Texas Wastewater Class A (Test 3) Exam Questions and Answers, Exams of Water and Wastewater Engineering

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Texas Wastewater Class A (Test 3) Exam Questions and Answers.

What removes Total Suspended Solids from a sample (TSS) - Correct Answer filtration What chapter of the Texas Water Code gives T C E Q authority to control discharges in Texas. - Correct Answer Chapter 26 Inorganic solids include - Correct Answer sand, grit and minerals Organic solids include - Correct Answer organic materials from plants, animals or humans A good plant influent pH is about - Correct Answer 7. A simple method for indicating when to waste sludge is - Correct Answer 30 minute settling test What is the expected organic loading of a stabilization pond and what is the detention time in days? - Correct Answer 35 pounds, of B O D, per acre, per day, and a detention time of 30 Days Calcium Hypochlorite or HTH, is a - Correct Answer strong Oxidizer and reacts violently with oil and hydro carbons. When added to water what does chlorine form - Correct Answer it forms Hypochlorite, and Hydrochloric acid When ammonia is present in wastewater and reacts with chlorine what is formed - Correct Answer When ammonia is present in wastewater, and reacts with chlorine, Chloramines are formed. Besides disinfection, chlorine has other uses at the wastewater treatment plant such as - Correct Answer Reduces BOD, Odor, Algae growth, Helps with Grease TCEQ allows the reuse of wastewater, some of these include - Correct Answer Irrigation, aquifer recharge, cooling towers and fire protection All reclaimed water piping must be the color - Correct Answer purple When a municipal wastewater effluent has a high nitrate level, and low ammonia level, this most likely means - Correct Answer a high degree of aerobic treatment Total solids in wastewater are the sum of - Correct Answer Settleable and volatile solids

This treatment device is commonly used to separate, and remove large solids from raw wastewater - Correct Answer A Mechanically raked bar screen This test would give the best information on how efficiently a trickling filter was operating - Correct Answer Percent BOD Removal This trickling filter problem could be reduced by increasing the re-circulation ratio - Correct Answer Filter files The minimum size for a gravity flow sewer line on city right-of-way and the minimum grade is - Correct Answer 6 inch and a grade of. percent The most accurate way to find the average wastewater flow rate in an existing 10 - inch sewer main is - Correct Answer Obtaining actual flow data & verifying with field data What is the greatest advantage for using fiberglass manholes in areas with high groundwater? - Correct Answer fiberglass is not subject to infiltration Excessive power consumption by a pump could be caused by - Correct Answer Worn bearings and worn impeller In an excavation, if a ladder is used as a means of exit, it must extend how far above ground, and how far apart laterally - Correct Answer 3 feet / 25 feet laterally the best to determine if a storm drain is connected to a sanitary sewer line is a - Correct Answer Smoke Test What is commonly used to seal joint leaks, on a main with minimal interruption - Correct Answer internal grouting Pre-treatment of wastewater would include: - Correct Answer Coarse or fine screening, grinding and grit removal and grease removal and pre-aeration Primary treatment of wastewater would include - Correct Answer settling tanks or basins, scum collection and removal, sludge collection and removal Solids in wastewater are classified as - Correct Answer Total: solids or residual (TR), Suspended (TSS), Dissolved (TDS), Settleable (SS),

Stabilization Ponds is typically - Correct Answer 35 pounds of b. o .d. with a minimum, of 30 days detention time Wastewater Stabilization Ponds work through a complex process which includes - Correct Answer Sunlight, Oxygen, Nutrients, Algae, and Bacteria Facultative Lagoons have two zones of treatment - Correct Answer an aerobic surface layer and an anaerobic bottom layer In a Facultative Lagoon, typically one could expect - Correct Answer 50% B O D removal, The most common method of dewatering and drying sludge is - Correct Answer drying bed The depth of sludge drawn to a drying bed should be - Correct Answer Approximately 9 to 12 inches When using Hydraulic Hydro Jetting sewer cleaning equipment, the operator will want to go from a clear manhole, and - Correct Answer clean toward the stoppage, to avoid forcing sewage into customer homes, or businesses. The Activated Sludge plant has five (5) Critical Components. They are - Correct Answer Oxygen supply, Aeration tanks, Clarifiers, Return & Waste The Activated Sludge Process can produce a high degree of treatment. Typically one could expect a - Correct Answer 90 to 99%, B O D removal In the active sludge process, Utilization is the process where - Correct Answer Food supply is changed into a liquid state for use In the activated sludge process, Stabilization is - Correct Answer Wastes biologically converted to water, carbon dioxide, or new cells What is the heart In the activated sludge process - Correct Answer Clarifier In the activated sludge process, factors that will influence the operation of the final clarifier are - Correct Answer Loading, solids applied, settling, thickness of solids, rate of return & Wasting In the activated sludge process, the clarifier will concentrate return sludge - Correct Answer two (2) to four (4) In the activated sludge process, as more mixed liquor flows to the classifier, the thickness of the sludge blanket will - Correct Answer Increase as solids accumulate

In the activated sludge process, biological solids from the bottom of the clarifier must be returned to the aeration basin for re-seed. This process is accomplished by - Correct Answer Air lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow In the activated sludge process, no sludge process will work properly without - Correct Answer Regular removal of excess solids In the activated sludge process, Mass Balance refers to - Correct Answer Maintaining the balance between Return Sludge Flow, Return Sludge, Aeration tank volume, Mixed liquor suspended solids In the activated sludge process, the terms F/M ratio is important because this refers to - Correct Answer Food to Microorganism Ratio In the activated sludge process, the F/M Ratio is calculated by ______ the pounds of _________ by the pounds of MLVSS in the ___________. - Correct Answer Dividing/ Incoming BOD/ aeration tank In the activated sludge process, the term Gould Sludge Age refers to - Correct Answer How long in days a pound of solids stays in the aerator In the activated sludge process, Gould Sludge Age (GSA) is calculated by - Correct Answer Dividing the total pounds of TSS in the aerator by the pounds of TSS entering the aerator as raw In the activated sludge process, the term Mean Cell Residence Time (MCRT) refers to - Correct Answer The amount of time the living cells are kept in the plant In the activated sludge process, daily observation of the aeration basin treatment processes are essential. The operator should pay close attention to - Correct Answer Surface turbulence, Foam, Odors, & Color In the activated sludge process, daily observation of the final clarifier is also essential. The operator should pay close attention to - Correct Answer Surface scum, Sludge blanket, Weir Flow, Rising solids, & Clarifier overflow In the activated sludge process, five (5) Important control parameters are - Correct Answer Dissolved Oxygen level, Aerator solids level, Solids quality, Rate of returned sludge, & Wasting rate In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and "Sludge Rising" is typically associated - Correct Answer Nitrification - De-nitrification process

In the activated sludge system if the operator observed uneven surface aeration, dead spots or inadequate mixing in some areas, the operator would suspect - Correct Answer Plugged diffusers In the activated sludge system, if the operator observes white thick billowing sudsy foam on the aeration tank, the operator would suspect - Correct Answer Overloaded aeration tank and or excessive sludge wasting In the activated sludge system, if the operator observes excessive air being used with no apparent change in organic or hydraulic loading, the operator would suspect - Correct Answer Leaks in the system piping, Plugged air diffusers & High organic loading The maximum safe withdrawal rate for a 150 lb chlorine cylinder is - Correct Answer 40 lbs To determine the approximate number of gallons per day being discharged to the collection system, multiply the population by ____ gallons/person/day. - Correct Answer 100 White foam on start-up of AB's is caused by - Correct Answer Low MLSS Total Dynamic Head = - Correct Answer Static Head + Friction Loss CO2 does NOT irritate the ____ _____. - Correct Answer mucous membranes Activated Carbon Beds remove what? - Correct Answer dissolved organics Extended aeration is a _____ process that requires little operator interaction. - Correct Answer simple Activated Sludge - Extended Aeration has 3 major phases: - Correct Answer logarithmic growth phase, declining growth phase, and the endogenous phase Allowable leakage in a new collection system can be tested by ___, ___, and ___. - Correct Answer low pressure air, exfiltration test, infiltration test. When Potable water is used for a hydraulic seal on a pump it should have - Correct Answer an air gap. In a trickling filter, solids removal is affected by the ___ ___. - Correct Answer return rate. Grit is washed in a snail to - Correct Answer wash off organics. A good Primary Clarifier removes __ to __% of settable solids. - Correct Answer 90 to 95%

Good Sludge has Lots of __ & ___ ___, a Few ___ and __. - Correct Answer ciliates & free swimmers, a few rotifers, and flagellates. What process is used to re-seed Aeration Basins and remove solids from Secondary Claifires? - Correct Answer Return Activated Sludge (RAS) A Sludge Volume Index (SVI) number of ___ is an indication of sludge bulking. - Correct Answer 180 mL/g Digesters show improvement by an increase in - Correct Answer methane, and a decrease CO Primary treatment uses - Correct Answer gravity to treat ___ and below is an oxygen deficient atmosphere. - Correct Answer 19.5% What will not affect the vacuum filter system? - Correct Answer Drum speed Information on preventive maintenance procedures, materials, and frequencies for plant structures should be taken from? - Correct Answer Manufactures literature What is the minimum surface loading rate on a trickling filter? - Correct Answer 1 MG/Acre/Day Standard Rate Filter What type of process requires scum from the final clarifier to be place in the digester? - Correct Answer Trickling filter and Rotating Biological Contactor (RBC) What is the assumed BOD removal rate used in plant design calculations for primary clarifiers? - Correct Answer 35% What is the name of the algae that is abundant in stabilization ponds? - Correct Answer Phytoplankton What regulates the RPM's on an air driven Rotating Biological Contactor (RBC)? - Correct Answer Air volume On a water lubricated pump, what should the seal water pressure be? - Correct Answer 5 p s i over stuffing box pressure Increasing the return rate of a conventional activated sludge plant has what effect on process control? - Correct Answer Decrease detention time, in aeration basin, raise dissolved oxygen, lower sludge blanket. If an employee, is guilty of misconduct,

According to 30 TAC Chapter 317, all pipe and fittings used in wastewater pressure mains shall have a minimum psi pressure rating of ________. - Correct Answer Carbon monoxide (CO) poisoning symptoms are ________. - Correct Answer When setting work goals for an employee, the goals should be ________. - Correct Answer As the population of a collection system increases, the ratio of peak flow to average daily flow will - Correct Answer decrease Pre- aeration of influent would aids in - Correct Answer flotation of grease In a normally operating trickling filter, the temperature difference between the atmosphere and the influent wastewater will - Correct Answer cause air to flow through the media and across the zoogleal mass Frequency of TCLP monitoring, for dry metric tons of sludge disposed of - Correct Answer 0 to 290, once per year, 290 to 1,500, once per quarter, 1,500 to 15,000, once per 60 days. 15,000 monthly. Essay: List and explain the functionality/role of each float for a lift station that has 2 pumps and 4 floats installed? - Correct Answer Essay: Explain the 5 major mechanical components of an activated sludge system? - Correct Answer Essay: Explain the advantages and disadvantages (or differences) between an oxidation ditch and activated sludge system? - Correct Answer Essay: What are the 6 major components of a Sewer System Evaluation Survey (SSES)? - Correct Answer What is the purpose, of a sanitary sewer, evaluation survey - Correct Answer A sewer system evaluation survey, is a systematic evaluation, used to investigate reports of excessive inflow , or infiltration sources, in a sewer system. The survey also assesses the flow rate, and the cost for rehabilitation, if said sources, are found to be excessive Advantage of wastewater stabilization ponds - Correct Answer low-cost technology, requires low maintenance, is highly efficient, mostly natural and sustainable.