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Water Treatment & Wastewater Treatment
Suggested Steps in Water Purification
•Water comes from the stream
•Settling pond - Al2(SO4)3 - ALUM - added to pull clay
particles downward
•Filtration - passing it through porous material (sand)
•Adsorption - use of Carbon to remove organic pollutants
•Biological oxidation - use of bacteria & microbes oxygen helps the organisms grow & eliminate colloidal
•Disinfection - addition of Chlorine, Ozone, or UV to
eliminate harmful pathogens
•Voluntary fluoride treatment & storage in water tower for
drinking water
Water Treatment (for drinking)
Family Water Use
Wastewater Treatment Diagram
Steps in Wastewater Treatment
•Wastewater sent to plant through sanitary sewer pipes
•Pre-treatment - bar screen removes debris
•Primary 1: settling tank- (removes grit), 2: clarifier- (lets
sludge settle while oil is removed by use of a skimmer)
•Secondary - 1: aeration tank -(colloids & organics
removed by hungry bacteria -aeration increases bacterial
growth - substance produced called activated sludge), 2:
clarifier- (lets activated sludge settle - some is reused in
aeration tank & the rest goes to anaerobic digester), 3:
disinfection- (by Chlorine, Ozone, or sunlight in Wetland)
•Tertiary - removal of chemicals (P, N, etc) - not required!
•Anaerobic digester - sludge from primary and secondary
treatment breaks down waste further and can then be
disposed in a landfill or treated and used as fertilizer
•Water returned to the stream
Primary Treatment - Clarifier
Primary Treatment (Oil Skimmer)
Secondary Treatment - Biological Oxidation
(Aeration Tank)
Secondary Treatment (Trickling)
After Anaerobic Digestion of Sludge &
Activated Sludge - Uses
Biogas - produced (along with sludge) during
anaerobic digestion - can be used as a source of
fuel for energy
Co-composting -- combined post-consumer waste
paper with treated sludge (then decomposed by
bacteria) for use as fertilizer for animal crops only
Pasteurization - drying sludge in ovens to kill
pathogens (treated), then can be made into pellets
and sold as fertilizer
Restored Orlando Wetlands
Natures Method of Water Treatment
•Settling ponds to collect large particles
•Filtration by percolating water through soil
•Soil and humus absorb organic nutrients
•Biological filters - bacteria, microbes in soil
& water eat dissolved organic material
•Disinfection - sunlight over 1 week’s time
provides the needed UV to kill pathogens
•In other words -- a WETLAND area!
The Value of Wetlands
•Filter Toxic Waste, sediment, nutrients
•Help prevent erosion
•Reduce flooding by storing storm water
•Reduce storm damage- absorb waves
•Feeding, resting spot for migratory birds
•Provides nesting grounds for aquatic species
•Provide food & habitat for aquatic species

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