Sewage treatment processes
- Screening and grit removal protect downstream treatment
- Primary settling removes settleable solids
- Attached microbial growth treats biodegradable organic matter
- Activated sludge recycles microbial biomass after settling
- Disinfection targets pathogens rather than all dissolved pollutants
- Nitrification differs from removal of nitrogen from effluent
- Removing phosphorus held in treatment biomass
- Onsite and cluster treatment differ from centralised sewerage
- Septic systems require removal and safe management of accumulated solids