1. Collections: force mains, lift stations, and pumps
2. Treatment Facilities: The actual plant where the processing of waste takes place.
3. Discharge or Disposal: the pumps and infrastructure required to dispose of the treated water.

What are the three types of wastewater collection systems?

1. Storm Sewer : Carrying water from storm drains, run offs, roof drains, and drainage systems.
2. Sanitary Sewer : carrying sewage from households, businesses, and  industries.
3. Combines Sewer : Carrying both sanitary sewage and storm water.

1. Organic : waste matter, vegetable scraps, fats oils grease, leaves.
2. Inorganic : sand , grit , plastics.
3. Thermal : cold water from chillers and hot water from boilers drains and steam plants.
4. Radioactive : waste from medical facilities, x ray dyes.

1. Cholera
2. Typhoid
3. Hepatitis
4. Dysentery
5. Cryptosporidium
6. Giardia

The above are examples of :

Trickling filters, RBC's, and Aerated activated sludge are examples of :

Air is supplied to the Mixed liquor in the activated sludge process for Two reasons :

1. To supply oxygen to the microorganisms
2. To bring the microorganisms into contact with the incoming food.

With the exception of the Complete Mix process, all Activated Sludge processes are _Plug_flow designs.

This means the flow runs from one end to the other as in a pipe. Complete mix systems in corporate flow and aeration to cause mixing through turbulance.

1)      Air is supplied in two ways:

a)      Mechanical aeration: using propellers or rotors to agitate the surface of the water to mix the air into the water.

b)      Diffused air: The use of blowers (either centrifugal or positive displacement) to supply the air through a series of air pipes (Headers) and perforated devices called diffusers.

1)      Diffusers can be classified by their bubble size;

a)      Fine bubble diffusers: Plate and tube or dome diffusers.

b)      Medium bubble diffusers: Porous nylon or Dacron socks or saran fiber glass wrapped tubes.

c)      Coarse bubble diffusers: are generally plastic tubes with holes in them or large bore duck bills. 

It takes about 1.5 lbs. of DO to convert 1 lb. of CBOD to CO² and Water.

      It takes approximately 4-5 pounds of D.O. to convert one pound  of ammonia to  nitrate.

1.     MCRT= Mean Cell Residency Time, (SRT Sludge Retention Time), the average time a microorganism will spend in the activated sludge process, controlled by wasting.
2.       F/M Ratio = Food to Microorganism ratio, measure the amount of food (CBOD) compared to the amount of microorganisms there is to consume it.
3.       Sludge age (GSA Gould Sludge Age) = Measure of how old your sludge is. Controlled by wasting.
4.       MLSS target mg/L = Keeping you MLSS mg/L at a specific range through wasting.
5.       Settleometer ml/L= a measure of how well your sludge is settling. Controlled by D.O. and RAS and WAS flow control.

      Of the two, Sludge age and MCRT, MCRT is considered the most accurate.

    Ponds are classified by the type of treatment the water receives coming to the pond.

    Ponds receiving raw waste are called Stabilization ponds.

     Ponds receiving water after primary treatment are called Oxidation ponds.

   Ponds receiving water after secondary treatment are called Tertiary treatment ponds.

The three types of ponds are Aerobic, Anaerobic, and Facultative.

   Aerobic Ponds = Having D.O. distributed throughout the pond.

     Air can be supplied by algae during the day or mechanical aeration.

    Anaerobic = Having no D.O. or oxygen present other than in chemical form, such as NO₂ nitrite or NO₃ nitrate.

      Facultative = Ponds that have a lower anaerobic zone and an upper aerobic zone.

     Disinfection is the process of killing or inactivating most microorganisms in water or wastewater.

1.       Chlorination = the use of chlorine is the most widely used method of disinfection in water and wastewater.
2.       UV ultraviolet light = the use of UV rays to damage the genetic material of microorganisms to make the unable to reproduce.
3.       Ozonation = the use of O³ or Ozone, to disinfect water or wastewater.

1)     Prevent the spread of Pathogenic Microorganisms and disease to:

a)      Public water supplies

b)      Receiving waters used for public recreation.

c)       Water used for shell fisheries.

a)      Gas = 100 percent chlorine , a greenish yellow gas, highly toxic, it comes in 100 or 150 pound cylinders, one ton cylinders, and Rail Tankers to 90 tons.

b)      Calcium Hypochlorite = Granular and tablet form 65 to 75 percent chlorine.

c)      Sodium Hypochlorite = Bleach, industrial strength varies by manufacturer, usually 10-12 percent chlorine.

    It is detectable at .08 ppm in the air.

     It is dangerous for long term exposure a 5 ppm in air.

    It is lethal at 1000 ppm in air.

      When changing a gas cylinder for chlorine it is important to use proper safety equipment and to never work alone.

1)      Repair kits are available for chlorine cylinders:

a)      “A” kit for 100 and 150 pound cylinders

b)      “B” kit for one ton cylinders

c)      “C” kit is for rail cars.

There are two valves on a one ton cylinder, they sholud be aligned perpendicular  to the ground.

↑      top valve

↓ bottom vlave

↔          ground

Chlorine liduid will expand at a rate of 460 to 1.

This means that 1 cc of liquid will expand to 460 cc of gas.

Chlorine cylinders are equipped with fusible plugs to keep the cylinder from rupturing if exposed to  high heat.

At what temperature will the plugs melt?

       All cylinders are equipped with fusible plugs that will melt at 158^oF to 165^oF  to  

   prevent the tank from rupturing.

      To check for chlorine leaks ammonia is used, a small amount of ammonia vapor is squeezed near the valve and fittings, if a white cloud appears then there is a chlorine leak.

     Sludge digestion can take place either anaerobically or aerobically.

Volatile Acid to Alkalinity ratio is the most imprtant tool used as a process control.

The pH is improtant for Methane Fermenter health, but by the time the pH has risen or dropped the process is already in upset.

Methane fermenters require a very specific pH range to operate properly.

That range is ?

    Methane fermenters are very particular about their pH requirements the range they function best at is between       6.8 -7.2.

There are three types of bacteria that require specific temperature ranges to function.

What are they and at what temperature ranges do they function?

1)      These bacteria  also need specific temperature ranges.

a)  Psychrophilic bacteria = like cold temperature to 68^oF

b)  Mesophilic bacteria = like temperatures between 68^oF and 112^oF, But prefer 85^oF to 100^oF, with the best temperature at 95^oF. Most Anaerobic digesters operate in this area.

c) Thermophilic bacteria = like very high temperatures in the 120^oF to 135^oF range.

      The flame on the afterburner should be Blue to indicate good Methane production, Orange flame is indication of excess CO₂.