Vadose zone: Unsaturated zone of soil above the groundwater, extending from the bottom of the capillary fringe all the way to the soil surface. Vector: (i) Plasmid or virus used in genetic engineering to insert genes into a cell, (ii) Agent, usually an insect or other animal, able to carry pathogens from one host to another.

Vegetative: Actually growing state.

Vegetative cell: Growing or feeding form of a microbial cell, as opposed to a resting form such as a spore.

Vesicles: Spherical structures, formed intracellularly, by some arbuscular mycorrhizal fungi.

Viable: Alive; able to reproduce.

Viable but nonculturable: Organisms that are alive but cannot be cultured on laboratory media.

Viable count: Measurement of the concentration of live cells in a microbial population.

Vibrio: (i) Curved, rod-shaped bacterial cell, (ii) Bacterium of the genus Vibrio. Virion: Virus particle; the virus nucleic acid surrounded by protein coat and in some cases other material. Virulence: Degree of pathogenicity of a parasite.

Virus: Any of a large group of submicroscopic infective agents that typically contain a protein coat surrounding a nucleic acid core and are capable of growth only in a living cell.

Volatile: A volatile substance is one that is capable of being evaporated or changed to a vapor at a relatively low temperature. Volatile substances also can be partially removed by air stripping.

Volume resistivity: Or specific resistivity of a material, expressed in W/cm. Resistance to electrical current flow through the bulk of an object. VS/L: Measure of volatile solids, usually expressed as g VS/L/day-grams volatile solids per liter per day.

WAS: Waste activated sludge, mg/L. The excess growth of microorganisms which must be removed from the process to keep the biological system in balance. Wastewater: The used water and solids from a community that flow to a treatment plant. Storm water, surface water, and groundwater infiltration also may be included in the wastewater that enters a wastewater treatment plant. The term "sewage" usually refers to household wastes, but this word is being replaced by the term "wastewater".

Water content: Water contained in a material expressed as the mass of water per unit mass of oven-dry material.

Water-retention curve: Graph showing soil-water content as a function of increasingly negative soil water potential.

Weathering: All physical and chemical changes produced in rock by atmospheric agents.

Weir: A wall or plate placed in an open channel and used to measure the flow of water.

White rot fungus: Fungus that attacks lignin, along with cellulose, and hemicellulose, leading to a marked lightening of the infected wood. Wild type: Strain of microorganism isolated from nature. The usual or native form of a gene or organism.

Winogradsky column: Glass column with an anaerobic lower zone and an aerobic upper zone, which allows growth of microorganisms under conditions similar to those found in nutrient-rich water and sediment.

Woronin body: Spherical structure associated with the simple pore in the septa separating hyphal compartments of fungi in the phylum Ascomycota.

Waste Management And Control

Waste Management And Control

Get All The Support And Guidance You Need To Be A Success At Understanding Waste Management. This Book Is One Of The Most Valuable Resources In The World When It Comes To The Truth about Environment, Waste and Landfills.

Get My Free Ebook

Post a comment