WaterTreatmentWastewaterTreatment Water Treatment & Wastewater Treatment
Suggested StepsinWaterPurification Suggested Steps in Water Purification Water comes from the stream Settling pond - Al 2 (SO 4 ) 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 particles Disinfection - addition of Chlorine, Ozone, or UV to eliminate harmful pathogens Voluntary fluoride treatment & storage in water tower for drinking water
WaterTreatmentfordrinking Water Treatment (for drinking)
StepsinWastewaterTreatment 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
After Anaerobic Digestion of Sludge & Activated Sludge - Uses 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
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!In other words -- a WETLAND area!
TheValueofWetlands 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