1. What should be your most important concern after a chemical spill? a. aquatic life b. clean-up procedures c. health-related effects d. odors 2. A sewer-use ordinance should specify the personnel performing _. a. cleaning of the main lines b. monitoring c. repairing of broken pipes d. sealing of leaky joints 3. What factor must…
1. What is the normal detention time in the conventional activated sludge aeration tank? a. 2 to 4 hours b. 4 to 8 hours c. 18 to 30 hours 2. An SVI below 75 usually indicates _. a. young sludge b. old sludge c. normal conditions 3. Which of the following is not used to…
1. What is the loading rate in gpm/sq ft if a flow of 1,000,000 gal/day flows into a clarifier measuring 20 ft by 25 ft? Loading rate, gpm/sq ft = (GPM / Area, sqft) 2. What is the flow through a trickling filter in gpm if flow = 135 cu ft/min? 3. What is the…
SLUDGE RE-USE AND DISPOSAL Because sludge consists of nutrients, organic molecules and trace metals that are needed by plants for growth, it makes an excellent soil conditioner. In fact, in countries such as China, various forms of sludge have been used as a soil conditioner for thousands of years. The general public often expresses concern…
Vacuum Sewer Systems (cont) Calculate Flow Rates A 2 feet wide rectangular channel is flowing 30 inches deep with an average velocity of 0.8 feet per second. What is the approximate flow rate? To find the flow rate use a variation of the velocity equation. First calculate the area of the channel, and we have…
Instructions for Submitting Reports to IDEM’s Office of Water Quality The Compliance Branch of IDEM’s Office of Water Quality (OWQ) routinely receives reports at two email addresses: wwReports@idem.IN.gov and wwViolationResponse@idem.IN.gov Emails with blank or vague subject lines significantly delay OWQ’s processing time. Please help OWQ work efficiently by typing your email subject line as shown…
Vacuum Sewer Systems (cont) Operation and Maintenance Vacuum stations function as transfer facilities between a central collection point for all vacuum sewer lines and a pressurized line leading directly or indirectly to a treatment facility. Vacuum pumps are needed to produce the vacuum necessary for liquid/air transport. They may be either the liquid-ring or sliding-vane…
Sludge Drying Beds The use of sludge drying beds is usually limited to small to medium sized (< 5.0 MGD) plants due to land and manpower requirements. In the southern states, the abundance of warm weather, sunshine, wind and land makes drying beds a good sludge drying process for many treatment plants. In the northern…
Centrifuge Centrifugal thickening of wastewater sludge is accomplished by subjecting the sludge to high centrifugal forces. Sludge is fed into a rotating bowl. Solids separation occurs due to centrifugal force impelling the solids to the bowl wall where they are compacted. The liquid and fine solids (centrate) exit the unit through the effluent line. Thickened…
Vacuum Sewer Systems (cont) The advantage of vacuum collection systems may include substantial reductions in water use, material costs, excavation costs, and treatment expenses. In short, there is a potential for overall cost effectiveness. Specifically, the following advantages are evident: • Small pipe sizes, usually 4”, 6”, 8” and 10” are used. • No manholes…
