Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
223 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
Aerobic Bacteria (air-O-bick back-TEER-e-uh)
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
Chapter 2
|
|
|
Algae (AL-jee)
|
Microscopic plants containing chlorophyll that live floating or suspended in water. They also may be attached to structures, rocks, or other submerged surfaces. Excess algal growths can impart tastes and odors to potable water. Algae produce oxygen during sunlight hours and use oxygen during the night hours. Their biological activities appreciably affect the pH, alkalinity, and dissolved oxygen of the water.
|
Chapter 2
|
|
|
Anaerobic Bacteria (AN-air-O-bick back-TEER-e-uh)
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
Chapter
|
|
|
BOD: Biochemical Oxygen Demand.
|
Biochemical Oxygen Demand. The rate at which organisms use the oxygen in water or wastewater while stabilizing decomposable organic matter under aerobic conditions. In decomposition, organic matter serves as food for the bacteria and energy results from its oxidation. BOD measurements are used as a surrogate measure of the organic strength of wastes in water. |
|
|
|
Biochemical Oxygen Demand (BOD) Test
|
A procedure that measures the rate of oxygen use under controlled conditions of time and temperature. Standard test conditions include dark incubation at 20°C for a specified time (usually five days). |
Chapter 2
|
|
|
Coliform (KOAL-i-form)
|
A group of bacteria found in the intestines of warm-blooded animals (including humans) and also in plants, soil, air, and water. The presence of coliform bacteria is an indication that the water is polluted and may contain pathogenic (disease-causing) organisms. Fecal coliforms are those coliforms found in the feces of various warm-blooded animals, whereas the term coliform also includes other environmental sources.
|
Chapter 2
|
|
|
Disinfection
|
The process designed to kill or inactivate most microorganisms in water or wastewater, including essentially all pathogenic (disease-causing) bacteria. There are several ways to disinfect, with chlorination being the most frequently used in water and wastewater treatment plants. Compare with STERILIZATION.
|
Chapter 2
|
|
|
Evapotranspiration (ee-VAP-o-TRANS-purr-A-shun) |
The process by which water vapor is released to the atmosphere by living plants. This process is similar to people sweating. Also called transpiration.
The total water removed from an area by transpiration (plants) and by evaporation from soil, snow, and water surfaces. |
Chapter 2
|
|
|
Imhoff Cone
|
A clear, cone-shaped container marked with graduations. The cone is used to measure the volume of settleable solids in a specific volume (usually one liter) of water or wastewater.
|
Chapter 2
|
|
|
Inorganic Waste
|
Waste material such as sand, salt, iron, calcium, and other mineral materials that are only slightly affected by the action of organisms. Inorganic wastes are chemical substances of mineral origin; whereas organic wastes are chemical substances usually of animal or plant origin. Also see NONVOLATILE MATTER, ORGANIC WASTE, and VOLATILE SOLIDS. |
Chapter 2
|
|
|
Milligrams per Liter (Mg/L)
|
A measure of the concentration by weight of a substance per unit volume in water or wastewater. In reporting the results of water and wastewater analysis, mg/L is preferred to the unit parts per million (ppm), to which it is approximately equivalent. |
Chapter 2
|
|
|
Nutrient Cycle
|
The transformation or change of a nutrient from one form to another until the nutrient has returned to the original form, thus completing the cycle. The cycle may take place under either aerobic or anaerobic conditions. |
Chapter 2
|
|
|
Nutrient
|
Any substance that is assimilated (taken in) by organisms and promotes growth. Nitrogen and phosphorus are nutrients that promote the growth of algae. There are other essential and trace elements that are also considered nutrients. Also see NUTRIENT CYCLE. |
Chapter 2
|
|
|
Nutrient
|
Any substance that is assimilated (taken in) by organisms and promotes growth. Nitrogen and phosphorus are nutrients that promote the growth of algae. There are other essential and trace elements that are also considered nutrients. Also see NUTRIENT CYCLE. |
Chapter 2
|
|
|
Organic Waste
|
Waste material that may come from animal or plant sources. Natural organic wastes generally can be consumed by bacteria and other small organisms. Manufactured or synthetic organic wastes from metal finishing, chemical manufacturing, and petroleum industries may not normally be consumed by bacteria and other organisms. Also see INORGANIC WASTE and VOLATILE SOLIDS.
|
Chapter 2
|
|
|
Pathogenic Organisms
|
Organisms, including bacteria, viruses, protozoa, or internal parasites, capable of causing diseases (such as giardiasis, cryptosporidiosis, typhoid fever, cholera, or infectious hapatitis) in a host (such as a person). (There are many types of organisms that do not cause disease. These organisms are called nonpathogenic.) Also called pathogens.
|
Chapter 2
|
|
|
pH (P H)
|
pH is an expression of the intensity of the basic or acidic condition of a liquid. Mathematically, pH is the logarithm (base 10) of the reciprocal of the hydrogen ion activity.
If {H+} = 10–6.5, then pH = 6.5. The pH may range from 0 to 14, where 0 is most acidic, 14 most basic, and 7 neutral. |
Chapter 2
|
|
|
Pollution
|
The impairment (reduction) of water quality by agricultural, domestic, or industrial wastes (including thermal and radioactive wastes) to a degree that the natural water quality is changed to hinder any beneficial use of the water or render it offensive to the senses of sight, taste, or smell or when sufficient amounts of wastes create or pose a potential threat to human health or the environment.
|
Chapter 2
|
|
|
Primary Treatment
|
A wastewater treatment process that takes place in a rectangular or circular tank and allows those substances in wastewater that readily settle or float to be separated from the wastewater being treated. A septic tank is also considered primary treatment.
|
Chapter 2
|
|
|
pH (P H)
|
pH is an expression of the intensity of the basic or acidic condition of a liquid. Mathematically, pH is the logarithm (base 10) of the reciprocal of the hydrogen ion activity.
If {H+} = 10–6.5, then pH = 6.5. The pH may range from 0 to 14, where 0 is most acidic, 14 most basic, and 7 neutral. |
Chapter 2
|
|
|
Pollution
|
The impairment (reduction) of water quality by agricultural, domestic, or industrial wastes (including thermal and radioactive wastes) to a degree that the natural water quality is changed to hinder any beneficial use of the water or render it offensive to the senses of sight, taste, or smell or when sufficient amounts of wastes create or pose a potential threat to human health or the environment.
|
Chapter 2
|
|
|
Primary Treatment
|
A wastewater treatment process that takes place in a rectangular or circular tank and allows those substances in wastewater that readily settle or float to be separated from the wastewater being treated. A septic tank is also considered primary treatment.
|
Chapter 2
|
|
|
Receiving Water
|
A stream, river, lake, ocean, or other surface or groundwaters into which treated or untreated wastewater is discharged.
|
Chapter 2
|
|
|
pH (P H)
|
pH is an expression of the intensity of the basic or acidic condition of a liquid. Mathematically, pH is the logarithm (base 10) of the reciprocal of the hydrogen ion activity.
If {H+} = 10–6.5, then pH = 6.5. The pH may range from 0 to 14, where 0 is most acidic, 14 most basic, and 7 neutral. |
Chapter 2
|
|
|
Pollution
|
The impairment (reduction) of water quality by agricultural, domestic, or industrial wastes (including thermal and radioactive wastes) to a degree that the natural water quality is changed to hinder any beneficial use of the water or render it offensive to the senses of sight, taste, or smell or when sufficient amounts of wastes create or pose a potential threat to human health or the environment.
|
Chapter 2
|
|
|
Primary Treatment
|
A wastewater treatment process that takes place in a rectangular or circular tank and allows those substances in wastewater that readily settle or float to be separated from the wastewater being treated. A septic tank is also considered primary treatment.
|
Chapter 2
|
|
|
Receiving Water
|
A stream, river, lake, ocean, or other surface or groundwaters into which treated or untreated wastewater is discharged.
|
Chapter 2
|
|
|
Secondary Treatment
|
A wastewater treatment process used to convert dissolved or suspended materials into a form more readily separated from the water being treated. Usually, the process follows primary treatment by sedimentation. The process commonly is a type of biological treatment followed by secondary clarifiers that allow the solids to settle out from the water being treated.
|
Chapter 2
|
|
|
Septic
|
A condition produced by bacteria when all oxygen supplies are depleted. If severe, the bottom deposits produce hydrogen sulfide, the deposits and water turn black, give off foul odors, and the water has a greatly increased oxygen and chlorine demand.
|
Chapter 2
|
|
|
Stabilization
|
Conversion to a form that resists change. Organic material is stabilized by bacteria that convert the material to gases and other relatively inert substances. Stabilized organic material generally will not give off obnoxious odors.
|
Chapter 2
|
|
|
Stabilization
|
Conversion to a form that resists change. Organic material is stabilized by bacteria that convert the material to gases and other relatively inert substances. Stabilized organic material generally will not give off obnoxious odors.
|
Chapter 2
|
|
|
Sterilization
|
The removal or destruction of all microorganisms, including pathogens and other bacteria, vegetative forms, and spores. Compare with DISINFECTION.
|
Chapter 2
|
|
|
Transpiration
|
The process by which water vapor is released to the atmosphere by living plants. This process is similar to people sweating. Also see EVAPOTRANSPIRATION.
|
|
|
|
Biosolids
|
A primarily organic solid product produced by wastewater treatment processes that can be beneficially recycled. The word biosolids is replacing the word sludge when referring to treated waste.
|
|
|
|
Combined Sewer
|
A sewer designed to carry both sanitary wastewaters and stormwater or surface water runoff.
|
|
|
|
Biosolids
|
A primarily organic solid product produced by wastewater treatment processes that can be beneficially recycled. The word biosolids is replacing the word sludge when referring to treated waste.
|
|
|
|
Combined Sewer
|
A sewer designed to carry both sanitary wastewaters and stormwater or surface water runoff.
|
|
|
|
Commution
|
A mechanical treatment process that cuts large pieces of wastes into smaller pieces so they will not plug pipes or damage equipment. Comminution and shredding usually mean the same thing.
|
|
|
|
Detention Time
|
The theoretical (calculated) time required for a given amount of water or wastewater to pass through a tank at a given rate of flow.
The time required to fill a tank at a given flow. The actual time in hours, minutes, or seconds that a small amount of water is in a settling basin, flocculating basin, or rapid-mix chamber. In storage reservoirs, detention time is the length of time entering water will be held before being drafted for use (several weeks to years, several months being typical). |
|
|
|
Dewater
|
To remove or separate a portion of the water present in a sludge or slurry. To dry sludge so it can be handled and disposed of.
To remove or drain the water from a tank or a trench. A structure may be dewatered so that it can be inspected or repaired. |
|
|
|
Detention Time
|
The theoretical (calculated) time required for a given amount of water or wastewater to pass through a tank at a given rate of flow.
The time required to fill a tank at a given flow. The actual time in hours, minutes, or seconds that a small amount of water is in a settling basin, flocculating basin, or rapid-mix chamber. In storage reservoirs, detention time is the length of time entering water will be held before being drafted for use (several weeks to years, several months being typical). |
|
|
|
Dewater
|
To remove or separate a portion of the water present in a sludge or slurry. To dry sludge so it can be handled and disposed of.
To remove or drain the water from a tank or a trench. A structure may be dewatered so that it can be inspected or repaired. |
|
|
|
Facultative Pond
|
The most common type of pond in current use. The upper portion (supernatant) is aerobic, while the bottom layer is anaerobic. Algae supply most of the oxygen to the supernatant.
|
|
|
|
Grit
|
The heavy material present in wastewater such as sand, coffee grounds, eggshells, gravel, and cinders. Also called detritus.
|
|
|
|
Grit
|
The heavy material present in wastewater such as sand, coffee grounds, eggshells, gravel, and cinders. Also called detritus.
|
|
|
|
Headworks
|
The facilities where wastewater enters a wastewater treatment plant. The headworks may consist of bar racks or bar screens, comminutors, a wet well, and pumps.
|
|
|
|
Infiltration
|
The seepage of groundwater into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints and connections, interceptor access risers and covers, or manhole walls.
|
|
|
|
Infiltration
|
The seepage of groundwater into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints and connections, interceptor access risers and covers, or manhole walls.
|
|
|
|
Inflow
|
Water discharged into a sewer system and service connections from such sources as, but not limited to, roof leaders, cellars, yard and area drains, foundation drains, cooling water discharges, drains from springs and swampy areas, around manhole covers or through holes in the covers, cross-connections from storm and combined sewer systems, catch basins, stormwaters, surface runoff, street wash waters, or drainage. Inflow differs from infiltration in that it is a direct discharge into the sewer rather than a leak in the sewer itself. See INTERNAL INFLOW.
|
|
|
|
Infiltration
|
The seepage of groundwater into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints and connections, interceptor access risers and covers, or manhole walls.
|
|
|
|
Inflow
|
Water discharged into a sewer system and service connections from such sources as, but not limited to, roof leaders, cellars, yard and area drains, foundation drains, cooling water discharges, drains from springs and swampy areas, around manhole covers or through holes in the covers, cross-connections from storm and combined sewer systems, catch basins, stormwaters, surface runoff, street wash waters, or drainage. Inflow differs from infiltration in that it is a direct discharge into the sewer rather than a leak in the sewer itself. See INTERNAL INFLOW.
|
|
|
|
Influent
|
Water or other liquid—raw (untreated) or partially treated—flowing INTO a reservoir, basin, treatment process, or treatment plant.
|
|
|
|
Media
|
The material in a trickling filter on which slime accumulates and organisms grow. As settled wastewater trickles over the media, organisms in the slime remove certain types of wastes, thereby partially treating the wastewater. Also, the material in a rotating biological contactor or in a gravity or pressure filter.
|
|
|
|
Photosynthesis
|
A process in which organisms, with the aid of chlorophyll, convert carbon dioxide and inorganic substances into oxygen and additional plant material, using sunlight for energy. All green plants grow by this process.
|
|
|
|
Sanitary Sewer
|
A pipe or conduit (sewer) intended to carry wastewater or waterborne wastes from homes, businesses, and industries to the treatment works. Stormwater runoff or unpolluted water should be collected and transported in a separate system of pipes or conduits (storm sewers) to natural watercourses.
|
|
|
|
Shredding
|
A mechanical treatment process that cuts large pieces of wastes into smaller pieces so they will not plug pipes or damage equipment. Shredding and comminution usually mean the same thing.
|
|
|
|
Sludge
|
The settleable solids separated from liquids during processing.
The deposits of foreign materials on the bottoms of streams or other bodies of water or on the bottoms and edges of wastewater collection lines and appurtenances. |
|
|
|
Storm Sewer
|
A separate pipe, conduit, or open channel (sewer) that carries runoff from storms, surface drainage, and street wash, but does not include domestic and industrial wastes. Storm sewers are often the recipients of hazardous or toxic substances due to the illegal dumping of hazardous wastes or spills caused by accidents involving vehicles transporting these substances. Also see SANITARY SEWER.
|
|
|
|
Storm Sewer
|
A separate pipe, conduit, or open channel (sewer) that carries runoff from storms, surface drainage, and street wash, but does not include domestic and industrial wastes. Storm sewers are often the recipients of hazardous or toxic substances due to the illegal dumping of hazardous wastes or spills caused by accidents involving vehicles transporting these substances. Also see SANITARY SEWER.
|
|
|
|
Supernatant (soo-per-NAY-tent)
|
The relatively clear water layer between the sludge on the bottom and the scum on the surface of a tank or basin, an anaerobic digester, or a septic tank (interceptor). This water from an anaerobic digester is usually returned to the influent wet well or to the primary clarifier. If the water (supernatant) is from a septic tank, it is discharged by gravity or by a pump to a leaching system or a wastewater collection system. Also called clear zone. |
|
|
|
Storm Sewer
|
A separate pipe, conduit, or open channel (sewer) that carries runoff from storms, surface drainage, and street wash, but does not include domestic and industrial wastes. Storm sewers are often the recipients of hazardous or toxic substances due to the illegal dumping of hazardous wastes or spills caused by accidents involving vehicles transporting these substances. Also see SANITARY SEWER.
|
|
|
|
Supernatant (soo-per-NAY-tent)
|
The relatively clear water layer between the sludge on the bottom and the scum on the surface of a tank or basin, an anaerobic digester, or a septic tank (interceptor). This water from an anaerobic digester is usually returned to the influent wet well or to the primary clarifier. If the water (supernatant) is from a septic tank, it is discharged by gravity or by a pump to a leaching system or a wastewater collection system. Also called clear zone. |
|
|
|
Weir
|
A wall or plate placed in an open channel and used to measure the flow of water. The depth of the flow over the weir can be used to calculate the flow rate, or a chart or conversion table may be used to convert depth to flow. Also see PROPORTIONAL WEIR.
A wall or obstruction used to control flow (from settling tanks and clarifiers) to ensure a uniform flow rate and avoid short-circuiting. |
|
|
|
Wet Oxidation
|
A method of treating or conditioning sludge before the water is removed. Compressed air is blown into the liquid sludge. The air and sludge mixture is fed into a pressure vessel where the organic material is stabilized. The stabilized organic material and inert (inorganic) solids are then separated from the pressure vessel effluent by dewatering in lagoons or by mechanical means.
|
|
|
|
Wet Oxidation
|
A method of treating or conditioning sludge before the water is removed. Compressed air is blown into the liquid sludge. The air and sludge mixture is fed into a pressure vessel where the organic material is stabilized. The stabilized organic material and inert (inorganic) solids are then separated from the pressure vessel effluent by dewatering in lagoons or by mechanical means.
|
|
|
|
Wet Well
|
A compartment or tank in which wastewater is collected. The suction pipe of a pump may be connected to the wet well or a submersible pump may be located in the wet well.
|
|
|
|
Aerobic
|
A condition in which atmospheric or dissolved oxygen is present in the aquatic (water) environment.
|
|
|
|
Aerobic
|
A condition in which atmospheric or dissolved oxygen is present in the aquatic (water) environment.
|
|
|
|
Alkalinity
|
The capacity of water or wastewater to neutralize acids. This capacity is caused by the water's content of carbonate, bicarbonate, hydroxide, and occasionally borate, silicate, and phosphate. Alkalinity is expressed in milligrams per liter of equivalent calcium carbonate. Alkalinity is not the same as pH because water does not have to be strongly basic (high pH) to have a high alkalinity. Alkalinity is a measure of how much acid must be added to a liquid to lower the pH to 4.5.
|
|
|
|
Anaerobic Decomposition (AN-air-O-bick)
|
The decay or breaking down of organic material in an environment containing no free or dissolved oxygen. |
|
|
|
Buffer
|
A solution or liquid whose chemical makeup neutralizes acids or bases without a great change in pH
|
|
|
|
Anaerobic Decomposition (AN-air-O-bick)
|
The decay or breaking down of organic material in an environment containing no free or dissolved oxygen. |
|
|
|
Buffer
|
A solution or liquid whose chemical makeup neutralizes acids or bases without a great change in pH
|
|
|
|
Clairifier
|
Settling tank, sedimentation basin. A tank or basin in which wastewater is held for a period of time during which the heavier solids settle to the bottom and the lighter materials float to the water surface.
|
|
|
|
Decomposition or Decay
|
The conversion of chemically unstable materials to more stable forms by chemical or biological action. |
|
|
|
Detritus
|
The heavy material present in wastewater such as sand, coffee grounds, eggshells, gravel, and cinders. Also called grit.
|
|
|
|
Diffuser
|
A device (porous plate, tube, bag) used to break the air stream from the blower system into fine bubbles in an aeration tank or reactor.
|
|
|
|
Digester
|
A tank in which sludge is placed to allow decomposition by microorganisms. Digestion may occur under anaerobic (more common) or aerobic conditions.
|
|
|
|
Digester
|
A tank in which sludge is placed to allow decomposition by microorganisms. Digestion may occur under anaerobic (more common) or aerobic conditions.
|
|
|
|
Dissolved Oxygen
|
Molecular oxygen dissolved in water or wastewater, usually abbreviated DO.
|
|
|
|
Digester
|
A tank in which sludge is placed to allow decomposition by microorganisms. Digestion may occur under anaerobic (more common) or aerobic conditions.
|
|
|
|
Dissolved Oxygen
|
Molecular oxygen dissolved in water or wastewater, usually abbreviated DO.
|
|
|
|
Explosimeter
|
An instrument used to detect explosive atmospheres. When the lower explosive limit (LEL) of an atmosphere is exceeded, an alarm signal on the instrument is activated. Also called a combustible gas detector.
|
|
|
|
Grit Removal
|
Grit removal is accomplished by providing an enlarged channel or chamber that causes the flow velocity to be reduced and allows the heavier grit to settle to the bottom of the channel where it can be removed.
|
|
|
|
Grit Removal
|
Grit removal is accomplished by providing an enlarged channel or chamber that causes the flow velocity to be reduced and allows the heavier grit to settle to the bottom of the channel where it can be removed.
|
|
|
|
Head
|
The vertical distance, height, or energy of water above a reference point. A head of water may be measured in either height (feet or meters) or pressure (pounds per square inch or kilograms per square centimeter). Also see DISCHARGE HEAD, DYNAMIC HEAD, STATIC HEAD, SUCTION HEAD, SUCTION LIFT, and VELOCITY HEAD.
|
|
|
|
Grit Removal
|
Grit removal is accomplished by providing an enlarged channel or chamber that causes the flow velocity to be reduced and allows the heavier grit to settle to the bottom of the channel where it can be removed.
|
|
|
|
Head
|
The vertical distance, height, or energy of water above a reference point. A head of water may be measured in either height (feet or meters) or pressure (pounds per square inch or kilograms per square centimeter). Also see DISCHARGE HEAD, DYNAMIC HEAD, STATIC HEAD, SUCTION HEAD, SUCTION LIFT, and VELOCITY HEAD.
|
|
|
|
Head Loss
|
1) For water: The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. The head loss through a filter is due to friction caused by material building up on the surface or by the water flowing through the filter media. SEE DRAWING.
2) For wastewater: The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. The head loss through a comminutor is due to friction caused by the cutters or shredders as the water passes through them and by the roughness of the comminutor walls conveying the flow through the comminutor. Also called friction loss. SEE DRAWING. |
|
|
|
Grit Removal
|
Grit removal is accomplished by providing an enlarged channel or chamber that causes the flow velocity to be reduced and allows the heavier grit to settle to the bottom of the channel where it can be removed.
|
|
|
|
Head
|
The vertical distance, height, or energy of water above a reference point. A head of water may be measured in either height (feet or meters) or pressure (pounds per square inch or kilograms per square centimeter). Also see DISCHARGE HEAD, DYNAMIC HEAD, STATIC HEAD, SUCTION HEAD, SUCTION LIFT, and VELOCITY HEAD.
|
|
|
|
Head Loss
|
1) For water: The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. The head loss through a filter is due to friction caused by material building up on the surface or by the water flowing through the filter media. SEE DRAWING.
2) For wastewater: The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. The head loss through a comminutor is due to friction caused by the cutters or shredders as the water passes through them and by the roughness of the comminutor walls conveying the flow through the comminutor. Also called friction loss. SEE DRAWING. |
|
|
|
Hydrogen Sulfide Gas (H2S)
|
Hydrogen sulfide is a gas with a rotten egg odor, produced under anaerobic conditions. Hydrogen sulfide gas is particularly dangerous because it dulls the sense of smell, becoming unnoticeable after you have been around it for a while; in high concentrations, it is only noticeable for a very short time before it dulls the sense of smell. The gas is very poisonous to the respiratory system, explosive, flammable, colorless, and heavier than air.
|
|
|
|
Grit Removal
|
Grit removal is accomplished by providing an enlarged channel or chamber that causes the flow velocity to be reduced and allows the heavier grit to settle to the bottom of the channel where it can be removed.
|
|
|
|
Head
|
The vertical distance, height, or energy of water above a reference point. A head of water may be measured in either height (feet or meters) or pressure (pounds per square inch or kilograms per square centimeter). Also see DISCHARGE HEAD, DYNAMIC HEAD, STATIC HEAD, SUCTION HEAD, SUCTION LIFT, and VELOCITY HEAD.
|
|
|
|
Head Loss
|
1) For water: The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. The head loss through a filter is due to friction caused by material building up on the surface or by the water flowing through the filter media. SEE DRAWING.
2) For wastewater: The head, pressure, or energy (they are the same) lost by water flowing in a pipe or channel as a result of turbulence caused by the velocity of the flowing water and the roughness of the pipe, channel walls, or restrictions caused by fittings. Water flowing in a pipe loses head, pressure, or energy as a result of friction. The head loss through a comminutor is due to friction caused by the cutters or shredders as the water passes through them and by the roughness of the comminutor walls conveying the flow through the comminutor. Also called friction loss. SEE DRAWING. |
|
|
|
Hydrogen Sulfide Gas (H2S)
|
Hydrogen sulfide is a gas with a rotten egg odor, produced under anaerobic conditions. Hydrogen sulfide gas is particularly dangerous because it dulls the sense of smell, becoming unnoticeable after you have been around it for a while; in high concentrations, it is only noticeable for a very short time before it dulls the sense of smell. The gas is very poisonous to the respiratory system, explosive, flammable, colorless, and heavier than air.
|
|
|
|
Inorganic Waste
|
Waste material such as sand, salt, iron, calcium, and other mineral materials that are only slightly affected by the action of organisms. Inorganic wastes are chemical substances of mineral origin; whereas organic wastes are chemical substances usually of animal or plant origin. Also see NONVOLATILE MATTER, ORGANIC WASTE, and VOLATILE SOLIDS.
|
|
|
|
Limit Switch
|
A device that regulates or controls the travel distance of a chain or cable.
|
|
|
|
O&M Manual
|
Operation and Maintenance Manual. A manual that describes detailed procedures for operators to follow to operate and maintain a specific treatment plant and the equipment of that plant.
|
|
|
|
Organic Waste
|
Waste material that may come from animal or plant sources. Natural organic wastes generally can be consumed by bacteria and other small organisms. Manufactured or synthetic organic wastes from metal finishing, chemical manufacturing, and petroleum industries may not normally be consumed by bacteria and other organisms. Also see INORGANIC WASTE and VOLATILE SOLIDS.
|
|
|
|
Organic Waste
|
Waste material that may come from animal or plant sources. Natural organic wastes generally can be consumed by bacteria and other small organisms. Manufactured or synthetic organic wastes from metal finishing, chemical manufacturing, and petroleum industries may not normally be consumed by bacteria and other organisms. Also see INORGANIC WASTE and VOLATILE SOLIDS.
|
|
|
|
Ozonation
|
The application of ozone to water, wastewater, or air, generally for the purposes of disinfection or odor control.
|
|
|
|
POTW
|
POTW POTW Publicly Owned Treatment Works. A treatment works that is owned by a state, municipality, city, town, special sewer district, or other publicly owned and financed entity as opposed to a privately (industrial) owned treatment facility. This definition includes any devices and systems used in the storage, treatment, recycling, and reclamation of municipal sewage (wastewater) or industrial wastes of a liquid nature. It also includes sewers, pipes, and other conveyances only if they carry wastewater to a POTW treatment plant. The term also means the municipality (public entity) that has jurisdiction over the indirect discharges to and the discharges from such a treatment works.
|
|
|
|
POTW
|
POTW POTW Publicly Owned Treatment Works. A treatment works that is owned by a state, municipality, city, town, special sewer district, or other publicly owned and financed entity as opposed to a privately (industrial) owned treatment facility. This definition includes any devices and systems used in the storage, treatment, recycling, and reclamation of municipal sewage (wastewater) or industrial wastes of a liquid nature. It also includes sewers, pipes, and other conveyances only if they carry wastewater to a POTW treatment plant. The term also means the municipality (public entity) that has jurisdiction over the indirect discharges to and the discharges from such a treatment works.
|
|
|
|
Pre-Aeration
|
The addition of air at the initial stages of treatment to freshen the wastewater, remove gases, add oxygen, promote flotation of grease, and aid coagulation.
|
|
|
|
Preliminary Treatment
|
A wastewater treatment process that takes place in a rectangular or circular tank and allows those substances in wastewater that readily settle or float to be separated from the wastewater being treated. A septic tank is also considered primary treatment.
|
|
|
|
Preliminary Treatment
|
A wastewater treatment process that takes place in a rectangular or circular tank and allows those substances in wastewater that readily settle or float to be separated from the wastewater being treated. A septic tank is also considered primary treatment.
|
|
|
|
Pretreatment Facility
|
Industrial wastewater treatment plant consisting of one or more treatment devices designed to remove sufficient pollutants from wastewaters to allow an industry to comply with effluent limits established by the US EPA General and Categorical Pretreatment Regulations or locally derived prohibited discharge requirements and local effluent limits. Compliance with effluent limits allows for a legal discharge to a POTW.
|
|
|
|
Putrefaction
|
Biological decomposition of organic matter, with the production of foul-smelling and -tasting products, associated with anaerobic (no oxygen present) conditions.
|
|
|
|
Putrescible
|
Material that will decompose under anaerobic conditions and produce nuisance odors.
|
|
|
|
Putrescible
|
Material that will decompose under anaerobic conditions and produce nuisance odors.
|
|
|
|
Rack
|
Evenly spaced, parallel metal bars or rods located in the influent channel to remove rags, rocks, and cans from wastewater.
|
|
|
|
Raw Wastewater
|
Plant influent or wastewater BEFORE any treatment
|
|
|
|
Screen
|
A device used to retain or remove suspended or floating objects in wastewater. The screen has openings that are generally uniform in size. It retains or removes objects larger than the openings. A screen may consist of bars, rods, wires, gratings, wire mesh, or perforated plates.
|
|
|
|
Shear Pin
|
A straight pin that will fail (break) when a certain load or stress is exceeded. The purpose of the pin is to protect equipment from damage due to excessive loads or stresses.
|
|
|
|
Sludge Digestion
|
The process of changing organic matter in sludge into a gas or a liquid or a more stable solid form. These changes take place as microorganisms feed on sludge in anaerobic (more common) or aerobic digesters.
|
|
|
|
Sludge Digestion
|
The process of changing organic matter in sludge into a gas or a liquid or a more stable solid form. These changes take place as microorganisms feed on sludge in anaerobic (more common) or aerobic digesters.
|
|
|
|
Slurry
|
A watery mixture or suspension of insoluble (not dissolved) matter; a thin, watery mud or any substance resembling it (such as a grit slurry or a lime slurry).
|
|
|
|
Specific Gravity
|
Weight of a particle, substance, or chemical solution in relation to the weight of an equal volume of water. Water has a specific gravity of 1.000 at 4C (39F). Particulates with specific gravity less than 1.0 float to the surface and particulates with specific gravity greater than 1.0 sink. Wastewater particles or substances usually have a specific gravity of 0.5 to 2.5.
Weight of a particular gas in relation to the weight of an equal volume of air at the same temperature and pressure (air has a specific gravity of 1.0). Chlorine gas has a specific gravity of 2.5. |
|
|
|
Activated sludge process
|
A biological wastewater treatment process that speeds up the decomposition of wastes in the wastewater being treated. Activated sludge is added to wastewater and the mixture (mixed liquor) is aerated and agitated. After some time in the aeration tank, the activated sludge is allowed to settle out by sedimentation and is disposed of (wasted) or reused (returned to the aeration tank) as needed. The remaining wastewater then undergoes more treatment.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Coagulants
|
A chemical that causes very fine particles to clump (floc) together into larger particles. This makes it easier to separate the solids from the liquids by settling, skimming, draining, or filtering.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Coagulants
|
A chemical that causes very fine particles to clump (floc) together into larger particles. This makes it easier to separate the solids from the liquids by settling, skimming, draining, or filtering.
|
|
|
|
Colloids
|
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Coagulants
|
A chemical that causes very fine particles to clump (floc) together into larger particles. This makes it easier to separate the solids from the liquids by settling, skimming, draining, or filtering.
|
|
|
|
Colloids
|
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
|
|
|
|
Composite Sample
|
A composite sample is a collection of individual samples obtained at regular intervals, usually every one or two hours during a 24-hour time span. Each individual sample is combined with the others in proportion to the rate of flow when the sample was collected. Equal volume individual samples also may be collected at intervals after a specific volume of flow passes the sampling point or after equal time intervals and still be referred to as a composite sample. The resulting mixture (composite sample) forms a representative sample and is analyzed to determine the average conditions during the sampling period.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Coagulants
|
A chemical that causes very fine particles to clump (floc) together into larger particles. This makes it easier to separate the solids from the liquids by settling, skimming, draining, or filtering.
|
|
|
|
Colloids
|
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
|
|
|
|
Composite Sample
|
A composite sample is a collection of individual samples obtained at regular intervals, usually every one or two hours during a 24-hour time span. Each individual sample is combined with the others in proportion to the rate of flow when the sample was collected. Equal volume individual samples also may be collected at intervals after a specific volume of flow passes the sampling point or after equal time intervals and still be referred to as a composite sample. The resulting mixture (composite sample) forms a representative sample and is analyzed to determine the average conditions during the sampling period.
|
|
|
|
Density
|
A measure of how heavy a substance (solid, liquid, or gas) is for its size. Density is expressed in terms of weight per unit volume, that is, grams per cubic centimeter or pounds per cubic foot. The density of water (at 4°C or 39°F) is 1.0 gram per cubic centimeter or about 62.4 pounds per cubic foot.
|
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Coagulants
|
A chemical that causes very fine particles to clump (floc) together into larger particles. This makes it easier to separate the solids from the liquids by settling, skimming, draining, or filtering.
|
|
|
|
Colloids
|
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
|
|
|
|
Composite Sample
|
A composite sample is a collection of individual samples obtained at regular intervals, usually every one or two hours during a 24-hour time span. Each individual sample is combined with the others in proportion to the rate of flow when the sample was collected. Equal volume individual samples also may be collected at intervals after a specific volume of flow passes the sampling point or after equal time intervals and still be referred to as a composite sample. The resulting mixture (composite sample) forms a representative sample and is analyzed to determine the average conditions during the sampling period.
|
|
|
|
Density
|
A measure of how heavy a substance (solid, liquid, or gas) is for its size. Density is expressed in terms of weight per unit volume, that is, grams per cubic centimeter or pounds per cubic foot. The density of water (at 4°C or 39°F) is 1.0 gram per cubic centimeter or about 62.4 pounds per cubic foot.
|
|
|
|
Detention Time
|
The theoretical (calculated) time required for a given amount of water or wastewater to pass through a tank at a given rate of flow.
The time required to fill a tank at a given flow. The actual time in hours, minutes, or seconds that a small amount of water is in a settling basin, flocculating basin, or rapid-mix chamber. In storage reservoirs, detention time is the length of time entering water will be held before being drafted for use (several weeks to years, several months being typical). |
|
|
|
Aerobic Bacteria
|
Bacteria that will live and reproduce only in an environment containing oxygen that is available for their respiration (breathing), namely atmospheric oxygen or oxygen dissolved in water. Oxygen combined chemically, such as in water molecules (H2O), cannot be used for respiration by aerobic bacteria.
|
|
|
|
Anaerobic Bacteria
|
Bacteria that live and reproduce in an environment containing no free or dissolved oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical compounds that contain oxygen, such as sulfate (SO42–).
|
|
|
|
Bulking
|
Clouds of billowing sludge that occur throughout secondary clarifiers and sludge thickeners when the sludge does not settle properly. In the activated sludge process, bulking is usually caused by filamentous bacteria or bound water.
|
|
|
|
Coagulants
|
A chemical that causes very fine particles to clump (floc) together into larger particles. This makes it easier to separate the solids from the liquids by settling, skimming, draining, or filtering.
|
|
|
|
Colloids
|
Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. When most of the particles in water have a negative electrical charge, they tend to repel each other. This repulsion prevents the particles from clumping together, becoming heavier, and settling out.
|
|
|
|
Composite Sample
|
A composite sample is a collection of individual samples obtained at regular intervals, usually every one or two hours during a 24-hour time span. Each individual sample is combined with the others in proportion to the rate of flow when the sample was collected. Equal volume individual samples also may be collected at intervals after a specific volume of flow passes the sampling point or after equal time intervals and still be referred to as a composite sample. The resulting mixture (composite sample) forms a representative sample and is analyzed to determine the average conditions during the sampling period.
|
|
|
|
Density
|
A measure of how heavy a substance (solid, liquid, or gas) is for its size. Density is expressed in terms of weight per unit volume, that is, grams per cubic centimeter or pounds per cubic foot. The density of water (at 4°C or 39°F) is 1.0 gram per cubic centimeter or about 62.4 pounds per cubic foot.
|
|
|
|
Detention Time
|
The theoretical (calculated) time required for a given amount of water or wastewater to pass through a tank at a given rate of flow.
The time required to fill a tank at a given flow. The actual time in hours, minutes, or seconds that a small amount of water is in a settling basin, flocculating basin, or rapid-mix chamber. In storage reservoirs, detention time is the length of time entering water will be held before being drafted for use (several weeks to years, several months being typical). |
|
|
|
Emulsion
|
A liquid mixture of two or more liquid substances not normally dissolved in one another; one liquid is held in suspension in the other.
|
|
|
|
Flights
|
Scraper boards, made from redwood or other rot-resistant woods or plastic, used to collect and move settled sludge or floating scum.
|
|
|
|
Emulsion
|
A liquid mixture of two or more liquid substances not normally dissolved in one another; one liquid is held in suspension in the other.
|
|
|
|
Effluent
|
Water or other liquid—raw (untreated), partially treated, or completely treated—flowing FROM a reservoir, basin, treatment process, or treatment plant.
|
|
|
|
Flocculation
|
The gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing. This clumping together makes it easier to separate the solids from the water by settling, skimming, draining, or filtering.
|
|
|
|
Flocculation
|
The gathering together of fine particles after coagulation to form larger particles by a process of gentle mixing. This clumping together makes it easier to separate the solids from the water by settling, skimming, draining, or filtering.
|
|
|
|
Freeboard
|
The vertical distance from the normal water surface to the top of the confining wall.
The vertical distance from the sand surface to the underside of a trough in a sand filter. This distance is also called available expansion. |
|
|
|
Gasification
|
Gasification (gas-uh-fuh-KAY-shun)
The conversion of soluble and suspended organic materials into gas during aerobic or anaerobic decomposition. In clarifiers, the resulting gas bubbles can become attached to the settled sludge and cause large clumps of sludge to rise and float on the water surface. In anaerobic sludge digesters, this gas is collected for fuel or disposed of using a waste gas burner. |
|
|
|
Hydraulic Loading
|
Hydraulic Loading
Hydraulic loading refers to the flows (MGD or cu m/day) to a treatment plant or treatment process. Detention times, surface loadings, and weir overflow rates are directly influenced by flows. |
|
|
|
Hydrostatic System
|
Hydrostatic System (hi-dro-STAT-ick)
In a hydrostatic sludge removal system, the surface of the water in the clarifier is higher than the surface of the water in the sludge well or hopper. This difference in pressure head forces sludge from the bottom of the clarifier to flow through pipes to the sludge well or hopper. |
|
|
|
Launders
|
Launders
Sedimentation basin and filter discharge channels consisting of overflow weir plates (in sedimentation basins) and conveying troughs. Sedimentation tank effluent troughs consisting of overflow weir plates. |
|
|
|
Lineal
|
Lineal (LIN-e-ul)
The length in one direction of a line. For example, a board 12 feet (meters) long has 12 lineal feet (meters) in its length. |
|
|
|
Lineal
|
Lineal (LIN-e-ul)
The length in one direction of a line. For example, a board 12 feet (meters) long has 12 lineal feet (meters) in its length. |
|
|
|
MPN
|
MPN
MPN is the Most Probable Number of coliform-group organisms per unit volume of sample water. Expressed as a density or population of organisms per 100 mL of sample water. |
|
|
|
Masking Agents
|
Masking Agents
Substances used to cover up or disguise unpleasant odors. Liquid masking agents are dripped into the wastewater, sprayed into the air, or evaporated (using heat) with the unpleasant fumes or odors and then discharged into the air by blowers to make an undesirable odor less noticeable. |
|
|
|
Millimicron
|
Millimicron (MILL-uh-MY-kron)
A unit of length equal to 10–3µ (one thousandth of a micron), 10–6 millimeters, or 10–9 meters; correctly called a nanometer, nm. |
|
|
|
Molecule
|
Molecule
The smallest division of a compound that still retains or exhibits all the properties of the substance. |
|
|
|
OSHA
|
OSHA (O-shuh)
The Williams-Steiger Occupational Safety and Health Act of 1970 (OSHA) is a federal law designed to protect the health and safety of workers, including the operators of water supply and treatment systems and wastewater collection and treatment systems. The Act regulates the design, construction, operation, and maintenance of water and wastewater systems. OSHA regulations require employers to obtain and make available to workers the Material Safety Data Sheets (MSDSs) for chemicals used at industrial facilities and treatment plants. OSHA also refers to the federal and state agencies that administer the OSHA regulations. |
|
|
|
Package Treatment Plant
|
Package Treatment Plant
A small wastewater treatment plant often fabricated at the manufacturer's factory, hauled to the site, and installed as one facility. The package may be either a small primary or a secondary wastewater treatment plant. |
|
|
|
Package Treatment Plant
|
Package Treatment Plant
A small wastewater treatment plant often fabricated at the manufacturer's factory, hauled to the site, and installed as one facility. The package may be either a small primary or a secondary wastewater treatment plant. |
|
|
|
Representative Sample
|
Representative Sample
A sample portion of material, water, or wastestream that is as nearly identical in content and consistency as possible to that in the larger body being sampled. |
|
|
|
Retention Time
|
Retention Time
The length of time water, sludge, or solids are retained or held in a clarifier or sedimentation tank. Also see DETENTION TIME. |
|
|
|
Rotating Biological Contactor (RBC)
|
Rotating Biological Contactor (RBC)
A secondary biological treatment process for domestic and biodegradable industrial wastes. Biological contactors have a rotating shaft surrounded by plastic discs called the media. The shaft and media are called the drum. A biological slime grows on the media when conditions are suitable and the microorganisms that make up the slime (biomass) stabilize the waste products by using the organic material for growth and reproduction. |
|
|
|
Septicity
|
Septicity (sep-TIS-uh-tee)
The condition in which organic matter decomposes to form foul-smelling products associated with the absence of free oxygen. If severe, the wastewater produces hydrogen sulfide, turns black, gives off foul odors, contains little or no dissolved oxygen, and the wastewater has a high oxygen demand. |
|
|
|
Short-Circuiting
|
Short-Circuiting
A condition that occurs in tanks or basins when some of the flowing water entering a tank or basin flows along a nearly direct pathway from the inlet to the outlet. This is usually undesirable because it may result in shorter contact, reaction, or settling times in comparison with the theoretical (calculated) or presumed detention times. |
|
|
|
Sloughings
|
Sloughings (SLUFF-ings)
Trickling filter slimes that have been washed off the filter media. They are generally quite high in BOD and will lower effluent quality unless removed. |
|
|
|
Sludge Gasification
|
Sludge Gasification
A process in which soluble and suspended organic matter are converted into gas by anaerobic decomposition. The resulting gas bubbles can become attached to the settled sludge and cause large clumps of sludge to rise and float on the water surface. |
|
|
|
Sludge Gasification
|
Sludge Gasification
A process in which soluble and suspended organic matter are converted into gas by anaerobic decomposition. The resulting gas bubbles can become attached to the settled sludge and cause large clumps of sludge to rise and float on the water surface. |
|
|
|
Sludge Volume Index (SVI)
|
Sludge Volume Index (SVI)
A calculation that indicates the tendency of activated sludge solids (aerated solids) to thicken or to become concentrated during the sedimentation/thickening process. SVI is calculated in the following manner: (1) allow a mixed liquor sample from the aeration basin to settle for 30 minutes; (2) determine the suspended solids concentration for a sample of the same mixed liquor; (3) calculate SVI by dividing the measured (or observed) wet volume (mL/L) of the settled sludge by the dry weight concentration of MLSS in grams/L. |
|
|
|
Specific Gravity
|
Specific Gravity
1. Weight of a particle, substance, or chemical solution in relation to the weight of an equal volume of water. Water has a specific gravity of 1.000 at 4C (39F). Particulates with specific gravity less than 1.0 float to the surface and particulates with specific gravity greater than 1.0 sink. 2. Wastewater particles or substances usually have a specific gravity of 0.5 to 2.5. Weight of a particular gas in relation to the weight of an equal volume of air at the same temperature and pressure (air has a specific gravity of 1.0). Chlorine gas has a specific gravity of 2.5. |
|
|
|
Surface Loading
|
Surface Loading
One of the guidelines for the design of settling tanks and clarifiers in treatment plants. Used by operators to determine if tanks and clarifiers are hydraulically (flow) over- or underloaded. Also called overflow rate. Surface Loading One of the guidelines for the design of settling tanks and clarifiers in treatment plants. Used by operators to determine if tanks and clarifiers are hydraulically (flow) over- or underloaded. Also called overflow rate. |
|
|
|
Toxic
|
Toxic
A substance that is poisonous to a living organism. Toxic substances may be classified in terms of their physiological action, such as irritants, asphyxiants, systemic poisons, and anesthetics and narcotics. Irritants are corrosive substances that attack the mucous membrane surfaces of the body. Asphyxiants interfere with breathing. Systemic poisons are hazardous substances that injure or destroy internal organs of the body. Anesthetics and narcotics are hazardous substances that depress the central nervous system and lead to unconsciousness. |
|
|
|
Trickling Filter
|
Trickling Filter
A treatment process in which wastewater trickling over media enables the formation of slimes or biomass, which contain organisms that feed upon and remove wastes from the water being treated. |
|
|
|
Weir Diameter
|
Weir Diameter (weer)
Many circular clarifiers have a circular weir within the outside edge of the clarifier. All the water leaving the clarifier flows over this weir. The diameter of the weir is the length of a line from one edge of a weir to the opposite edge and passing through the center of the circle formed by the weir. |
|
|
|
Aerobic Process
|
Aerobic Process (air-o-bick)
A waste treatment process conducted under aerobic (in the presence of free or dissolved oxygen) conditions. |
|
|
|
Biomass
|
Biomass (BUY-o-mass)
A mass or clump of organic material consisting of living organisms feeding on the wastes in wastewater, dead organisms, and other debris. Also see ZOOGLEAL FILM and ZOOGLEAL MASS. |
|
|
|
Distributor
|
Distributor
The rotating mechanism that distributes the wastewater evenly over the surface of a trickling filter or other process unit. Also see FIXED-SPRAY NOZZLE. |
|
|
|
Distributor
|
Distributor
The rotating mechanism that distributes the wastewater evenly over the surface of a trickling filter or other process unit. Also see FIXED-SPRAY NOZZLE. |
|
|
|
Fixed Spray Nozel
|
Fixed-Spray Nozzle
Cone-shaped spray nozzle used to distribute wastewater over the filter media, similar to a lawn sprinkling system. A deflector or steel ball is mounted within the cone to spread the flow of wastewater through the cone, thus causing a spraying action. Also see DISTRIBUTOR. |
|
|
|
Force Main
|
Force Main
A pipe that carries wastewater under pressure from the discharge side of a pump to a point of gravity flow downstream. |
|
|
|
Force Main
|
Force Main
A pipe that carries wastewater under pressure from the discharge side of a pump to a point of gravity flow downstream. |
|
|
|
Humus Sludge
|
Humus Sludge
The sloughed particles of biomass from trickling filter media that are removed from the water being treated in secondary clarifiers. |
|
|
|
Loading
|
Loading
Quantity of material applied to a device at one time. |
|
|
|
Microrganisms
|
Microorganisms (MY-crow-OR-gan-is-ums)
Living organisms that can be seen individually only with the aid of a microscope. |
|
|
|
Nitrification
|
Nitrification (NYE-truh-fuh-KAY-shun)
An aerobic process in which bacteria change the ammonia and organic nitrogen in water or wastewater into oxidized nitrogen (usually nitrate). |
|
|
|
Orifice
|
Orifice (OR-uh-fiss)
An opening (hole) in a plate, wall, or partition. An orifice flange or plate placed in a pipe consists of a slot or a calibrated circular hole smaller than the pipe diameter. The difference in pressure in the pipe above and at the orifice may be used to determine the flow in the pipe. In a trickling filter distributor, the wastewater passes through an orifice to the surface of the filter media. |
|
|
|
Orifice
|
Orifice (OR-uh-fiss)
An opening (hole) in a plate, wall, or partition. An orifice flange or plate placed in a pipe consists of a slot or a calibrated circular hole smaller than the pipe diameter. The difference in pressure in the pipe above and at the orifice may be used to determine the flow in the pipe. In a trickling filter distributor, the wastewater passes through an orifice to the surface of the filter media. |
|
|
|
Parallel Operation
|
Parallel Operation
Wastewater being treated is split and a portion flows to one treatment unit while the remainder flows to another similar treatment unit. Also see SERIES OPERATION. |
|
|
|
Physical Waste Treatment Process
|
Physical Waste Treatment Process
Physical wastewater treatment processes include use of racks, screens, comminutors, clarifiers (sedimentation and flotation), and filtration. Chemical or biological reactions are important treatment processes, but not part of a physical treatment process. |
|
|
|
Protozoa
|
Protozoa (pro-toe-ZOE-ah)
A group of motile, microscopic organisms (usually single-celled and aerobic) that sometimes cluster into colonies and generally consume bacteria as an energy source. |
|
|
|
Recirculation
|
Recirculation
The return of part of the effluent from a treatment process to the incoming flow. |
|
|
|
Series Operation
|
Series Operation
Wastewater being treated flows through one treatment unit and then flows through another similar treatment unit. Also see PARALLEL OPERATION. |
|
|
|
Series Operation
|
Series Operation
Wastewater being treated flows through one treatment unit and then flows through another similar treatment unit. Also see PARALLEL OPERATION. |
|
|
|
Shock Load
|
Shock Load
The arrival at a water treatment plant of raw water containing unusual amounts of algae, colloidal matter, color, suspended solids, turbidity, or other pollutants. The arrival at a waste treatment facility of a waste that is toxic to organisms in sufficient quantity or strength to cause operating problems. Possible problems include odors and sloughing off of the growth or slime on trickling filter media, or bulking sludge, which will result in a high loss of solids from the secondary clarifiers into the plant effluent and a biological process upset. Organic or hydraulic overloads also can cause a shock load. |
|
|
|
Trickling Filter
|
Trickling Filter
A treatment process in which wastewater trickling over media enables the formation of slimes or biomass, which contain organisms that feed upon and remove wastes from the water being treated. |
|
|
|
Trickling Filter Media
|
Trickling Filter Media
Rocks or other durable materials that make up the body of the filter. Synthetic (manufactured) media have also been used successfully. |
|
|
|
Two-Stage Filters
|
Two-Stage Filters
Two filters are used. Effluent from the first filter goes to the second filter, either directly or after passing through a clarifier. |
|
|
|
Zoogleal Film
|
Zoogleal Film (ZOE-uh-glee-ul)
A complex population of organisms that form a slime growth on the trickling filter media and break down the organic matter in wastewater. These slimes consist of living organisms feeding on the wastes in wastewater, dead organisms, silt, and other debris. Slime growth is a more common term. |
|
