Rearranging a Formula Sometimes you need to substitute terms in a formula. The formula below is a common formula used to find the area of a circle. Area, sq ft = 3.14 X R X R where R is Radius However, you may be given the diameter rather than the radius. Given the diameter, you…
1. The granular filter media used to filter wastewater can become coated with a biological slime due to the _ in the wastewater. a. alkalinity b. hardness c. pH d. soluble BOD and ammonia 2. One ton chlorine tanks _. a. have fusible plugs located at valves b. must be stored in an upright position…
1. Mark the correct equation for determining the amount of chlorine required for a dosage of 10 mg/L in 500,000 gallons of flow. a. 0.05 X 7.34 X 10 = lb Cl2 b. 0.05 X 8.34 X 10 = lb Cl2 c. 0.5 X 7.34 X 10 = lb Cl2 d. 0.5 X 8.34 X…
ELECTRICITY Very few operators do electrical repairs or trouble shooting because this is a highly specialized field and unqualified operators can seriously injure themselves or damage costly equipment. For these reasons the operator must be familiar with electricity, know the hazards, and recognize his/her own limitations when working with electrical equipment. Most municipalities employ electricians…
Anaerobic Digestion Pipelines and Valves The pipe used in anaerobic digesters must be able to withstand pumping pressures and severe corrosion. Cast iron or steel is typically used. Plug valves are commonly used in sludge and scum lines. Gate valves or butterfly valves are undesirable and rarely used because grease, rags and debris can catch…
Appurtenances Drop manholes should be used when the difference in elevation between the influent and the effluent of the manhole cannot handle the drop into the barrel without creating excessive turbulence which reduces the production of H2S Back flow preventers are used to stop the accidental backflow or reverse flow of wastewater into buildings. They…
Appurtenances Appurtenances are devices that facilitate and control the flow of wastewater and allow access for maintenance activities. They include manholes, building connections, junction chambers or boxes, and terminal cleanouts, among others. Regulations for using appurtenances in sewer systems are well documented in municipal design standards and/or public facility manuals. Manholes for small sewers 24 inches…
How Anaerobic Digestion Works Anaerobic digestion relies upon the actions of two groups of bacteria living together in the same environment. One group consists of SAPROPHYTIC organisms, commonly referred to as the “acid formers”. The second group, which uses the acid produced by the saprophytes, is the “methane fermenters”. The methane fermenters are not as…
COMMON OPERATIONAL PROBLEMS The operator should check all pumps and motors every day to insure proper operation. After spending a certain amount of time with these pumps and motors an operator should be able to tell just by listening to them whether they are working properly. The vast majority of pumping problems are either a…
1. After a collection system problem has been solved, you should _. a. wait until tomorrow to fill out the report forms b. take a break c. go home d. evaluate the effectiveness of the results 2. Why must you always know where a cleaning tool is in a sewer? a. so the tool can…
