MA Wastewater Treatment Grade II Final Exam Test 2026

Wastewater MA Wastewater Treatment Grade II Final Exam Test 2026 Why is the handling and disposal of sludge a complicated problem? Sludge often consists of toxic chemicals What adjustments should be made to a firm, dry cake, as it related to sludge dewatering? Generally speaking, no adjustments are necessary Successful operation of gravity filters depends on: Even dispersal of wastewater throughout the filter Unit processes often used for sludge dewatering are: Pressure filtration A Parshall Flume is generally used to: Measure flow The following is NOT an example of a flow measuring device: Manometer The flow delivered to a treatment plant can be measured by a: Parshall Flume The most reliable type of wastewater flow measuring device is a Mag Meter Wastewater flow measurements are commonly used to: Establish the amount of pollutants for mass-based discharge standards A Rotameter is a reliable device for measuring flows of Treated wastewater The head on a wastewater flow measuring flume can be monitored by a Bourdon tube Conductivity tubes are used to maintain, repair, and troubleshoot Water systems A PLC could typically control Wastewater Wastewater The addition of acid or caustic to a tank Floats and level probes should be checked to make sure the motors are starting and stopping at the correct liquid level and/ or also Tested weekly for proper operation You walk into the treatment room and notice the the pH chart is fixed at 7, what should you check first? pH probe wiring The alarms keep going off for a pH system. When you check the system, you notice that Tank 2's pH is 5.00 and the final pH is 10.5. What should you check first Tank 2's mixer You walk into the treatment room and notice the alarm going off and Tank 1, Tank 2, and the final pH all read the same: 11.00. Both acid pumps (Tank 1 and Tank 2) are running. What do you check first Reagent level and reagent pump prime When calibrating pH probes always Clean before calibration You calibrated a pH probe and the response was slow. What is the cause Bulb is coated Which of the following wastewater characteristics can be monitored continuously pH What is the difference between digital and analog meters Digital is easier to read A pH recorder indicated a 10.0 when a pH of 8.0 is desired. Adding acid makes no difference. A portable pH meter indicated the pH is less than 10. Which item would you check first Sensor Sulfide precipitation of metal is More expensive than hydroxide precipitation What is drag-out Plating solution carried over the rise tank Which is a common compound used for oxidation Wastewater Wastewater Sodium hypochlorite What is cyanide converted to during treatment Nitrogen and Carbon Dioxide Hexavalent Chrome is Toxic to the environment A reducing agent is used to treat Chromium Chemical precipitation of metal wastes generated by the metal finishing industries is often accomplished using Hydroxide If cyanide solutions reach acid pH: Hydrogen cyanide is released Metal finishing wastes are usually treated chemically because the contaminants are generally not only resistant to biological treatment but are frequently _____ biological organism. Recovery of metals Samples collected for heavy metal analyses can be preserved by the addition of: Nitric acid What is a source of radioactive wastes in a treatment plan influent? Labs and hospitals A common contaminant from metal finishing process which arises in the drag out waste is cyanide. In the treatment of cyanide, chlorine is used: As an oxidizing agent Zinc and Chrome hydroxide treatment requires: pH control A waste stream with high _____ would most likely indicate a waste stream containing metal finishing and plating wastes. Dissolved solids Precious metals are recovered by Evaporation Wastewater Wastewater What is an example of a pickling acid Nitric acid Cost effective treatment for many metals Hydroxide precipitation The wastewater from metal finishing industries may contain Cyanide wastes A standard method of treating chrome waste from a metal finishing process involves changing the pH and the addition of chemicals to cause a reduction of the chrome from hexavalent to trivalent and the ultimate precipitation of chrome hydroxide. What is the pH range relating to the least solubility of chrome? 7-9 In the physical-chemical treatment of chromium waste from a plating operation, typically the first step in the treatment process is: Lower the pH In the removal of cyanide in metal waste streams Bleach is added An oxidizing agent used to treat industrial wastewater is: Hydrogen peroxide What first step is common to the treatment of chromium, cyanide, and other industrial wastes pH adjustment Sodium Metabisulfite is used as a Reducing agent Metal-plating industries use ion exchange for ________ By-product recovery CN is the chemical formula for Cyanide Neutralization of metal plating wastes is very complicated when applied to continuously flowing waste streams which vary in flow rate, free acid, or caustic content and: pH levels Wastewater Wastewater Samples collected for cyanide analysis should be preserved by adjusting to pH to: Greater than 12 Oxidation-reduction reactions require Chemical oxidizers Procedures used for shut down and subsequent start-up of processes for treating industrial waste vary with: Influent flow rates PVC pipe will not be attacked by Bacteria The first step when performing corrective maintenance is to: Identify the problem A preliminary practice used by industry to reduce the quantity of industrial wastes is: Recovery If no wastewater is flowing through a micro screen, the cause of the problem could be: Faulty drive chain In industrial wastewater pretreatment systems Sludges are produced by coagulation and flocculation Following coagulation, the next step in a physical-chemical treatment is called Flocculation Why is sulfide precipitation useful? High reaction rate A major objection to the use of chemical precipitation processes to treat industrial waste streams is the Quantity of sludge The optimum pH for a coagulant used to treat an industrial waste must be determined Experimentally The most accepted testing procedure for both coagulants and the determination of optimum coagulation is the Jar test A jerky or inoperable sludge collector could be caused by Wastewater Wastewater Sludge blanket too deep When treating the same wastewater stream, which alkaline substance will produce the least amount of sludge Caustic soda In industry, effective ways to reduce the amount of water requiring treatment is Modify the manufacturing process Generally speaking, the first step in a wastewater pretreatment process is Equalization Which of the following are considered acids Carbon Dioxide A pH of 8 is how many times more alkaline than a pH of 7? 10 times greater Alkalinity is the capacity to neutralize ______, that is to absorb _______ ions with sufficient pH depression Acid, Hydrogen Which pH has the highest hydrogen ion concentration The lowest pH If the pH of a waste stream is 9.8, the waste stream is: Basic Buffers are important in wastewater treatment because they: Are stable for calibration Slaking is a process of adding Water to quicklime pH meters measure Hydrogen ion concentration Adjustment of pH may utilize the following chemical Sodium Hydroxide Why must lime slurry mixing equipment and pumps be kept clean at all times? Because lime slurry is sticky, and material will gum and stick The purpose of a maintenance record keeping program is to help Plan to replace parts Wastewater Wastewater Typically, motors of 100 horsepower or less should not be started more than Four or five times per hour Positive displacement pumps should be started, ______, to prevent a loss in prime. With discharge valve open Centrifugal pumps include Impeller Pump maintenance includes Checking the operation temperature of the bearings What is the main purpose of a lantern ring? Allows water to enter packing A gear pump is considered a Positive displacement pump Always close the ______ valve when priming a positive displacement pump. Wrong, all valves are open What type of valve is used for throttling flow? Butterfly When shutting down a pump for a long period of time: Disconnect power, lockout, shut all suction, water seal, and discharge lines and drain the pump Stuffing boxes as compared to mechanical seals are Easy to rebuild but leak Never throttle a pump with the ______ valve Suction Cavitation is caused by Air leak on the suction side of the pump Check valves are used in connection with centrifugal pumps in order to: Prevent water in the discharge line from flowing back The most reliable type of metering pump is a Peristaltic When starting up a positive displacement sludge pump Suction valves should be open and the discharge valve open Wastewater Wastewater If a high head pump sounds like it is pumping rocks, you should Restrict discharge If an electrical motor fails to operate, the most likely thing to do is: Push the reset In repacking a centrifugal pump, the correct placement of the water seal ring is: Placed so that it lines up with the water seal pipe hole in the stuffing box Improper rotation in a centrifugal pump may cause Reduced flow A pump which discharges the same volume from each stroke is called a Positive displacement pump In packing a modern gate valve, the operator first opens the valve all the way and then removes all the old packing from the stuffing box. He then cleans the valve stem and polishes it with a fine emery cloth. After polishing the stem, he cleans it with an oily cloth. The new slit-ring packing is installed after which a few drops of oil are placed on the stem and then the gland is tightened down on the packing. What, if anything, did the operator do incorrectly? He did nothing wrong In packing a modern gate valve, the operator first opens the valve all the way and then removes all the old packing from the stuffing box. He then cleans the valve stem and polishes it with a fine emery cloth. After polishing the stem, he cleans it with an oily cloth. The new slit-ring packing is installed after which a few drops of oil are placed on the stem and then the gland is tightened down on the packing. What, if anything, did the operator do incorrectly? Should have left the plug out for a short period of time A peristaltic pump is a type of ______ pump Positive displacement The water supplied to the water seal on a packed pump should be _____ in relation to the liquid being pumped. 5-10 PSI Greater Which would be the cause for a pump to draw unnecessarily high amperage Packing too tight Wastewater Wastewater In order to comply with safety regulation, al couplings on pumps must be Guarded Which of the following precautions must be taken before attempting to maintain or repair a surface aerator? Shut down the aerator All gate valves have ______valve stems Both rising stems and non-rising stems Which of the following items may be discharged into a municipal sanitary wastewater collection system? A substance that will Result from the pretreatment of an industrial waste How long should most monthly operational reports be saved? 5 Years Alarm systems at wastewater treatment facilities in Massachusetts shall be tested: Twice annually At a grade 4 wastewater treatment facility the chief operator must be a grade __ and the assistant chief must be a grade ___. 4, 3 Once effect of an unregulated industrial waste discharged to a municipal wastewater treatment plant might include: Anaerobic digester upset The process to treat conventional wastes at a POTW is considered Complex to treat A level 3 plant needs the chief and the assistant chief operators at what operator grade, respectively? 3, 2 If a wastewater treatment plant grade cannot be found who determines the grade? The DEP Industrial wastewater treatment operators need to understand the sources and quantities of industrial waste so that they can _____ problems caused by industrial discharges Identify Wastewater Wastewater Pollutants that are compatible with the operation of a POTW include: Ammonia A representative from the Division of Water Pollution Control can inspect a wastewater treatment facility _____________. At all reasonable times What is the state specified reference for conducting laboratory analysis at treatment facilities Standard Methods for the Examination of Water and Wastewater Categorical regulations apply to All industrial dischargers to POTW's Which of the following is not a detrimental effect that industrial waste waters may have on a POTW? Equalization An advantage of biological treatment processes is that the microorganisms can easily: Developing an operational strategy in which toxic waste is discovered in the influent to the treatment plant: Reduces cost due to damage to equipment or fines How often should a staffing plan be updated Every 2 years The odor of pure methane gas, CH4 is that of Pure methane gas has no odor Major injuries in industrial wastewater treatment result from Spills/Falls Major injuries in industrial wastewater treatment result from Spills/Falls When a person has suffered a physical or emotional shock, you should Telephone for help and talk calmly to him or her while waiting for help to arrive The three things needed for a fire to occur are Ignition, fuel, oxidizer Which of the following is not a route of entry for hazardous chemicals Digestion Wastewater Wastewater The first thing an operator should do if concentrated sulfuric acid is spilled on their arm is Rinse the area with water for at least 15 minutes In an emergency situation involving a chemical, _______ should be available The SDS Has a vapor density less than 1 According to OSHA, all humans should not work in an atmosphere where the oxygen level is less than 19.5% While waiting for help to arrive, the best thing to do for a conscious injured person is Keep the person as warm and calm as possible Which of the following statements correctly identifies the fire type for each respective fire Computer Fire - C; Trash Fire - A; Magnesium Fire - D; Gasoline Fire, B Duties of an attendant during a confined space entry DO NOT include: Entering the space to help an entrant in an emergency A "lockout procedure" is A policy for ensuring that electrical and mechanical equipment remains de-energized during maintenance Of the following, the most important thing in a treatment plant safety program is: Proper training of employees The safest way to handle emergencies is to Plan for them in advance Corrosive chemicals include Bases When a SCBA cylinder is running low on air, among the noticeable affects are: Continuous sounding of the alarm A pumps station explodes, and four workers are missing when you arrive at the scene. What do you do first? Call fire department and police Wastewater Wastewater Which of the following are the only currently accepted procedures to control bleeding in a first aid situation? Direct pressure Explosive gases may be detected by LEL meters Which of the following should NOT affect the fit of respiratory protection Perspiration . If polymer is spilled, it will make the floor slippery. This may be cleaned up using ______. Bleach SDS Stands for... Safety Data Sheet A poor safety program will have: No assignments or responsibility What two gases besides methane and hydrogen sulfide are of concern to the IWTO? Oxygen and carbon monoxide According to RCRA, the four criteria which indicate that the waste is hazardous are: Ignitability, corrosivity, reactivity, toxicity Disaster planning is Useful in reducing confusion in the event of a disaster The wastewater operator is responsible for being informed of the Chemical hazards for the chemicals used The best preventative measure against oxygen deficiency or explosions is Ventilation Gases, including toxic and hazardous gases, whose vapor density is greater than one will tend to Accumulate and displace oxygen in low areas The main purpose of a confined space entry permit is to Ensure the use of safety precautions and safe work procedures What problem(s) may occur if the sludge blanket in a Dissolved Air Flotation (DAF) Unit is allowed to build up and drop too far below the surface of the liquid Wastewater Wastewater Solids will pass under the effluent baffle and into the discharge Inorganic dissolved solids can be removed from waste streams by Ion Exchange Brewery wastes are readily biodegraded in a Trickling filter With a dissolved air floatation clarifier, the thickened sludge leaves the unit from the: Top In the plate and frame press filtering process, as the cake builds up between the plates, the filtrate: Decreases Benefits of a Lemella Clarifier over conventional sedimentation tanks include Smaller foot print Activated carbon is used in industrial wastewater treatment primarily to remove: Cyanide Activated carbon can be manufactured from Coconut shells Which of the following treatment processes has historically been associated with water desalination Volatile organic chemicals What happens to a centrifuge's waste stream if the optimum feed is exceeded Centrate solids increase Electrodialysis is used to treat wastewater from ________ Electroplating facilities Ion exchange is used to Recover metallic ions Activated carbon steel pressure containers must be lined with an epoxy or resin to: Prevent corrosion of the container To determine if the screens in an activated carbon column are doing an efficient job, an effluent sample is collected daily and analyzed for: Carbon fines Which of the following is not a physical method of wastewater treatment? Wastewater Wastewater Electrodialysis Which of the following treatment methods does not rely on particle size? Precipitation Phenols are removed by Activated carbon Which of the following industrial wastewater pollutants can be treated by activated sludge? COD Volume reduction of wastewater from a plastics manufacturing plant can be achieved by Evaporation Grab samples are used when testing for Dissolved gasses Why is automatic sampling equipment difficult to operate They require cleaning and calibration When sampling, all representative samples must be preserved with _____ while being transported to the laboratory for analysis Ice What is the best way to calculate coagulant and polymer dose? Jar Testing A representative sample Is a sample of the overall situation Where does an operator find the information for the proper sampling locations? NPDES permit Why are samples preserved at or below 6 degrees celcius Minimum bacterial activity at this temperature A jar test can be used to determine The most economical coagulation doses Samples preserved in basic pH include Sulfides Wastewater Wastewater To measure the pH of the effluent from a waste treatment plant, the effluent sample must be analyzed: Immediately A poor sampling point is a location that May contain hazardous atmosphere A composite sample Is based on flow and/or time Maintenance of automatic sampler requires: Constant maintenance to achieve accurate results Why is a "chain of custody" for samples important? To legally prove that Responsible people had possession of the sample at all times Which of the following may interfere with the analysis of phenols? Sulfide Which of the following waste streams contain significant quantities of organic material? Domestic wastewater Industries discharging hexavalent chrome include Leather tanning Which chemicals used in an industrial facility can end up in the waste treatment system? Any chemicals used within the facility What pollutant would you be most likely to see in wastes from a textile manufacturer? High temperature What is a source of pollutants in storm water runoff? Products which have spilled onto the ground Wastewater generated from papermaking processes include: Spent sulfite liquid How is the concentration of contaminants (pollutants) typically measured in the wastewater industry Mg/L Convert 4 PPM to mg/L (1L = 3.14 Gallons, 100 mg = 1 g, 454g = 1 lb.) 4 mg/L Wastewater Wastewater Convert 45 feet of water pressure into psi 19.5 psi A 25,000-gallon waste storage tank should release the wastewater at what rate to ensure a fairly uniform discharge during a 12-hour period? 35 g.p.m A chemical feed pump is set to deliver 75 gallons per day. What is this feed rate in milliliters per minute? 197 ml/min A 30,000-gallon tank is full of a dry chemical with a specific gravity of 1.35. What is the weight of the contents of the tank? 337,770 lbs. An industrial waste flow of 0.075 MGD require a chlorine dose of 8.5 mg/L. What should be the chlorinator setting? 5.3 lbs./24 hr. What is the volume of a tank 10 feet in diameter and 25 feet tall? 14,680 gal The discharge pressure gauge on a pump reads 23 psi. What is the discharge pressure in feet? 53 ft What is the percent COD removal by an industrial waste treatment process if the influent COD is 285 mg/L and the effluent COD is 96 mg/L? 66% The rectangular tank, 10 ft high by 20 ft wide by 40 ft long, is to be completely painted inside with two coats. It has no cover, and each gallon covers 50 sq. ft. How many gallons of paint are required? 48 In wastewater treatment plans, the flow is usually recorded in MGD The entire surface of a free-standing cylindrical tank with an exposed flat bottom must be painted. The tank doesn't have a top cover. The tank is 45 inches in diameter and 18 ft high. What is the total surface area to be painted? (Interior and exterior) Wastewater Wastewater 424 sq. Ft. What is weight of wastewater in a cubicle tank 10 feet on each side? 62,380 lbs. Laws Statutes, and Acts Created by our elected officials. They declare, command, or prohibit something, but their wording is general in nature POTW Publicly owned treatment works. Receiving Waters Any body of water that 'receives' waters that are discharged by a POTW CFR Code of Federal Regulations What are the characteristics of the regulated waste streams in the pulp and paper industry High in BOD, COD, and suspended solids What are the characteristics of the regulated waste streams in the battery manufacturing industry Lead and Acids What are the characteristics of the regulated waste streams in the fermentation industry High BOD and mild acids What are the characteristics of the regulated waste streams in the Petroleum industry High suspended solids, dissolved solids, and oils What are the characteristics of the regulated waste streams in the Iron and Steel industry Toxic organics, dissolved salts, oils, acids, and solvents What are the characteristics of the regulated waste streams in the Dairy Industry High BOD and suspended solids What are the characteristics of the regulated waste streams in the plastics industry High temperature, oils, and solids What are the characteristics of the regulated waste streams in the tanning industry High salts, high BOD, and suspended solids Wastewater Wastewater What are the characteristics of the regulated waste streams in the meat packing industry High BOD and suspended solids What are the characteristics of the regulated waste streams in the metal finishing industry Heavy metals How are suspended solids removed? Settling How are oil and grease removed? Skimming How is BOD (Biochemical Oxygen Demand) removed? Aeration and microorganisms List the steps of a POTW in order: Preliminary treatment, Primary Treatment, Secondary Treatment, Tertiary Treatment, Chlorination and Dechlorination ANEROBIC Conditions Conditions occurring in the presence of oxygen ANAEROBIC Conditions Conditions where there is no oxygen present When is it most appropriate to use a V-Notch Weir? When flow is low What is a staff gauge used for? What are the drawbacks Used to measure to measure water height; difficult to read if foam is present or if operator can't get close enough to view readings SECONDARY flow elements Installed in stilling wells to reduce turbulence found in a flowing channel. From a safety standpoint, microscreen mechanisms should be: Enclosed In electrical wiring, the ground wiring is normally which color? Green What is normally used to treat laundry wastes Wastewater Wastewater HCl The amount of chlorine that can be fatal in just a few breaths is: 1000 mg/L Which of these devices would be best to measure GAS flow Rotameter What is Binding? When a screen filter clogs because some/all of it's pores are plugged up A CATION is _____ charged Positively An ANION is ____ charged Negatively At what pH is acid strong enough to dissolve concrete? pH 5.0 How is pH 1 expressed in moles per liter 0.1 or (1.0 x 10^-1) How is pH 10 expressed in moles per liter 0. or (1.0 x 10^-10) Efficient sludge withdrawal from a primary settling tank is about: 4-6% solids How many parts of base would be needed to adjust pH 3 back to pH 7? 10,000 parts of base Rotameters Use gravity and fluid hydraulics across a varying area to measure flow. Neutralizing Adding acid or base to a solution to bring the pH closer to the equivalence point. Flocculation After coagulation, allowing larger suspended solids to form or agglomerate through the use of additional chemicals/polymers along with gentle mixing. Short Circuit A shortened flow path that prevents proper treatment of water needing to be treated. Oxidation reduction potential (ORP) Wastewater Wastewater A measurement of the ability of a solution to either oxidize or reduce something Low ORP Between 0 and 200 High ORP Between 500 and 900 Wastewater