Fecal Coliform The number of Fecal Coliform in an effluent sample is reflected by how many colonies grew on the membrane during incubation and how much sample was filtered through the membrane. After incubation, remove the samples and count all of the blue colonies on each filter. Samples should ideally have at least 1 plate with…
Fecal Coliform Fecal Coliform samples must be collected and transported in specially prepared bottles that have been sterilized and contain a small amount of dechlorinating chemical (Sodium Thiosulfate). If the sample has been disinfected with chlorine and does not get completely dechlorinated, the chlorine will continue to disinfect the sample in the bottle on the…
1. Excessive unbalanced applied voltage causes _. a. the pump to run backwards b. high heat buildup within the stator and rotor assembly c. intense vibration or cavitation 2. Amperage is _. a. a difference of potential or electrical pressure b. a measurement of total energy c. a measurement of electrical flow 3. Which of…
1. The diameter of a wet well is 10 feet. If filled to a depth of 12 feet, it will contain approximately how many gallons of water? 2. How many gallons of liquid can be held by a tank that measures 40 feet long by 25 feet wide by 12 feet deep? 3. Approximately how…
BOD The D.O. measurements conducted as part of the BOD test can be made in two ways; (1) chemically, through the Winkler titration, or (2) electrometrically, with a polarographic D.O. meter. Because of the difficulties involved with the Winkler titration method, almost all laboratories use D.O. meters for performing the BOD test. D.O. meters can…
BOD Because this test relies in part upon living microorganisms, many things can go wrong, with the outcome being inaccurate results. To avoid this, quality controls are used when running the BOD. These are: Dilution water blanks Oxygen Depletion Rules Sample pH adjustments Dechlorination of Chlorinated Samples Dissolved Oxygen Meter…
BOD Test After the 5 days of incubation, the BOD bottles are removed from the incubator and the level of dissolved oxygen is again measured in the bottles. This is known as the Final D.O. The amount of dissolved oxygen that was consumed during the incubation is related to the strength of the sample and…
BIOCHEMICAL OXYGEN DEMAND (BOD5) Being able to measure the “strength” of wastewater is important for controlling treatment systems and for measuring the effectiveness or treatment. The Biochemical Oxygen Demand (BOD) is a test that measures the biological and chemical oxygen demand of wastewater. In the BOD test, wastewater samples are incubated at 20° C for five…
1. Convert 30 HP into kW. If this piece of equipment runs for 80 hours and electricity costs $0.07 per kilowatt hour, what will it cost? 2. Convert 144 square inches into square feet 3. Convert 20 gal/sf to liters per square meter 4. A tank contains 20 feet of water and is 10 feet…
1. Your municipality seeks your advice in preparing a new ordinance pertaining to the use of sewers. What three items are considered the most important and which would have the most impact on the operation of the treatment plant? a. Quantity of flow, strength of wastewater, and toxicity of wastewater b. Strength of wastewater, temperature…
