Wastewater Treatment Fact Check: True or False Questions and Answers, Exams of Water and Wastewater Engineering

Download Wastewater Treatment Fact Check: True or False Questions and Answers and more Exams Water and Wastewater Engineering in PDF only on Docsity! Wastewater Treatment Operator Certification Test 3 Questions With 100% Correct Verified Answers The typical suspended solids removal rate in the primary clarifier is 5 to 10% True or False - False (v.1 pg 129) Over-greasing a pump motor can lead to damage. True or False - True (v.2 pg 404) A healthy digester gas consists mostly of hydrogen sulfide. True or False - False (v.2 pg 158) Coliform results are reported as MPN/100 ml True or False - True (v.2 pg 556) Increased concentrations of volatile acids and decreased alkalinity are signs that the anaerobic digestion is in an ideal state. True or False - False (v.2 pg 523) Breakpoint chlorination is the addition of chlorine to wastewater until the chlorine demand has been met. True or False - True (v.1 pg 351) Zero calibration accuracy for DO probes and meters should be checked with an absolute zero solution (sodium sulfite) True or False - True Temperature, pH, and dissolved oxygen do not have to be analyzed immediately because they can be preserved. True or False - False (v.2 pg 499,502) Sterilization is the goal of most wastewater treatment plants True or False - False (v.1 pg 54) One of the most common types of packaged plants is extended aeration True or False - True (v.1 pg 257) NPDES permits are issued by the EPA or the state True or False - True Hypochlorination will raise the pH of wastewater being treated True or False - True (v.1 pg 351) Denitrification does not cause sludge to rise in a secondary clarifier True or False - False (v.2 pg 73) The sludge digester can be either aerobic or anaerobic True or False - True (v.2 pg 148,217 In order to protect your family from infectious disease, you should not wear your work clothes home. True or False - True (v.2 pg 266) One application of centrifugal pumps is to lift raw wastewater. True or False - True BOD and suspended solids are measured using grab samples True or False - False(v.1 pg 317) Algae uses carbon dioxide in the pond to produce free oxygen for the aerobic bacteria. True or False - True (v.1 pg 299) The purpose of a scraper in a clarifier is to collect the settled wastewater flowing over the weirs and convey it from the clarifier. True or False - False (v.1 pg 115) An oxidation ditch is typically used for small communities. True or False - True (v.1 pg 269) If there is white foam on the surface of the aeration tank, increase the sludge waste rate. The preliminary treatment system mainly removes larger solids, such as rocks, debris, and grit. True or False - True (v.1 pg 41,65) Vacuum filtration is one method to settle solids in a primary treatment. True or False - False (v.2 pg 222,224) Land application is one type of disposal method for sludge. True or False - True (v.1 pg 55) F/M ratio is a control method for the activated sludge process. True or False - True (v.2 pg 58) The drive unit in a circular clarifier rotates the sludge collector. True or False - True (v.1 pg 115) Oxygen deficiency is most likely to occur at the high point within an above ground structure. True or False - False (v.2 pg 270) Chlorine demand concentration is often determined using the DPD test. True or False - False (v.1 pg 359) When algae consumes carbon dioxide from a waste stabilization pond, the pH of the wastewater in the pond will increase. True or False - True (v.1 pg 299) Which of the following is true about bacteria? A) The Most Probable Number method is not applicable for analyzing wastewater for coliform, but it is frequently used to determine the ciliate concentration B) Multiple tube coliform test is not frequently used to determine coliform bacteria due to its complexity C) Coliform bacteria are considered harmless, but their presence may indicate the presence of pathogens. D) Test for coliform bacteria cannot be used by an operator at a treatment plant as a guide to achieve desired degree of treatment. - C) Coliform bacteria are considered harmless, but their presence may indicate the presence of pathogens (v.2 pg 551,553) What is the typical removal efficiency of total suspended solids in the primary clarifier? A) 95 to 99% B) 20 to 50% C) 10 to 15% D) 40 to 60% - D) 40 to 60% (v.1 pg 129) Which of the following is the most abundant in an anaerobic digester? A) Carbon dioxide B) Nitrogen C) Methane D) Hydrogen sulfide - C) Methane (v.2 pg 158) What might cause brown or black scum to appear on the surface of a pond? A) Low BOD loading B) Pond is overloading (BOD) C) Storm D) Periods of high runoff - B) Pond is overloading (BOD) (v.1 pg 308) What is the purpose of air input for an aerated grit chamber? A) Helps remove TDS B) Air improves the disinfection process C) Freshens wastewater and helps separate grit and other solids D) Addresses denitrification - C) Freshens wastewater and helps separate grit and other solids (v.1 pg 42) What happens when there are many air bubbles in the water of an operating pump? A) Water hammer B) Cavitation C) Less noise generated by the pump D) More efficient pumping - B) Cavitation (v.2 pg 346) Which are the common characteristics of COD? A) COD is typically larger than BOD and COD test results are available sooner than BOD B) COD is typically smaller than BOD C) COD is usually equal to BOD D) COD results are available after 4 days of testing - A) COD is typically larger than BOD and COD test results are available sooner than BOD (v.2 pg 541) What happens when free chlorine reacts with ammonia? A) Forms chlorine dioxide B) Forms hydrogen sulfide C) Forms ozone D) Forms chloramine - D) Forms chloramine (v.1 pg 350) What should be done if you see sludge rising in the primary clarifier? A) Reduce frequency of sludge pumping B) Adjust the MCRT C) Remove sludge more frequently D) Fix uneven weir setting - C) Remove sludge more frequently (v.1 pg 130) Which of the following is true about trickling filters? A) Its mostly an anaerobic process B) Its mostly an anoxic process C) Photosynthesis is an important part of the trickling filter D) Its mostly an aerobic process - D) Its mostly an aerobic process (v.1 pg 175) How does temperature affect the activity of microorganisms in a an aeration tank? A) Low microorganism growth rate as temperature increases B) Rapid microorganism growth rate as the temperature increases C) Does not affect activity of microorganisms D) Decrease in temperature will result in more biological activity - B) Rapid microorganism growth rate as the temperature increases (v.2 pg 71) What change would most likely be made to an activated sludge process during the winter? A) Decrease solids under aeration B) Increase pH C) Increase solids under aeration D) Add chlorine to the influent of the aeration tank - C) Increase solids under aeration (v.2 pg 71) If the influent solids loading rate to an activated sludge system increases, what should be done? A) Increase sludge waste rate B) Decrease MLSS C) Decrease temperature of aeration tank D) Reduce wasting rate of the sludge - D) Reduce wasting rate of the sludge (v.2 pg 53) What could happen if a valve is closed to quickly?