Population equivalent


Population equivalent '' or unit per capita loading, or equivalent person , is a parameter for characterizing industrial wastewaters. It essentially compares the polluting potential of an industry with a population, which would produce the same polluting load. In other words, it is the number expressing the ratio of the sum of the pollution load produced during 24 hours by industrial facilities and services to the individual pollution load in household sewage produced by one person in the same time. This refers to the amount of oxygen-demanding substances in wastewater which will consume oxygen as it bio-degrades, usually as a result of bacterial activity.

Equation and base value

A value frequently used in the international literature for PE, which was based on a German publication, is 54 gram of BOD per person per day. This has been adopted by many countries for design purposes but other values are also in use. For example, a commonly used definition used in Europe is: 1 PE equates to 60 gram of BOD per person per day, and it also equals 200 liters of sewage per day. In the United States, a figure of 80 grams BOD per day is normally used.
If the base value is taken as 60 grams of BOD per person per day, then the equation to calculate PE from an industrial wastewater is:

Population equivalents for industrial wastewaters

FoodCanning 1 ton processed500Pea processing1 ton processed85-400Tomato1 ton processed50-185Carrot1 ton processed160-390Potato1 ton processed215-545Citrus fruit1 ton processed55Chicken meat1 ton processed70-1600Beef1 ton processed20-600Fish1 ton processed300-2300Sweets/candies1 ton produced40-150Sugar cane1 ton produced50Dairy 1000 L milk20-100Dairy 1000 L milk100-800Margarine1 ton produced500Slaughter house1 cow / 2.5 pigs10-100Yeast production1 ton produced21000Confined animals breedingPigslive t.d35-100Dairy cattle live t.d1-2Cattlelive t.d65-150Horseslive t.d65-150Poultrylive t.d15-20Sugar-alcoholAlcohol distillation1 ton cane processed4000DrinksBrewery1 m3 produced150-350Soft drinks1 m3 produced50-100Wine1 m3 produced5TextilesCotton1 ton produced2800Wool1 ton produced5600Rayon1 ton produced550Nylon1 ton produced800Polyester1 ton produced3700Wool washing1 ton produced2000-4500Dyeing1 ton produced2000-3500Textile bleaching1 ton produced250-350Leather and tanneriesTanning1 ton hide processed1000-3500Shoes1000 pairs produced300Pulp and paperPulp1 ton produced600Paper1 ton produced100-300Pulp and paper integrated1 ton produced1000-10000Chemical industrialPaint1 employee20Soap1 ton produced1000Petroleum refinery1 barrel 1PVC1 ton produced200SteelworksFoundry1 ton pig iron produced12-30Lamination1 ton produced8-50