01-08-2012, 04:18 PM
RDL 740Technologies for Improving Waste Water
editTechnologies for Improving Waste Water.pptx (Size: 954.45 KB / Downloads: 33)
Wastewater
Water that has been adversely affected in quality by anthropogenic or natural influence.
Comprises liquid waste discharged by domestic residences, commercial properties, industry, and/or agriculture
Consists of a wide range of potential contaminants and concentrations.
Sources of wastewater
Human waste also known as blackwater, usually from lavatories
Septic tank discharge
Sewage treatment plant discharge
Washing water, also known as grey water or sullage
Rainfall collected on roofs, yards, hard-standings, etc.
Groundwater infiltrated into sewage
Surplus manufactured liquids from domestic sources
Urban rainfall runoff from roads, car parks, roofs, sidewalks, or pavements
Waste Water Constituents
Pathogens such as bacteria, viruses, prions and parasitic worms
Non-pathogenic bacteria
Organic particles such as feces, hairs, food, vomit, paper fibers, plant material, humus
Soluble organic material such as urea, fruit sugars, soluble proteins, drugs, pharmaceuticals
Inorganic particles such as sand, grit, metal particles, ceramics
Soluble inorganic material such as ammonia, road-salt, sea-salt, cyanide, hydrogen sulfide, thiocyanates, thiosulfates
Processes for Secondary Treatment
Activated Sludge Process:
Reactor is an aeration tank containing a suspension of WW and MO (mixed liquor)
Contents of aeration tank are mixed vigorously supplying oxygen to the biological suspension
Aeration devices include submerged diffusers that release compressed air and mechanical surface aerators that introduce air by agitating the liquid surface
Following aeration step, MO are separated by sedimentation