Primary, secondary, and tertiary treatments are all part of the wastewater treatment process.
• The primary treatment prepares the wastewater for treatment. This involves removing the solid material by allowing the particles to settle in settling basins and by various screening techniques.
• The secondary treatment is the removal of the biological organic material. This involves utilizing trickling filters, lagoons, aeration systems, and anaerobic digesters.
• The tertiary treatment is the removal of inorganic nutrients either through biological or chemical means. There is also virus removal and inactivation, as well as trace chemical removal.