How Anaerobic Digestion Works Anaerobic digestion relies upon the actions of two groups of bacteria living together in the same environment. One group consists of SAPROPHYTIC organisms, commonly referred to as the “acid formers”. The second group, which uses the acid produced by the saprophytes, is the “methane fermenters”. The methane fermenters are not as…
COMMON OPERATIONAL PROBLEMS The operator should check all pumps and motors every day to insure proper operation. After spending a certain amount of time with these pumps and motors an operator should be able to tell just by listening to them whether they are working properly. The vast majority of pumping problems are either a…
1. After a collection system problem has been solved, you should _. a. wait until tomorrow to fill out the report forms b. take a break c. go home d. evaluate the effectiveness of the results 2. Why must you always know where a cleaning tool is in a sewer? a. so the tool can…
1. The machine that tears debris after the bar screen is called a _. a. barometer b. concubine c. comminutor d. blender 2. The principle function of the zoogleal mass on the trickling filter is to _. a. filter the suspended solids b. reduce the organic content c. reduce the nitrogenous BOD d. control the…
Rearranging a Formula Sometimes the way a formula is written, the item you are trying to find does not stand alone. You must rearrange or transpose the formula to solve for the unknown. When rearranging a formulas, think of a formula as a balanced scale – the quantity on the left has to equal the…
LUBRICATION Pumps, motors, and drives should be oiled and greased in strict accordance with the recommendations of the manufacturer. PUMP CHARACTERISTIC CURVES Every pump has certain characteristics under which it will operate efficiently. These conditions can be illustrated with pump characteristic curves. The graph of the pump curve should show: 1. The head capacity curve…
SOLIDS HANDLING PROCESSES When a wastewater treatment plant is operating properly, most of the solids in the wastewater will be removed at the plant while the water itself will be discharged as effluent to the receiving waters. These solids, known as sludge, must be stabilized and reduced in volume before they can be reused or…
Slope Sewer pipes must be adequately sloped to reduce solids deposition and production of hydrogen sulfide and methane. Table 4-2 presents a list of minimum slopes for various pipe sizes. If a sewer slope of less than the recommended value must be provided, the responsible review agencies may require depth and velocity computations at minimum,…
Design Flow Sanitary sewers are designed to carry peak residential, commercial, institutional, and industrial flows, as well as infiltration and inflow. Gravity sewers are designed to flow full at the design peak flow. Design flows are based on various types of developments. If it is assumed that the average velocity of the wastewater in the…
Changes in Sampling Program Data on system performance can be greatly affected by changes in a sampling program. If improper sampling locations or laboratory procedures are used, lab results could vary considerably. When the lab data varies widely from one day to the next, check sampling location, time, and lab procedures for errors. Remember that…
