified water then passes into a second chamber containing a submerged media – and here, the water is treated to remove dissolved constituents by aerobic bacteria, supported by diffused air. This process ensures that full treatment is achieved before the material flows to a final settlement chamber. The final, treated wastewater is discharged to the drainage field, watercourse or soakaway.