MacConkey Streak: Laboratory test for the presence of gram negative bacteria
We use this test to detect contamination of Bacillus products such as CF 1000, 1002, 4002 and som of the Enz-Odor® products.
Macronutrient: An element required in large proportion by plants and other life forms for survival and growth. Macronutrients include Nitrogen (N), Potassium (K), and Phosphorous (P).
Market grade (wirecloth): Screens that meet general industrial specifications and have a low percentage of open area.
Masking agent: Substance used to cover up or disguise unpleasant odors. Liquid masking agents are dripped into 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.
M: Microorganisms - small organisms which require a microscope to be seen. M
represents the SS in the mixed liquor and is part of the F/M ratio.
MCRT: Mean Cell Retention Time - days. An expression of the average time that a microorganism will spend in an activated sludge process.
Mean filtration rating: Derived from Bubble Point test method. This data should be used as a guide only to compare overall retention capabilities between fabrics and should not be considered a guarantee of the particle size that the fabric will retain.
Mechanical aeration: The use of machinery to mix air and water so that oxygen can be absorbed into the water. Some examples are paddle wheels, mixers, rotating brushes to agitate the surface of an aeration tank; pumps to create fountains; and pumps to discharge water down a series of steps forming falls or cascades. Media: The material in the 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 (RBC) or in a gravity or pressure filter.
MEK: Methyl ethyl ketone.
Membrane: A thin polymeric film with pores.
Mercaptans: Compounds containing sulfur which have an extremely offensive skunk-like odor. Also sometimes described as smelling like garlic or onions. Mesh count: The number of threads in a linear inch of fabric/wire cloth. Mesh opening: See Pore size.
Mesophilic bacteria: A group of bacteria that grow and thrive in a moderate temperature range between 68 F (20 C) and 113 F (45 C). Metabolism: All of the processes or chemical changes in an organism or a single cell by which food is built up (anabolism) into living protoplasm and by which protoplasm is broken down (catabolism) into simpler compounds with the exchange of energy.
Metalized screens: Screens that have been metalized with nickel. These screens will bleed off static charges, promote EMC and reflect electromagnetic energy. MGD: Million gallons daily - refers to the flow through a waste treatment plant.
Mg/L: Milligrams per liter = ppm (parts per million) - expresses a measure of the concentration by weight of a substance per unit volume. Micron: A unit of length. One millionth of a meter or one thousandth of a millimeter. One micron equals 0.00004 of an inch.
Micronutrient: An element required by plants and bacteria, in proportionately smaller amounts, for survival and growth. Micronutrients include: Iron (Fe), Managanese (MN), Zinc (Zn), Boron (B), and Molybdenum (Mo). MIK: Methyl Isobutyl Ketone.
Mill grade (wire cloth): Stainless steel screens that have moderate open area and good strength.
Molecule: The smallest division of a compound that still retains or exhibits all the properties of the substance.
Monoculture: Aquaculture in which one species is grown.
Motile: Motile organisms exhibit or are capable of movement.
ML: Mixed Liquor - the combination of raw influent and returned activated sludge.
(no, not mixed drinks for human consumption)
MLSS: Mixed Liquor Suspended Solids - the volume of suspended solids (see SS) in the mixed liquor (see ML) of an aeration tank.
MLVSS: Mixed Liquor Volatile Suspended Solids - the volume of organic solids that can evaporate at relatively low temperatures (550 C) from the mixed liquor of an aeration tank. This volatile portion is used as a measure or indication of microorganisms present. Volatile substances can also be partially removed by air stripping.
MPN index: 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.
MSDS: Material Safety Data Sheet - a document that provides pertinent information and a profile of a particular hazardous substance or mixture. An MSDS is normally developed by the manufacturer or formulator of the hazardous substance or mixture. The MSDS is required to be made available to employees and operators whenever there is the likelihood of the hazardous substance or mixture being introduced into the workplace. Some manufacturers prepare MSDS for products that are not considered to be hazardous to show that the product or substance is not hazardous.
Mutualism: Two species living together in a relationship in which both benefit from the association.
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