Water and Wastewater Treatment Processes Crystal Penton, E.I. Will Larsen, E.I.

Key Concepts Water Cycle Water Cycle Neuse River Basin Neuse River Basin Water Treatment Process Water Treatment Process Wastewater Treatment Process Wastewater Treatment Process

Key Terms Coagulation Coagulation Flocculation Flocculation Sedimentation Sedimentation Filtration Filtration Disinfection Disinfection Activated Sludge Activated Sludge Activated Sludge Process Activated Sludge Process Digestion Digestion

The Water Cycle

NC Watershed Basins

The Neuse River Basin 3 rd largest river basin in North Carolina 3 rd largest river basin in North Carolina Roughly 1/6 of North Carolina’s population lives within the Neuse River Basin Roughly 1/6 of North Carolina’s population lives within the Neuse River Basin –Approximately 1,596,364 People Covers 18 Counties and 77 towns & cities Covers 18 Counties and 77 towns & cities One of only 4 river basin that is completely contained within North Carolina One of only 4 river basin that is completely contained within North Carolina

The Neuse River Basin Neuse River – 248 miles long from the Falls Lake Reservoir Dam to the Pamlico Sound Neuse River – 248 miles long from the Falls Lake Reservoir Dam to the Pamlico Sound At its mouth it’s the widest river in America – 6 miles across At its mouth it’s the widest river in America – 6 miles across Home to several rare or endangered species Home to several rare or endangered species Water quality is effected by sediment, nutrients, toxins, and coliform bacteria Water quality is effected by sediment, nutrients, toxins, and coliform bacteria Dwarf Wedgemussel Alasmidonta heterodon Neuse River Waterdog Necturus lewisi Carolina Madtom Noturus furiosus Roanoke Bass Ambloplites cavifrons

The Neuse River Basin

Water Treatment Process

Raw Water Intake and Screens Intake structure - delivers water to the water treatment plant Intake structure - delivers water to the water treatment plant –Lake or Reservoir –Stream or River –Groundwater Screens – prevent trash, logs, or fish from entering the treatment plant Screens – prevent trash, logs, or fish from entering the treatment plant

Coagulation and Flocculation Coagulation – clumping together of fine particles into larger particles (flocs) caused by the use of chemicals (coagulant) Coagulation – clumping together of fine particles into larger particles (flocs) caused by the use of chemicals (coagulant) Flocculation – the gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing Flocculation – the gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing

Coagulation and Flocculation

Sedimentation Removes suspended solids that are denser than water Removes suspended solids that are denser than water Factors that effect sedimentation: Factors that effect sedimentation: –Particle size –Particle shape –Density of particles –Temperature of the water

Sedimentation Basin

Filtration Filters out the remaining suspended solids Filters out the remaining suspended solids

Sand Filter

Disinfection Disinfection – process designed to kill or deactivate most microorganisms in water, including disease causing bacteria Disinfection – process designed to kill or deactivate most microorganisms in water, including disease causing bacteria Types of disinfection: Types of disinfection: –Physical Ultraviolet (UV) rays Ultraviolet (UV) rays Heat Heat –Chemical Chlorine Chlorine Ozone Ozone Giardia lamblia Fecal Coliforms

Storage and Distribution Storage – keeping water for later use Storage – keeping water for later use –Elevated tanks –Ground storage tanks Distribution system – network of pipes and pump stations that transports finished water from the treatment plant to the user Distribution system – network of pipes and pump stations that transports finished water from the treatment plant to the user

Smithfield Water Treatment Facility

Wastewater Treatment Process

Screens and Grit Removal Screens - used to remove large suspended or floating object in the wastewater Screens - used to remove large suspended or floating object in the wastewater Grit Chamber – chamber where the wastewater’s velocity is reduced to allow heavier grit to settle out and be removed Grit Chamber – chamber where the wastewater’s velocity is reduced to allow heavier grit to settle out and be removed

Screens and Grit Removal

Primary Clarifier Primary Clarifier – causes the velocity of the wastewater to slow, allowing denser sludge to settle to the bottom Primary Clarifier – causes the velocity of the wastewater to slow, allowing denser sludge to settle to the bottom

Oxidation Ditches & Activated Sludge Activated Sludge Activated Sludge –Produced in wastewater by the growth of organisms –Contains many living organisms that feed on the wastewater –Organisms grow in the presence of dissolved oxygen Free Swimming Ciliate Stalked Ciliate Nematode Rotifer

Oxidation Ditches & Activated Sludge Activated Sludge Process – uses the microorganisms in the activated sludge to speed up the decomposition of wastes. As the organisms grow more waste is removed leaving the water partially cleaned. Activated Sludge Process – uses the microorganisms in the activated sludge to speed up the decomposition of wastes. As the organisms grow more waste is removed leaving the water partially cleaned.

Oxidation Ditches & Activated Sludge

Secondary Clarifier Secondary Clarifier - causes the velocity of the wastewater to slow, allowing sludge to settle to the bottom Secondary Clarifier - causes the velocity of the wastewater to slow, allowing sludge to settle to the bottom

Disinfection Disinfection – process designed to kill or deactivate most microorganisms in wastewater, including disease causing bacteria Disinfection – process designed to kill or deactivate most microorganisms in wastewater, including disease causing bacteria Chlorine Contact Chamber Ultraviolet Disinfection

Digester Digestion – sludge is aerated for an extended period of time. As the supply of food is depleted the microorganisms begin to consume one another. The result is inert components and organic compounds that are not biodegradable. Digestion – sludge is aerated for an extended period of time. As the supply of food is depleted the microorganisms begin to consume one another. The result is inert components and organic compounds that are not biodegradable.

Digester

Outfall Outfall – wastewater effluent is discharged into the receiving water Outfall – wastewater effluent is discharged into the receiving water

Benson Wastewater Treatment Plant