Wastewater Grade 2 t/f

Wastewater Grade 2 t/f Complete Solutions Hydraulic loading to a facultative wastewater pond is measured in units of Inches/day Ans- True An Imhoff cone is often used to measure the effectiveness of primary sedimentation Ans- True A well-operating primary clarifier will generally remove nearly all settleable solids Ans- True The trickling filter recirculation ratio is calculated as follows Qr/Q Ans- True Chlorine dose = Lbs of chlorine/day divided by the flow in MGD Ans- False needs 8.34 A combined sewer carries domestic waste , industrial waste and storm water Ans- True Algae use oxygen at night in a facultative pond Ans- True The pH of digesting sludge in a healthy anaerobic digester should be near 7.0 Ans- True Percent volatile solids reduction equals : IN-OUT over IN-(IN x OUT) X 100% Ans- True A chlorine dose of 5 ppm or mg/L is equivalent to adding 5 lbs. of chlorine per million pounds wastewater flow Ans- True The main function of a secondary digester in normal operation is to allow liquids and solids to separate Ans- True Poor grit removal would affect the operation of a anaerobic digester Ans- True BOD removal efficiency in a well-operating primary clarifier is generally in the range of 25-40% Ans- True The M in the F to M ratio refers to the pounds of mixed liquor suspended solids under aeration in an activated sludge aeration tank Ans- False A barminutor may be set to start automatically based on a loss of head pressure through this device Ans- True Ppm ( parts per million) and mg/L are essentially equivalent units Ans- True The terms "high rate" and "low rate" refer to the rate at which gas is produced in an anaerobic digester Ans- False A grit chamber with a flow velocity of 0.2 ft/sec may allow a significant quantities of volatile material to setle out Ans- True Secondary wastewater treatment processes generally involve the aerobic decomposition of organic matter Ans- True Preliminary wastewater treatment is used to protect pumping equipment and to facilitate subsequent treatment processes Ans- True Oxygen may be referred to as either combine oxygen or free molecular oxygen Ans- True Solids in a wastewater effluent may undergo aerobic decomposition in the receiving water if dissolved oxygen is available. Ans- True The MPN test measures the number of pathogens in a wastewater effluent Ans- False Wastewater treatment ponds that receive raw wastewater are called stabilization ponds Ans- True Pre-aeration of raw wastewater may result in better removal efficiencies in the primary clarifier AnsTrue Domestic wastewater contains approximately 0.1% Total solids. Ans- True A well-operating anaerobic digester should have a CO2 concentration of more than 40% Ans- False Wastewater having a pH of 7.3 is slightly basic or alkaline Ans- True Gas production in an anaerobic digester results from the destruction of organic solids Ans- True Pre- chlorination of raw wastewater requires that a chlorine residual of at least 0.5mg/L be attained in order to assure odor control Ans- False Velocity in a grit chamer may be controlled by a proportional weir Ans- True The only function of flights in a rectangular sedimentation tank is to push the settled sludge toward the sludge hopper Ans- False Percent efficiency of solids or BOD removal is calculated using the following formula: IN-OUT / IN X 100 Ans- True Velocity is an important consideration in the operation of a collection system or a grit chamber AnsTrue One acre-ft of water contains 45,336 ft cubed Ans- False MGD and ft cubed/sec are both units of flow Ans- True BOD5 and SS are both used as measures of the strength of wastewater Ans- True Hydraulic loading to a clarifier is expressed in units of gallons per day Ans- False The solids in primary sludge contains both a volatile and fixed part Ans- True Chlorine feed rate and chlorine residual are both usually expressed in units of ppM Ans- False SVI is a measure of the rate at which activated sludge mixed liquor settles Ans- False A shear pin that constantly breaks should be replaced with a pin of greater strength Ans- False Septic sludge probably have a low pH Ans- True When computing anaerobic digester organic loading one must take into account the loss of solids in the digester supernatant Ans- False The F in the F to M ratio may be measured as either BOD or COD Ans- True An anaerobic digester is generally equipped with a combination pressure-vacuum relief valve Ans- True Extended aeration activated sludge plants are designed to have aeration tanks that can hold approximately one day's flow Ans- True A 5 foot deep facultative pond is usually mixed with floating aerators during cloudy days Ans- False A parshall flume measures velocity of the influent flow Ans- False When BOD and COD are measured on a primary effluent sample the BOD will generally be greater than the COD Ans- Fals