Sewage treatment is the process of removing or converting harmful substances in sewage into harmless substances. Below is the three basic methods of sewage treatment:
Physical treatment: Physical treatment mainly removes suspension, solid particles and most suspended solids through physical processes. Common physical treatment methods include:
Sieve and grille: Remove large particles, impurities and waste through sieve and grille.
Settlement: Use gravity to settle the solid particles to the bottom to form a precipitation.
Qi Floating: The floating material and the suspended solid are separated from the water with the lift effect of the bubble.
Filter: Remove small particles and suspension by filtering medium (such as sand, carbon, filter paper, etc.).
Bio -treatment: Biotropic uses the metabolic activities of microorganisms to decompose and transform organic substances in sewage. Common biological treatment methods include:
Aerob point of oxygen: Use oxygen microorganisms to oxidize organic substances into carbon dioxide and water, and produce biological collagen precipitation, such as activated sludge methods and biofilm.
Aerobic treatment: Using anaerobic microorganisms to decompose organic substances under anaerobic conditions to produce gas such as methane, such as anaerobic digestive ponds, anaerobic filters, etc.
Chemical treatment: Chemical treatment can change the composition in the sewage by adding chemical agents or perform chemical reactions to remove specific pollutants. Common chemical treatment methods include:
Setting and flocculation: Add concrete and flocculant to make small particles gather into large clusters, and it is easy to precipitate or filter.
Oxidation and reduction: Use chemical oxidants (such as ozone, hydrogen peroxide) or reducing agents (such as sulfate) to oxidize or restore pollutants to convert it into harmless substances.
Neutral and regulating pH: By adding chemicals such as acid and alkali, regulate the pH of the sewage, neutralize or stabilize the pH value.
These methods are often used in combination to form a composite treatment system to achieve more efficient and thorough sewage treatment effects. Which method or combination is used depends on the nature, capacity and emissions requirements of sewage.