1. Hazards that may damage a TV camera going through a sewer include _. a. deep water that submerges the camera b. fogging of optical lens c. offset joints d. all the above 2. Centrifugal pump parts include _. a. diaphragm b. piston c. rotor d. volute 3. When packing a centrifugal pump, the packing…
1. Possible techniques for controlling filamentous organisms in an activated sludge process include _. a. dosage of return sludge with oxidants such as hydrogen peroxide or chlorine b. lower D.O. levels in aeration basins so filamentous organisms cannot breath c. lower F/M level to starve filamentous organisms d. reduce nutrients essential for filamentous organisms e….
Decimals Decimal numbers are used when you need more precision than whole numbers provide. Decimals are based on units of ten (tenths) and multiples of tenths. The value of a digit in a decimal depends on the place of the digit. Examples: 1.234567 – the 1 is in the whole number position 1.234567 – the…
BOD Biochemical oxygen demand or BOD is a chemical procedure for determining the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period. It is not a precise quantitative test, although it…
RAS Chlorination When filamentous bulking problems reach the extent that large amounts of solids are washing out of the secondary clarifier, it is time for drastic measures to be taken to regain control of the situation. One way of doing this is through the introduction of a toxic substance, such as chlorine, into the mixed…
A centrifugal pump moves water by the use of centrifugal force. Any time an object moves in a circular motion there is a force exerted against the object in the direction opposite the center of the circle. This would be easier to explain if we use an example consisting of a person with a bucket…
Pumps serve many purposes in wastewater collection systems and treatment plants. They are classified by the character of the material handled; raw wastewater, grit, effluent, activated sludge, raw sludge, or digested sludge. Or, they may relate to the conditions of pumping: high lift, low lift, recirculation, or high capacity. They may be further classified by…
Manhole Distance / Actual vs On Map A new manhole has been installed 500 ft from an existing manhole. On a map the scale is 1 inch equals 50 ft., what is the distance between the manholes on the map? Given the scale 1 inch equals 50 ft, divide the actual distance by the representative…
To prevent sludge bulking from occurring, the following items should be carefully controlled in an activated sludge plant: 1. Maintain the correct F:M ratio. Carefully review plant records to determine what F:M ratio produces the best quality effluent and long term settling stability. Keep track of influent solids loadings and maintain the desired level of…
Although the activated sludge process can produce an amazingly high quality effluent when it is working well, problems can and do arise. The main problems that occur in the activated sludge process include; solids separation problems, foaming problems, shock loads, septicity and die-off of the microorganisms. Probably one of the most vexing problems encountered by…
