Waste Water Operator Treatment 1 Certification Study Guide Grade 1 Q&A

Waste Water Operator Treatment 1 Certification Study Guide Grade 1 Q&A 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 - 1.4 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