Dr. Martin T. Auer MTU Department of Civil & Environmental Engineering Wastewater Treatment
The Clean Water Act ‘fishable-swimmable’ Total Maximum Daily Loads Technology-Based Standards Water Quality-Based Standards Discharge Permits (NPDES) yes no yes POTW Design
Federal Water Pollution Control Act Amendments of 1972 (The Clean Water Act) Technology-based effluent limits Water quality-based effluent limits Total Maximum Daily Loads (TMDLs) National Pollutant Discharge Elimination System (NPDES) Add Clark In A Watershed – Everyone Lives Downstream
Receiving Water Impacts River DO Model Q = 8 C = 0, 250, 100
Michigan NPDES Permit
Treatment Plant Design Design Model C in = 250 k = 0.1 V = 0, 250, 750
Aluminum Forming Battery Manufacturing; Cement Manufacturing; Coil Coating & Can Making; Copper Forming; Dairy Products Processing; Electrical & Electronic Component Manufacturing; Electroplating & Metal Finishing; Explosives Manufacturing; Fruit & Vegetable Processing; Ferroalloy Manufacturing; Fertilizer Manufacturing; Glass Manufacturing; Gum & Wood Chemicals Manufacturing; Ink Formulating; Inorganic Chemical Manufacturing; Iron & Steel Manufacturing; Leather Tanning & Finishing; Meat Products Processing; Metal Molding & Casting; Mining Operations; Nonferrous Metals Processing; Organic Chemicals, Plastic & Synthetic Fibers Manufacturing; Paving & Roofing Materials Manufacturing; Soap & Detergent Manufacturing; Petroleum Refining; Pesticide Manufacturing; Porcelain Enameling; Pharmaceutical Manufacturing; Plastic Molding & Forming; Pulp, Paper and Paperboard Manufacturing Timber Products Processing; Textile Mills Federally-Regulated Non-Domestic Sources
Chemicals Designated as Priority Pollutants (126) AROCLOR 1254 (industrial product; banned) BENZENE (industrial product) BENZO(A)PYRENE (asphalt roofing manufacture) CADMIUM (heavy metal; electric/gas industries) CHLORDANE (pesticide; banned or restricted) CHROMIUM (heavy metal; widely used in industry) DDT (pesticide; banned or restricted) ENDRIN (pesticide; banned or restricted) MERCURY (heavy metal; electric/gas and chemical industries) PENTACHLOROPHENOL (industrial chemical – wood products) TOLUENE (widely used industrial chemical) TRICHLOROETHYLENE (industrial solvent, degreaser)
What’s in wastewater? Waste human feces and urine food from sinks soaps and other cleaning agents runoff from streets and lawns industrial discharges
What’s in wastewater? Water lots of it! Urinal - 1 gallon per flush Toilet - 4 gallons per flush Shower - 20 gallons per use Overall - 55 gal/person/day
It’s mostly water! There are about 500 parts of waste in every 1 million parts of wastewater; that’s 500 ppm. It’s like trying to find this class at a sold out Packers game! H2OH2O
So what’s the problem? P SNOT: it’s not a pretty picture!
Composition of Domestic Wastewater ConstituentInfluentEffluent Suspended Solids BOD Ammonia Nitrogen Phosphorus Fecal Coliforms All concentrations are mg/L, except fecal coliforms which are colony forming units (cfu) per 100 mL.
Where does it go when you flush the toilet? This is really not something I’ve given a lot of thought to.
Collection Systems
Portage Lake Sewer System Hancock Houghton Franklin Sq. Super 8 MTU M&M Bldg. POTW P P G G G G P Surface; 30” 10’;36” Lake; 48” 20’; 48” Near Surface; 30”
Metcalf & Eddy Diurnal Variation in Wastewater Flow
Metcalf & Eddy Wet-Dry Variation in Wastewater Flow
Preliminary Treatment Overview (plant protection) Bar Rack or Screen or Comminutor Grit Chamber Flow Equalization from pumps or wet well to primary treatment
Preliminary Treatment: Bar Rack
Preliminary Treatment: Screen
Comminutor Preliminary Treatment: C
Preliminary Treatment: Grit Chamber
Preliminary Treatment: Flow Equalization The Henry Fork Wastewater Treatment Facility, Hickory, NC
Bar Rack or Screen or Comminutor Grit Chamber Flow Equalization from pumps or wet well to primary treatment Preliminary Treatment Overview (plant protection)
(Kiely, 1997) Primary Treatment (solids, sedimentation)
Primary Treatment – Design InOut vpvp The critical particle is defined as that particle will be captured prior to exiting the sedimentation tank. This particle, and all particles which settle more rapidly, will be retained. The critical settling velocity, v c, is that of the critical particle.
Primary Treatment – Design The design parameter for primary treatment is the surface overflow rate, which can be shown to be equivalent to the critical settling velocity, InOut
Primary Treatment – Design InOut V c, SOR v p1 The design objective then is to reduce v c (SOR) in order to capture the target particle. v p2 The steeper the slope, the higher the settling velocity
Primary Treatment – Design InOut vcvc v p2 v p1 This is accomplished by manipulating the tank residence time ( ) by changing the surface area (A), The steeper the slope, the higher the settling velocity
(Kiely, 1997) Primary Treatment – Design
Primary Treatment: Rectangular Clarifier
Primary Treatment – Circular Clarifier
Secondary Treatment (biological) Simple carbohydrates (a form of organic matter) are produced by plants through the process of photosynthesis. These are then converted to more complex carbohydrates and other forms of organic matter such as starches, fats and proteins. The sun’s energy, captured during photosynthesis, is stored in the chemical bonds of this organic matter. Organisms (from bacteria to humans) take up and metabolize organic matter to obtain the energy required to support life. In secondary or biological treatment, we utilize microorganisms to remove the dissolved and small particulate organic matter which would exert an oxygen demand if it were released to the environment. The waste (actually organic matter) is simply converted into another form (microorganisms) which can then be separated from the waste stream by settling yielding a clean effluent.
The Microbial Loop in Nature
Microorganisms in Secondary or Biological Treatment Source:
The Microbial Loop in Secondary Treatment
Secondary Treatment: Trickling Filter
Secondary Treatment: Trickling Filter Media Image Source: Wastewater Engineering, Metcalf & Eddy
Secondary Treatment: Rotating Biological Disks
Secondary Treatment – Activated Sludge
The Monod Curve (From Kiely, 1997)
Batch Growth Curve
F/M Ratio versus BOD Removal Efficiency (From Kiely, 1997) Endogenous Growth Log Growth Declining Growth
Activated Sludge: aeration (diffuser)
Activated Sludge: aeration (mechanical)
Activated Sludge: Plug Flow Configurations (From M&E) Plug Flow (Conventional)
Activated Sludge: Plug Flow Configurations (From M&E)
Activated Sludge: Plug Flow Configurations (From M&E)
Activated Sludge: Completely Mixed Flow Configurations (From M&E)
Activated Sludge: Completely Mixed Flow Configurations (From M&E)
Secondary Clarifier
Disinfection (UV light)
putrid: in a state of foul decay, as animal or vegetable matter putrescible: liable to become putrid Putrescible
Anaerobic Digestion: Biochemistry
Anaerobic Digestion: Reactors
Sludge Drying Beds
Belt Filter
Centrifuge
Multiple Hearth Furnace
Land Application The Madison Metropolitan Sewerage District provides wastewater treatment to villages towns and cities surrounding the Madison area lakes. Biosolids produced at the MMSD Nine Springs Wastewater Treatment Plant are recycled to agricultural land as a fertilizer and soil conditioner. Biosolids recycling practices are regulated by both USEPA and Wisconsin DNR to ensure that human and animal health are protected.
Recycling The Milwaukee Metropolitan Sewerage District has been marketing its biosolids as Milorganite, a fertilizer and soil conditioner, for over 80 years. Today, 55,000 tons of Milorganite are sold annually. Milorganite is produced by place dewatered sludge cake in massive dryers with a temperature gradient of °F at the inlet and °F at the outlet. This effectively inactivates viral and bacterial pathogens
Lagoons or Oxidation Ponds
Septic Tanks