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GLOSSARY

Glossary

Greenwave BioService

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ACTIVATED SLUDGE PROCESS:

Federal/State National Pollutant Discharge Elimination System.

GLOSSARY

A biological wastewater treatment process which speeds up the decomposition of organic 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.

ACTIVATED SLUDGE:

Sludge particles produced in raw or settled wastewater (primary effluent) by the growth of organisms (including Zoogleal bacteria) in aeration tanks in the presence of dissolved oxygen. The term "activated" comes from the fact that the particles are teeming with bacteria, fungi, and protozoa. Activated sludge is different from primary sludge in that the sludge particles contain many living organisms which can feed in the incoming wastewater.

ACID:

(1) A substance that tends to lose a proton.

(2)A substance that dissolves in water with the formation of a hydrogen ion.

(3)A substance containing hydrogen which may be replaced by metals to form salts.

(4) A substance that is corrosive.

AERATION:

The process of adding air. In wastewater treatment, air is added to freshen wastewater and to keep solids in suspension. With mixtures of wastewater and activated sludge, adding air provides mixing and oxygen for microorganisms treating the wastewater.

ALGAE:

Microscopic plants which contain chlorophyll and float or are suspended in water. They also may be attached to structures, rocks, or other similar substances.

ALKALI:

Any of certain soluble salts, principally of sodium, potassium, magnesium, and calcium, that have the property of combining with acids to form neutral salts and may be used in chemical processes such as water or wastewater treatment.

AEROBIC BACTERIA:

Bacteria which will live and reproduce only in an environment with oxygen which is available for their respiration, 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" oxygen. Anaerobic bacteria obtain their oxygen supply by breaking down chemical oxygen compounds which contain oxygen, such as sulfates (SO-4).

BOD:

Biochemical Oxygen Demand

The rate at which microorganisms use the oxygen in water or wastewater while stabilizing decomposable matter under aerobic conditions. In decomposition, organic matter serves as food for the bacteria and energy results from its oxidation.

BIOMASS:

A mass or clump of living organisms feeding on the wastewater, dead organisms, and other debris. This mass may be formed for function or as protection against predators and storage of food supplies.

BTEX:

A measurement of organic pollutants used in the refining of gasoline and higher refinery products. These are additives used in the "cracking" or refining of higher volatility products (some solvents, for example) from an oil refinery. Water may not be discharged to surface under permits if BTEX exceeds 5 parts per billion.

CHEMICAL OXYGEN DEMAND: (COD)

A measure of the oxygen-consuming capacity of organic matter present in wastewater. COD is expressed as the amount of oxygen consumed from a chemical oxidant in mg/l during a specific test. Results are not necessarily related to the BOD because the chemical oxidant may react with substances that bacteria do not stabilize.

CHLORINATION:

The application of chlorine to water or wastewater, generally for the purpose of disinfection, but frequently for accomplishing other biological or chemical results.

COLIFORM:

One of the bacteria. The presence of coliform-group bacteria is an indication of possible pathogenic bacteria contamination. The human intestinal tract is one of the main habitats of coliform bacteria. They may also be found in the intestinal tracts of warm-blooded animals, and plants, soil, air, and the aquatic environment. Fecal Coliforms are those coliforms found in the feces of various warm-blooded animals; whereas the term "coliform" also includes other environmental sources.

COLLECTION SYSTEM:

Comprised of the sanitary sewer lines, lift stations, which are utilized to move the waste stream from the point of entry to the waste treatment facility.

COMBINED SEWER:

A sewer designed to carry both sanitary wastewaters and storm-or surface-waters runoff.

CONVENTIONAL TREATMENT:

The pre-treatment, sedimentation, floatation, trickling filter, activated sludge, and chlorination wastewater treatment processes.

CONTACT CHAMBER:

An area, usually a large open box, where chlorine is introduced to the plant effluent immediately prior to discharge into surface waters. This is for disinfection purposes, and is the final treatment to knock out pollutants. Sometimes, the plant is so inefficient that more chlorine is needed than can be discharge, this in turn requires additional treatment by de-chlorinization.

CONTACT STABILIZATION:

A modification of activated sludge treatment. Two aeration tanks are used, one for separate re-aeration of return sludge for at least four hours before being returned into the second tank for mixing with the primary influent (raw sewage) needing treatment.

DECHLORINIZATION:

The removal of chlorine from the effluent of a treatment plant.

DENITRIFICATION:

An anaerobic process that occurs when nitrites or nitrate ions are reduced (have hydrogen added) to nitrogen gas and bubbles are a result. The bubbles are attached to the biological flocs (clumps) and float to the surface. This is often the cause of rising sludge or sludge caps in secondary clarifiers.

DETENTION TIME:

The time required to fill a tank at a given flow or theoretical time required for a given flow of wastewater to pass through a tank.

DIGESTER:

A tank in which sludge is placed to allow decomposition by micro-organisms. Digestion may occur under anaerobic (more common) or aerobic conditions.

DISINFECTION:

The process designed to kill most micro-organisms in wastewater, including essentially all pathogenic (disease-causing) bacteria. There are several ways to disinfect, with chlorine being most frequently used in water and wastewater treatment plants.

D.O.:

Dissolved Oxygen is the molecular (atmospheric) oxygen dissolved in water or wastewater.

EFFLUENT:

Wastewater or other liquid - raw, partially, or completely treated - flowing FROM a basin, treatment process, or treatment plant.

ENZYMES:

Enzymes are organic substances which are produced by living organisms and speed up chemical changes.

FACULATATIVE:

Faculatative bacteria can use either molecular (dissolved) oxygen or oxygen obtained from food materials such as sulfate or nitrate ions. In other words, faculatative bacteria can live under aerobic or anaerobic conditions.

FORCE MAIN:

A pipe that conveys wastewater under pressure from the discharge side of a pump to a point of gravity flow.

FLOCCULATION:

The gathering together of fine particles to produce larger particles. In many plants, organic chemicals are used to speed up this process. Negatively and positively charged chemicals (cationic and anionic) are used to bind the soluble or lighter particles, and sludge formation is thus enhanced.

IMPELLER PUMPS:

Any pumps in which the water is moved by the continuos application of power to a rotating set of vanes from some mechanical source.

INFILTRATION:

The seepage of ground water into a sewer system, including service connections. Seepage frequently occurs through defective or cracked pipes, pipe joints, connections, or manhole walls.

INORGANIC / ORGANIC WASTES:

Inorganic wastes are chemical substances of a mineral origin - sand, dirt, iron, calcium, etc. - and are little or un-affected by biological degradation processes. Organic wastes come from animal or vegetable origins. As an aside, most plastics are considered organic, since their base stocks are petroleum hydrocarbons. But they are so altered that they are generally not biodegradable, and are thus inorganic in actual practice.

LIFT STATION (WET WELL):

A chamber of varying size which is built to artificially induce gravity for a wastewater flow. Typically, the chamber consists of an inlet, a pumping device, one or more floats to turn the pumps on and off, and an outlet. It may be likened to locks in a canal in function.

MERCAPTANS:

Compounds containing sulfur which have an extremely offensive skunk odor.

MATERIAL SAFETY DATA SHEETS (MSDS):

A form required by the government which lists the ingredients of a product, with special emphasis on hazardous materials, and how to treat human exposure and spillage. MSDS's were required for all materials with hazardous item, but as a CYA, most facilities will require an MSDS for every compound used or stored on their premises.

Federal/State NPDES PERMIT:

Federal/State National Pollutant Discharge Elimination System.

This permit is the regulatory agency document issued by either a federal or state agency which is designed to control all discharges of pollutants from point sources into the U.S. waterways. NPDES permits regulate discharges into navigable, receiving and ground waters from all point sources of pollution, including pretreatment and primary treatment in industries, municipal treatment plants, and large agricultural feed lots and return irrigation flows.

NUTRIENTS:

Substances which are required to support living plants and organisms. Major nutrients are carbon, hydrogen, sulfur, nitrogen, and phosphorous. Nitrogen and phosphorous are difficult to remove from wastewater by conventional treatment processes because they are water soluble and tend to recycle.

NITRIFICATION:

When bacteria change the ammonia and organic nitrogen in wastewater into oxidized nitrogen (nitrate).

O & G ( OIL & GREASE OR FOG - FATS, OIL, & GREASE):

A measurement of both hydrophobic (free-floating) and emulsified (chemically dispersed) oils and greases present in a substrate. This test will show that O&G are present when chemical degreasers are added, despite a visual appearance to the contrary.

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 secondary wastewater treatment plant.

PATHOGENIC ORGANISMS:

Bacteria, viruses, or cysts which can cause disease (typhoid, cholera, dysentery). There are many types of bacteria which do NOT cause disease and which are NOT called pathogenic. Many beneficial bacteria are found in wastewater treatment processes actively cleaning up organic wastes.

pH:

pH is an expression of the intensity of the basic or acid condition of a liquid. The pH may range from 0 - 14, where 0 is most acid, 14 the most basic, and 7 is neutral. Natural waters usually have a pH of between 6.5 & 8.5.

POLLUTION:

Any change in the natural state of water which interferes with its beneficial reuse or causes failure to meet water quality requirements.

PRETREATMENT FACILITY:

Industrial wastewater treatment plant consisting of one or more treatment devices designed to remove sufficient pollutants from the wastewater 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 the effluent limits allows for a legal discharge to POTW (Publicly Owned Treatment Works).

RECIRCULATION:

The reintroduction of a certain portion of treated wastewater back into various points at or near the plant headworks.

REDUCTION:

Chemically, the addition of hydrogen or removal of oxygen or the addition of electron to an element or compound. The production of Hydrogen Sulfide (H2S) under anaerobic conditions is caused by the reduction of sulfate compounds of elemental sulfur.

SEPTIC:

This condition is produced by anaerobic bacteria. If severe, the wastewater turns black, gives off foul odors, contains little or no oxygen, and creates a heavy oxygen demand.

SHOCK LOAD:

The arrival at a plant of a waste which 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 the trickling filter media. Organic or hydraulic overloads may also cause a shock load.

SUBSTRATE:

The typical components of a given wastewater streams. In usage, the "substrate" of a municipal sewer system will differ from that of a pulp paper plant, due to vastly different pollutants.

SUPERNATANT:

Liquid removed from settled sludge. Supernatant commonly refers to the liquid between the sludge on the bottom and the scum on the surface of an anaerobic digester. This liquid isusually returned to the influent wet well or primary clarifier.

SANITARY SEWER:

A sewer intended to carry wastewater from homes, businesses, and industries. Storm water runoff should be collected and transported in a separate system of pipes.

SUSPENDED SOLIDS:

(1) Solids that either float on the surface of, or are in suspension in, water, wastewater, or other liquids, and which are largely removable by laboratory filtering. (2) The quantity of material removed from wastewater in a laboratory test as prescribed in Standard Methods, and referenced as Total Suspended Solids Dried at 103 - 105 degrees C.

TOTAL RESIDUAL CHLORINE:

The amount of chlorine remaining after a given contact time. The sum of the combined available residual chlorine and the free available residual chlorine.

TRICKLING FILTER:

A treatment process in which the wastewater trickles over media that provide the opportunity for the formation of slimes or biomass which contain organisms that feed upon and remove wastes from the water treated.

TPH ( TOTAL PETROLEUM HYDROCARBONS ):

Generally, a measurement of the pollution level of a substrate by petroleum products less refined than gasoline products. This measurement is usually a reflection of lubricating oil and diesel fuel contamination.

VOC ( VOLATILE ORGANIC COMPOUNDS ):

The BTEX family are in this broad category of 106 substances defined as hazardous by the EPA. In determining wastewater permit compliance, total VOCs may not exceed 2.1 mg/l, though other specifics may carry much lower numbers.

WASTEWATER:

The used water and solids from a community that flows to a treatment plant. Storm water, surface water, and ground water, infiltration may also be included in the wastewater that enters a plant. The term "sewage" usually refers to household wastes, but this word in being replaced by the term "wastewater".