Wastewater Class B Texas Study Guide Exam Questions Containing 194 Terms with Certified So, Exams of Water and Wastewater Engineering

Download Wastewater Class B Texas Study Guide Exam Questions Containing 194 Terms with Certified So and more Exams Water and Wastewater Engineering in PDF only on Docsity! Wastewater Class B Texas Wastewater Class B Texas Study Guide Exam Questions Containing 194 Terms with Certified Solutions 2024-2025. (Dark Back Ground for better Visibility and eye Care) The name of the State Agency responsible for enforcing pollution control laws in Texas - Answer: Texas Commission of Environmental Quality 1 Wastewater Class B Texas The term pathogenic means - Answer: Capable of causing disease The minimum separation between sewer lines and potable water lines is - Answer: 9 feet A licensed wastewater operator is a professional - Answer: consistently does best job possible, practices personal safety, strives to improve job knowledge, strives to keep the plant and collection system in the best appearance and working order An important step in testing a sample for Total Suspended Solids is - Answer: Filtering a sample The Biochemical oxygen Demand (BOD) of a sample is based on - Answer: Measuring the dissolved oxygen (DO) used The results of Biochemical Oxygen Demand (BOD) sample taken at a treatment plant tells the operator - Answer: How the plant was operating 5 days ago Which of the following are dangerous gasses that are likely to be present in lift stations and manholes? - Answer: Natural gas, gasoline fumes, hydrogen sulfide and carbon dioxide A preferred hydraulic method of cleaning sewer lines is - Answer: Hydro Jet Cleaner 2 Wastewater Class B Texas Non-point discharges are - Answer: discharges that have intermittent, dispersed flows having little or no control The Texas Water Code establishes the protection of water quality and quantity of the state by - Answer: setting stream standards, issues permits for discharges, identifies non-point source controls, and establishes water reuse. The wastewater plant operator is primarily responsible for - Answer: treating wastewater discharged into the community Chapter ___ of the Texas Water Code is the state law controlling water pollution and ___ authority to control discharges in Texas - Answer: Chapter 26 and Texas Commission of Environmental Quality The Texas Commission on Environmental Quality can revoke an operator's license if the operator - Answer: causes permit violation, falsifies records or neglects their duty If accidental discharge, bypass, or spill (SSO) of wastewater occurs the responsible party MUST notify TCEQ regional offices within ____ hours - Answer: 24 Aerobic Bacteria require_____ in the water for their metabolism - Answer: oxygen Anaerobic Bacteria _____ live with O2 present in the water for their metabolism - Answer: cannot 5 Wastewater Class B Texas Facultative Bacteria require__________in the water for their metabolism - Answer: either aerobic or anaerobic conditions Chemical characteristics of sewage include - Answer: solids, greases, dissolved oxygen, O2 Demand, pH, and gasses _________removes Total Suspended Solids (TSS) - Answer: filtration Inorganic solids include - Answer: sand, grit and minerals Organic solids include - Answer: organic materials from plants, animals or humans A good plant influent pH is about - Answer: 7.2 Dangerous gases are produced during bacterial decomposition of organics in wastewater. The main gasses are - Answer: Hydrogen sulfide, carbon dioxide and methane The majority of Dissolved Oxygen in raw sewage comes from - Answer: Potable Drinking Water Each person contributes approximately ______ lbs of BOD to the system daily. - Answer: 0.17 6 Wastewater Class B Texas Sources of waste water include - Answer: domestic, storm water, commercial, food processing, agricultural and industrial A sewer manhole provides access into the system for cleaning or service. A manhole is located - Answer: at changes in alignment, diameter, grade, direction and intersection New manholes must have an inside diameter of at least ______ feet and the entry access must be at least ____inches. - Answer: 4 feet and 24 inches In the past ____ was used to construct manholes. This product is prohibited for construction or grading today - Answer: brick and mortar Verified clay and Poly Vinyl Chloride (PVC) are the most common pipe materials used for sewer lines but other materials are available such as - Answer: ductile iron, cast iron, acrylontrile butadiene styrene (ABS) Concrete, polyethylene & asbestos concrete Whenever wastewater cannot flow to the treatment plant by _____ a _____ is typically used - Answer: gravity/ lift station The primary cause of stoppage in a collection system is _____ and _____ - Answer: grease/roots The _____pump is most commonly used in a lift station - Answer: centrifugal 7 Wastewater Class B Texas Landfill applied sludge must have a solids content of at least _________percent - Answer: 20 Calcium Hypochlorite (HTH) is a strong _______ and reacts violently with _________. - Answer: Oxidizer/Oil & Hydrocarbons When added to water chlorine forms _____&_______acid - Answer: Hydrochlorous and Hydrochloric When ammonia is present in wastewater and reacts with chlorine_________are formed - Answer: Chloramines Effluent dosage of chlorine in the contact chamber must produce a total combined residual of - Answer: 1.0 mg/L after 20 minutes Besides disinfection, chlorine has other uses at the wastewater treatment plant such as - Answer: Reduces BOD, Odor, Algae growth, Helps with Grease TCEQ allows the reuse of wastewater, some of these include - Answer: Irrigation, aquifer recharge, cooling towers and fire protection All reclaimed water piping must be _______in color - Answer: purple 10 Wastewater Class B Texas Before entering a manhole the operator should test for ________and oxygen levels and ________the manhole before entering. - Answer: all hazardous gasses and ventilate When a municipal wastewater effluent has a high nitrate level and low ammonia level this most likely means - Answer: the effluent has received a high degree of aerobic treatment Total solids in wastewater are the sum of - Answer: Settleable and volatile solids This treatment device is commonly used to separate and remove large solids from raw wastewater - Answer: A Mechanically raked bar screen ___________would have an adverse effect on the proper settling of solids in a clarifier. - Answer: A short circuiting flow pattern This test would give the best information on how efficiently a trickling filter was operating - Answer: Percent BOD Removal This trickling filter problem could be reduced by increasing the recirculation ratio - Answer: Filter files What gases are produced by the controlled anaerobic digestion of wastewater sludge's - Answer: Methane & Carbon Dioxide 11 Wastewater Class B Texas These diseases are caused by pathogenic organisms that may be present in raw wastewater - Answer: Hepatitis, typhoid, paratyphoid,dysentery, cholera, gastroenteritis, polio, hookworm and giardiasis During heavy rain it is possible that manholes and lift stations may overflow, discharge waste materials into roadways or ditches. This type of discharge (SSO) would be - Answer: considered an unavoidable discharge, a violation of the Texas Water Code, a bypass that must be reported within 24 hours and considered a health hazard An effective way for the collection system worker to prevent infection by waterborn pathogenic organism is to - Answer: Wear protective clothing and avoid direct contact with waste water _________will increase the chances that sewage will turn septic - Answer: Stoppages in the main line Extensive use of garbage disposals (grinders) in a community would likely have the following effect on the collection system - Answer: Increase the amount of flow, solids, and grease The minimum size for a gravity flow sewer line on city right-of-way and the minimum grade is - Answer: 6 inch and a grade of 0.50 percent 12 Wastewater Class B Texas Enforcement action from TCEQ may be taken if pollution or waste violates the Texas Water Code. Violations of Water Code may include - Answer: Unauthorized discharge, accidental discharge & health hazard Solids in wastewater are classified as - Answer: Total (TR), Suspended (TSS), Dissolved (TDS), Settleable (SS), Non-setteable, Floatable, Organic and Inorganic Total Suspended Solids (TSS) are those that - Answer: Can be filtered out Total Dissolved Solids (TDS) are those that - Answer: cannot be filtered out Settable Solids (SS) are those that - Answer: Settle out when left standing for extended periods of time Non-settleable Solids are - Answer: Small particles that do not settle Volatile Solids (VSS) are those that - Answer: Are determined by burning the residue from the Total Solids determination Inorganic Solids (ash) are those that - Answer: Consist of sand, grit, & minerals and can be suspended or dissolved Organic matter in wastewater can be ______or________and makes up approximately _______% of the total solids - Answer: Dissolved or Suspended / 65 15 Wastewater Class B Texas The typical pH of an influent entering the plant will vary from - Answer: 6.5 to 8.0 Acute toxicity occurs when - Answer: There is a rapid die off of treatment organisms Chronic toxicity occurs when - Answer: Certain microorganisms become inactivated but others continue to work resulting in a sick biological process A mechanical device that screens & cuts large solids in small particles - Answer: Cumminuter Detention time in wastewater typically refers to - Answer: The time sewage is kept in a sedimentation basis There are five (5) major components to a trickling filter - Answer: Filter floor, underdrain, walls, filter media, & distributer arms Zoogleal Mass refers to - Answer: A thick layer of jelly like slime where organisms bacteria, fungi, protozoa and ciliates thrive. The efficiency of a trickling filter is measured in - Answer: Percent BOD Removed Common operating problems with a trickling filter include - Answer: Ponding, Filter files, Odors, Clogging of Nozzles, & Snails 16 Wastewater Class B Texas Wastewater Stabilization Ponds are an approved process for wastewater treatment. Organic loading of Stabilization Ponds is typically - Answer: 35 lbs BOD/Acre/Day with a minimum of 30 days detention time Wastewater Stabilization Ponds work through a complex process which includes - Answer: Sunlight, Oxygen, Nutrients, Algae, and Bacteria Facultative Lagoons have two zones of treatment - Answer: an aerobic surface layer and an anaerobic bottom layer Typically one could expect ____ % BOD removal in a Facultative Lagoon - Answer: 50 Aerated Lagoons rely on ______ to provide ____and _____ - Answer: Mechanical aeration/ Aeration & mixing The most common method of dewatering and drying sludge is - Answer: drying bed Digester gas typically contains about ________%_______ - Answer: 65-75% methane The depth of sludge drawn to a drying bed should be - Answer: Approximately 9 inches 17 Wastewater Class B Texas In the activated sludge process, for the clarifier to do its job, the ____ must be retained long enough to allow ______ to settle and liquid to rise. - Answer: water/ solids In the activated sludge process, as more mixed liquor flows to the clarifier, the thickness of the sludge blanket will - 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 - Answer: Air lift pumps, centrifugal pumps, Diaphragm pumps, Screw pumps & Gravity Flow In the activated sludge process, no sludge process will work properly without - Answer: Regular removal of excess solids In the activated sludge process, Mass Balance refers to - 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 - 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 ___________. - Answer: Dividing/ Incoming BOD/ aeration tank 20 Wastewater Class B Texas In the activated sludge process, the term Gould Sludge Age refers to - 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 - 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 - 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 - 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 - Answer: Surface scum, Sludge blanket, Weir Flow, Rising solids, & Clarifier overflow In the activated sludge process, five (5) Important control parameters are - Answer: Dissolved Oxygen level, Aerator solids level, Solids quality, Rate of returned sludge, & Wasting rate 21 Wastewater Class B Texas In the activated sludge process, Dissolved Oxygen levels throughout the aeration basins are measured using a portable DO meter. The operator should keep DO levels between ______ and _______. - Answer: 2 mg/L and 4.0 mg/L In the activated sludge process, "Classic Bulking" is a common problem typically caused by - Answer: Low density sludge In the activated sludge process, Sludge Rising differs from "Sludge Bulking" and "Sludge Rising" is typically associated - Answer: Nitrification - De-nitrification process In the activated sludge process, techniques used to reduce "Frothing & Foaming" typically include - Answer: Adjusting sludge age, Reducing the amount of air, Spraying the frothing area with water, Applying de-foaming agents In the activated sludge process, floc is very important to the settling process. Floc is composed primarily of - Answer: Bacteria, Protozoa, Microscopic Animals, & Fungi In the activated sludge plants, the operator will experience problems. Some of the common Treatment plant problems include - Answer: Insufficent capacity, Equipment failures, Design inadequacies, Poor maintenance, & Inflow rates exceed plant capacities. 22