Package Plants

 A package treatment plant is a method of sewage treatment which uses a process involving energy and mechanical, biological, chemical or physical treatment of the wastewater to reduce Biological Oxygen Demand (BOD), suspended solids (SS), nitrogen (N), bacteria and other sewage constituents and which is of a degree of complexity that a certified wastewater treatment plant operator is required.


Packed Bed Scrubber

 Packed Bed Scrubber is a wet scrubber that removes acids, soluble gasses, chemicals, fumes, and odors. Contaminated gas flows through a specially designed packing media that is wetted with recirculated liquid. The liquid solvent absorbs the gas pollutant by physical or chemical means.

Packed Tower

 A pollution control device that forces dirty air through a tower packed with crushed rock or wood chips while liquid is sprayed over the packing material. The pollutants in the air stream either dissolve or chemically react with the liquid. 

Palatable Water

 Water, at a desirable temperature, that is free from objectionable tastes, odors, colors, and turbidity.

Palmer Drought Severity Index

 The Palmer drought index is based on a supply-and-demand model of soil moisture. Supply is comparatively straightforward to calculate, but demand is more complicated, as it depends on many factors: not just temperature and the amount of moisture in the soil but also hard-to-calibrate factors including evapotranspiration and recharge rates. Palmer tried to overcome such difficulties by developing an algorithm that approximated them based on the most readily available data, precipitation and temperature.

The index has been most effective in determining long-term drought, a matter of several months, but it is not as good with conditions over a matter of weeks. The Palmer index can, therefore, be applied to any site for which sufficient precipitation and temperature data is available.

Palustrine Aquatic Beds

 Inland areas which contain floating or submerged aquatic vegetation. 

Palustrine Emergents

 Plants growing in inland marshes and wet meadows.


Palustrine Forested

Inland areas such as forested swamps or bogs.

Palustrine Shrub

 Inland wetland area with shrub growth. 

Particulate matter

 (Similar term(s): PM, suspended particulate matter, total suspended particulates, black smoke, inhalable particles, thoracic particles, Respirable particles): It may be defined as the sum of all microscopic solid and liquid particles, of human and natural origin, that remain suspended in a medium such as air for some time. These particles vary greatly in size, composition, and origin, and may be harmful. Particulate matter may be in the form of fly ash, soot, dust, fog, fumes etc

Potable Water

 Drinking water, also known as potable water or improved drinking water, is water safe enough for drinking and food preparation.