Ca Grade 2 Wastewater Treatment Operator Practice Exam 4 Already Passed

Ca Grade 2 Wastewater Treatment Operator Practice Exam 4 Already Passed 1 mg/l is the same as 1 part per billion ✔✔F A scada system is capable of monitoring and controlling equipment from where? ✔✔remote location A ...

Ca Grade 2 Wastewater Treatment Operator Practice Exam 4 Already Passed 1 mg/l is the same as 1 part per billion ✔✔F A scada system is capable of monitoring and controlling equipment from where? ✔✔remote location A Discharge Monitoring Report is typically submitted to the regulatory agency on daily basis ✔✔False = Monthly A mechanical seal is used to prevent leaks between where? ✔✔between the pump casing and shaft Alkalinity is the capacity of a liquid to neutralize base ✔✔False = Alkalinity neutralizes acids Typical mixed liquor suspended solids concentration is? ✔✔1,000 to 4,500 mg/l Turbidity is caused by... ✔✔suspended matters Algae is not essential to the successful operation of both aerobic and facultative ponds ✔✔False = Algae supply most of the oxygen to the supernattant The addition of acid and CO2 will do what to wastewater? ✔✔lower the pH of wastewater Hydrogen sulfide will deteriorate what kind of structures? ✔✔concrete structures The higher the pH, the better the disinfection ✔✔False = Maintain a dissolved oxygen concentration of 12 to 14 mg/l in the aeration tank ✔✔F What happens when the velocity of the wastewater in a clarifier is greater in some sections than others? ✔✔short circuiting The F/M ratio will decrease when the microorganism population____________in the aeration tank? ✔✔increases Algae growth will be faster when there is less sunlight ✔✔F How do higher temps affection disinfectione rates? ✔✔Disinfection increases at higher temps One of the benefits of recirculation for a trickling filter is that it drcreses the contact time of the wastewater with the biological film ✔✔F How do you prevent foaming from recurring in a anaerobic digester? ✔✔Maintaining a constant temperature Preventative maintenence is a proactive, programmed, and...... ✔✔systematic approach to maintenance Abnormal operation in a pond will not occur if it is overloaded with BOD ✔✔F Anaerobic decomposition of sweage will release? ✔✔hydrogen sulfide Always pour water into acid, and never the other way around ✔✔F Scum escaping in the clarifier effluent could be caused by what? ✔✔hydraulic overload Operate an activated sludge system at low MCRT if you have what? ✔✔limited aeration capacity Chlorine gas is brown in color ✔✔False = yellow green Typical suspended solids concentration of domestic influent wastewater is? ✔✔150 to 400 mg/l Poor ventilation of a trickling filter could lead to what? ✔✔lead to odor problems Sulfur dioxide is used to dechlorinate the effluent prior to discharge to protect what? ✔✔aquatic organisms in the recieving waters MRCT describes the average residence time of the activated sludge particle in the return sludge pipe ✔✔F Free chlorine combines with water to form? ✔✔hypochlorous and hydrochloric acids The trickling filter can be controlled by changing the loadings based on sludge age F/M ratio or MCRT ✔✔F The MPN test for coliform does not test for individual pathegenic microotganism but uses coliform as an indicator organism to estimate the microorganisin population ✔✔T Mixed liquor volatile suspended solids MLVSS is used to determine what? ✔✔the amount of microorganisms in the aeration tank to treat the incoming waste A manhole, sump, or vault can be entered without following confined space entry procedures...... ✔✔if it appears safe An increase in the volatile acids/alkalinity ratio in an anaerobic digester indicates what? ✔✔a problem is developing Chain driven scrapers called flights are commonly used as what? ✔✔mechanical grit collectors A facultative bacteria is capable of living under an aerobic condition but not in an anaerobic condition ✔✔F An impeller is an important part of centrifugal pump that? ✔✔spins the liquid at the high speed Hot bearings in a blower could be caused by what? ✔✔defective bearings Class A fire extinguisher should be used for an electrical fire ✔✔F Scum from primary clarifiers consists mainly of what? ✔✔grease and other floatable materials One of the ways to resolve an increase in the volatile acid/alkalinity ratio in an anaerobic digester is to..... ✔✔decrease raw sludge feed rates Sludge will not become septic when it remains in a channel or basin for an extended period of time ✔✔F Shallow ponds that are used to treat wastewater are typically how deep? ✔✔3 to 5 feet deep A slight seal leakage should be observed when a pump is operating for what purpose? ✔✔to keep the packing cool Total solids = Volatile solids + suspended solids ✔✔F The purpose of sludge wasting in an activated sludge process is to control the amount of solids in the primary treatment process ✔✔F Chlorine gas is not flammable ✔✔T Screening is a part of the pretreatment process that removes what? ✔✔larger debris, such as rocks, cans and bottles The best velocity through a grit channel is 3 foot per second ✔✔F What is the main purpose of the activated sludge process? ✔✔removal of soluble or finely divided suspended materials that were not removed by previous treament Where is the primary sludge typically pumped to? ✔✔sludge digester What problem is caused by denitrification? ✔✔rising sludge in secondary clarifier What condition is necessary to perform a BOD test? ✔✔5 days at 20 degrees Celsius What is a fusible plug? ✔✔a safety device used to prevent build up of excessive pressure in a chlorine cylinder What is usually the last indicator to change in an anaerobic digester that is becoming sour? ✔✔pH What information is needed to calculate the F/M ratio? ✔✔BOD and MLVSS Which chemical is commonly used to control hydrogen sulfide gas? ✔✔Chlorine What would cause a trickling filter to operate less effectively ✔✔Ponding What is MPN? ✔✔Most Probable Number of coliform group organisms per unit volume of sample water What is true regarding dissolved solids? ✔✔they will pass through a filter Why is chlorine sometimes added at the headworks of the plant? ✔✔control order What is the purpose of a launder in a primary clarifier? ✔✔collects the primary effluent that flows over the weir and conveys it towards the next treatment process What is the best way to communicate important information to employees? ✔✔meeting in person What problem might arise from tightening a gland in a pump? ✔✔wear on the shaft or shaft sleeve What could the oxygen uptake rate test be used for? ✔✔detect toxicity in the activated sludge process What does anaerobic bacteria require for metabolism? ✔✔they obtain oxygen by breaking down chemical compounds that contain oxygen, such as sulfite Which of the following is used to dewater sludge? ✔✔drying bed, centrifuge, vacuum filter Which of the following is true about algae in a pond? ✔✔during the day, it consumes CO2 and releases oxygen for the aerobic bacteria in the pond. What is the typical BOD in the secondary effluent? ✔✔between 5 to 30 mg/l What should be done to a chlorine container if liquid chlorine is leaking? ✔✔turn it over so that the leaking side is on top In domestic wastewater system, how many pounds of oxygen are used each day by the microorganisms for each person using the system? ✔✔.17 lbs/day/person (roughly equal to .2 lb/day/person) What terminology indicates the time required to fill a basin at a given flow rate? ✔✔detention time What could happen if the intake of a progressing cavity pump is not kept wet? ✔✔damage pump How should you operate an anaerobic digester? ✔✔the rate of acid formation and methane formation are approximately equal What is the purpose of a check valve? ✔✔prevent liquid from flowing in the reverse direction Which of the following is the best way to detect oxygen deficiency in a confined space? ✔✔reliable and calibrated gas monitor What should be done if filamentous organisms become a problem in the mixed liquor? ✔✔increase DO in aeration tank What is the solids content of a good thick primary sludge? ✔✔4 to 8% dry solids What must be done if you get chlorine in your eyes? ✔✔chlorine must be flushed immediately with large amounts of lukewarm water