Secondary wastewater treatment

{
  "id": "MLC-T-ENV-025039",
  "term": "Secondary wastewater treatment",
  "field": "Environment",
  "term_source": "Secondary Wastewater Treatment",
  "definition": "1. Treatment (following primary wastewater treatment) involving the biological process of reducing suspended, colloidal, and dissolved organic matter in effluent from primary treatment systems and which generally removes 80 to 95 percent of the Biochemical Oxygen Demand (BOD) and suspended matter. Secondary wastewater treatment may be accomplished by biological or chemical-physical methods. Activated sludge and trickling filters are two of the most common means of secondary treatment. It is accomplished by bringing together waste, bacteria, and oxygen in trickling filters or in the activated sludge process. This treatment removes floating and settleable solids and about 90 percent of the oxygen-demanding substances and suspended solids. Disinfection is the final stage of secondary treatment.\n\n2. Treatment processes, typically biological, designed to reduce the concentrations of dissolved and colloidal organic matter in wastewater.\n\n3. Term as defined in 40 CFR part 133.",
  "subject": "Environmental technologies",
  "references": [
    "USGS Water Science Glossary of Terms",
    "40 CFR 63.1595 (CFR 2013)",
    "40 CFR 125.58 (CFR 2013)"
  ],
  "url": "https://mlchart.com/terminology/environment/secondary-wastewater-treatment/"
}