Wastewater Operator Certification Grade 1 Study Guide: Questions and Answers, Exams of Water and Wastewater Engineering

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Wastewater Operator Certification Grade 1 Study Guide

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WasteWater Sources & Characteristics: What is the most common reason for a wastewater to contain intermittent large amounts of sand, gravel, and grit? - storm events WasteWater Sources & Characteristics: Combined wastewater is defined as - sanitary wastewater and stormwater runoff WasteWater Sources & Characteristics: In general, the solids content in wastewater is about - 0.1% WasteWater Sources & Characteristics: In general, what is the % of suspended solids in the total amount of solids - 30% WasteWater Sources & Characteristics: Generally, the % of dissolved solids in the amount of total solids is about - 70% WasteWater Sources & Characteristics: Which type of organisms would most probably be associated with poor treatment or young biomass - amoebas WasteWater Sources & Characteristics: Which type of organisms would most probably be associated with very clear plant effluent. low BOD and low amounts of suspended solids - stalked cilates Basic WasteWater Treatment: Aerobic bacteria will reproduce and live in an environment that contains only - oxygen Basic WasteWater Treatment: Anaerobic bacteria will reproduce and live only in an environment that completely lacks - free or dissolved oxygen Basic WasteWater Treatment:

The biochemical oxygen demand (BOD) test usually has a specific time of - 5 days Basic WasteWater Treatment: An Imhoff cone measures - volume of settleable solids Basic WasteWater Treatment: Septic conditions are caused by - anaerobic bacteria Basic WasteWater Treatment: Scum is usually removed in the _____treatment stage - primary Basic WasteWater Treatment: When domestic wastewater enters natural waters, what species deplete most of the oxygen

• aerobic bacteria Basic WasteWater Treatment: Once the oxygen is depleted in a natural body of water, which organisms take over? - anaerobic Basic WasteWater Treatment: The major gas produces by anaerobic decomposition is - methane Wastewater Treatment Facilities: Another name for promary treatment is - sedimentation Wastewater Treatment Facilities: Digester gas is_______when mixed with air the the proper proportions - extremely explosive Wastewater Treatment Facilities: A pond that is used to treat raw wastewater is called - a waste stabilization pond Wastewater Treatment Facilities: A pond that has an aerobic top layer and an anaerobic bottom layer is called - a facultative pond Preliminary Treatment:

What is the angle of the bars on a manually cleaned bar screen? - 30 degrees Preliminary Treatment: What is the angle of the bards on a mechanically cleaned bar screen - 45-60 degrees Preliminary Treatment: What is the ideal wastewater velocity in FPS through a screen channel? - 1.5ft/s Preliminary Treatment: What is the ideal wastewater velocity in FPS for grit removal in a grit chamber - 1.0 ft/s Preliminary Treatment: In general, what is the water content of screen material - 80% Preliminary Treatment: What is the wastewater velocity range in FPS for grit removal in a grit chamber? - 0.7 - 1. ft/s Racks, screens, comminutors and Grit removal: Which one of the following chemicals gives water its greatest capacity to neutralize acids? - hydroxide Racks, screens, comminutors and Grit removal: The bar rack is used - when the bar screen is out of service Primary Sedimentation: Typically, what is the average detention time for wastewater in a primary clarifier? - 2 hr Sedimentation and Flotation: Name one gas this irritates the "eyes" - chlorine Primary Sedimentation: Activated sludge clarifiers accept material to be settled from - an aeration tank Primary Sedimentation:

According to CWA, secondary treatment is defines as a wastewater plant producing an effluent that has no more than____total suspended solids and no more than_____BOD5 - 30 mg/L, 30 mg/L Primary Sedimentation: The color of bio film on a rotating Biological Contactor would appear____under normal operating conditions - gray Activated Sludge: A primary effluent and returned activated sludge mixture is called - waste activated sludge Activated Sludge: The mixture of organisms and solids in water that is removed from the settling tank is called - mixed liquor Activated Sludge: Under normal operating conditions, what color is activated sludge - dark chocolate brown Activated Sludge: What test(s) could an operator use to make process changes immediately if a problem develops - COD test Activated Sludge: The main "workers" in the activated sludge process are - bacteria Activated Sludge: A yellow gas flame from a digester's waste gas burner may indicate a poor quality gas with a - high CO2 content Waste Treatment Ponds: Ponds used in series after primary wastewater treatment are sometimes called - oxidation ponds Waste Treatment Ponds: The most common type of pond is - facultative pond

Waste Treatment Ponds: Which one of the following nuisance organisms is controller simply by the water surface being disturbed by wind or currents? - mosquitoes Waste Treatment Ponds: When is the Dissolved Oxygen in a waste pond the lowest? - sunrise Odor Control: What would be the most likely solution in the influent to a wastewater treatment plant has an H2S order? - add treatment chemicals Phosphorus Removal: That is the main reason why wastewater treatment plants remove phosphorous from their effluent before discharging to a lake or river? - the reduce the growth of algae Disinfection: What is the color of liquid chlorine? - amber... Disinfection: How many times heavier than air is chlorine gas? - 2.5 times Disinfection: Free available chlorine consists of - dissolved chlorine gas, hypochlorous acid, and hypochlorite ion Disinfection: The fusible plug on a chlorine cylinder will start to melt at approximately? - 160 degree F Wastewater Solids Processing: This solids retention treatment method usually has 20 days of retention time: - aerobic digestion Wastewater Solids Processing: The solids treatment methods processes solids in a sealed unit: - anaerobic digestion Wastewater Solids Processing:

The solids treatment method produces methane gas that can be used in other plant processes: - anaerobic digestion Wastewater Solids Processing: This solids treatment method cures the final product and then it may be applied to farmlands - composting Wastewater Solids Processing: The solids treatment method uses evaporation but also requires a great deal of labor. - sand drying beds Wastewater Solids Processing: The solids treatment method uses a partially submerged rotating drum - vacuum filter Wastewater Solids Processing: These solid treatment methods use a coagulant polymer and pressure - belt filter and plate Sampling, testing & reporting Tests such as pH, temperature and dissolved oxygen should always be performed within____after collection - 15 min Sampling, testing & reporting When calibrating a pH meter, the buffers used should bracket the expected pH and ______ - be at least 2 pH units apart Sampling, testing & reporting A test method for determining dissolved oxygen is the______ - azide modification for the Winler titration method Sampling, testing & reporting How long can a dissolved oxygen sample wait for analysis using the modified Winkler method, if it is preserved with sulfuric acid? - 8 hr Sampling, testing & reporting BOD5 samples can be preserved by - storing them in a refrigerator above freezing and up to 4 degrees C

Sampling, testing & reporting The maximum holding time for preserved BOD5 samples is - 2 days Sampling, testing & reporting Which one fo the following tests is least likely to effectively help an operator control a waste plant's process? - BOD 5 Sampling, testing & reporting The maximum holding time for a preserved total suspended solids sample is: - 7 days Sampling, testing & reporting Generally, the state regulatory body must be notified of all unusual or extraordinary discharges by telephone within: - 24 hours Sampling, testing & reporting Generally, the state regulatory body must be notified for any noncompliance that could adversely affect that state's waters or that could endanger public health within: - 24 hours Maintenance: Electromotive force (emf) is also known as - voltage Maintenance: Electron flow is measure in - amps Maintenance: what type of fuses would most likely be used to protect a meter? - dual-element fuses Safety: What class of fire involves electrical equipment? - class c Safety: When a permit is required to enter a confined space, who may sign the permit? - entry supervisor Safety:

Which one of the following is a measure of a materials' opposition to the flow of electric current? - ohms Safety: What class of fire involves oil and grease? - class B Safety: Why is it essential to ventilate a valve before entry - remove dangerous gases Safety: The primary purpose of check vales is to prevent - water from flowing in 2 directions Safety: Which one of the following infectious diseases is NOT transmitted by wastewater a. tetanus b. tuberculosis c. AIDS d. polio - the acquired immune defiency syndrome AIDS virus Safety: Which one of the following gases is least likely to collect in a below-ground vault? - carbon monoxide Safety: When working in a manhole, your vehicle, whenever possible, should be placed - between the manhole and oncoming traffic Safety: OSHA requires that adequate protection, such as shoring, be placed in any trench that is - 5 ft or greater in depth Safety: How far back from the opening of a trench should soil be excavated from that tench be placed - 2 ft at least Safety:

In a trench, ladders are required every - 25 ft Safety: How many ladders are required to be in a 5-ft deep trench when 6 people are working down the trench - 6 ladders Safety: which is not an essential ingredient for all ordinary fires? a. ignition source b. fuel c. heat d. oxygen - ignition source Safety: If some clothes are on fire, what class of fire is it? - class D Safety: If some magnesium is on fire, what class of fire is it? - 3 Safety: What is the minimum number of people that should be on-site working at a confined space site? where one of them is entering a manhole - 3 Safety: What type of fire extinguishers should be in pump stations - A-B-C chemical type Basic Chemistry: What piece of laboratory glassware is primarily used to mix checmicals and measure approximately volumes? - beaker Basic Chemistry: The electrical potential between two points is measured in - volts Basic Chemistry: What is the most common use today for a positive-displacement pump - chemical feed pump

Basic Chemistry: Which lab glassware will give the most accurate measurements of liquids - burettes Basic Chemistry: Which lab glassware is used for measuring volumes - graduated cylinders Basic Chemistry: People working in and around wastewater must be immunized for - tetanus Basic Chemistry: Which lab tests has a zero holding time - chlorine residual Basic Chemistry: Which one of the following statements concerning colloids is false? a. solutes have a greater effect on freezing and boiling points of liquids than do colloids b. only very small colloids will pass through a semipermeable membrane c. the average wavelength of white light is smaller than the dimensions of colloidal particles d. dialysis is the separation of colloids from solutes through a semipermeable membrane - d. dialysis is the separation of colloids from solutes through a semipermeable membrane Basic Chemistry: Describe "colloids" - an ion opposite in charge to a colloidal particle will force its way into the colloidal particle Basic Chemistry: Water is used as a standard because it has unique properties and is readily available in its pure state. Which standard is not correct? a. Celsius scale b. the calorie c. the kilogram d. specific gravity - the kilogram Basic Chemistry:

What acids are formed when water reacts with nonmetal oxides? a. acid hydroxides b. acid anhydrides c. acid oxides d. acid hydrates - acid anhydrides Basic Chemistry: Which one of the following is not a hydrate: a. alum b. blue nitrate c. sodium nitrate d. ferrous sulfate - sodium nitrate