BIOL241 Final: Unit 8- Wastewater and Sewage Treatment
Document Summary
Wastewater: liquid effluents derived from domestic sewage or industrial sources, which for reasons of public health and for recreational, economic, and aesthetic considerations, cannot be disposed of merely by discarding them untreated into lakes or streams. Also produce wastewater streams need to control may contain toxic substances. Pre-treating liquid waste streams, dump into municipal and treat. **domestic: sewage, grey water (washing, bathing, cooking), food processing. High levels of effluent bas reduce inorganic nutrient levels (n, p) Pathogens, parasites :(salmonella, vibrio, cryptosporidium, viruses, helminth worms) Primary treatment (physical) screening: removal of large objects sedimentation: of grit, solids. Secondary treatments (biological) trickling filter (aerobic), or activated sludge (aerobic) sludge digestion (anaerobic) (b/w s &t) disinfection (chemical) Tertiary treatments (chemical, biological, physical) any physicochemical or biological process employing bioreactors, precipitation, filtration, or chlorination procedures similar to those employed for drinking water treatment. Retrofitting plants so they can do that is very expensive.