Wastewater Class 4 Exam Virginia| 100 questions| with complete solutions

In an electrical circuit, the grounding wire is indicated by which color? Correct Answer: Green According to the Ohms Law, which electrical unit measures pressure? Correct Answer: Volts According to the Ohms Law, which electrical unit measures resistance? Correct Answer: Ohms According to the Ohms Law, which electrical unit measures current? Correct Answer: Amps How do you convert cubic feet to gallons? Correct Answer: Multiply by 7.48 How do you convert gallons to pounds? Correct Answer: Multiply by 8.34 Calculate the SVI of your aeration basin when your 30-minute settleable sample is 360 mL/L and your average mixed liquor suspended solids concentration is 4000 mg/L. Correct Answer: 90 Solution: 360 x 1,000 ------------- = 90 4,000 What is the most widely used dechlorination agent in a conventional chlorine gas plant? Correct Answer: Sulfur Dioxide What is the most prominent concern in failing to remove grit from the wastewater? Correct Answer: Excessive wear and damage on mechanical equipment What is the chemical formula for Sulfuric Acid? Correct Answer: H2SO4 What is the ideal velocity in a grit channel, in feet per second? Correct Answer: 1 fps Conventional pump packing should be: Correct Answer: Tightened down to a drip In a primary clarifier, the expected performance for removing settleable solids is 90-95% removal. What about the removal of suspended solids? Correct Answer: 50% When preparing a sample for laboratory analysis that involves acid and water, how should the sample be poured? Correct Answer: Always pour the acid into the water You are tasked with recording a manual flow sample in an open channel. Where will you position yourself, relative to the weir, to record the most accurate measure of flow? Correct Answer: Behind the weir, 4 times the maximum head of the weir