Population equivalent
Population equivalent or unit per capita loading, (PE), in waste-water treatment 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. It measures the amount of oxygen-demanding substances in waste water which will consume oxygen as it bio-degrades, usually as a result of bacterial activity.[1]
For practical calculations, it was assumed that one unit equalled 54 grams of Biochemical oxygen demand (BOD) per 24 hours, when the United Nations defined the term in 1997.[1] In Poland it is now assumed to be 60 grams per day,[2] and this is also the case within the European Union,[3] while in United States, a figure of 80 grams per day is normally used.[4]
The assumption is that one person living in a normal house will produce 200 litres of effluent per day, and that will contain 60 grams of biochemically active material. Thus a family of four living in a normal house would be expected to produce 800 litres of effluent, containing 240 grams of biochemically active material. The values vary for other situations, and so in Ireland, one guest staying in a hotel would typically produce 250 litres of effluent with 75 grams of active material, and so would have a population equivalent of 1.25.[5]
Population equivalents of wastewater from some industries[6] Type Activity BOD PE [inhab/(unit/d)]
Food Canning (fruit/vegetables) 500 Pea processing 85-400 Tomato 50-185 Carrot 160-390 Potato 215-545 Citrus fruit 55 Chicken meat 70-1600 Beef 20-600 Fish 300-2300 Sweets/candies 40-150 Sugar cane 50 Dairy (without cheese) 20-100 Dairy (with cheese) 100-800 Margarine 500 Slaughter house 10-100 Yeast production 21000 Confined animals breeding Pigs 35-100 Dairy cattle (milking room) 1-2 Cattle 65-150 Horses 65-150 Poultry 15-20 Sugar-alcohol Alcohol distillation 4000 Drinks Brewery 150-350 Soft drinks 50-100 Wine 5 Textiles Cotton 2800 Wool 5600 Rayon 550 Nylon 800 Polyester 3700 Wool washing 2000-4500 Dyeing 2000-3500 Textile bleaching 250-350 Leather and tanneries Tanning 1000-3500 Shoes 300 Pulp and paper Pulp 600 Paper 100-300 Pulp and paper integrated 1000-10000 Chemical industrial Paint 20 Soap 1000 Petroleum refinery 1 PVC 200 Steelworks Foundry 12-30 Lamination 8-50
Bibliography
- Rowe, Donald R.; Abdel-Magid, Isam Mohammed (1995). Handbook of Wastewater Reclamation and Reuse. CRC Press. ISBN 978-0-87371-671-0.CS1 maint: ref=harv (link)
References
- "Population Equivalent". Organisation for Economic Co-operation and Development. 20 November 2001. Archived from the original on 7 November 2013.
- "Central Statistical Office, Poland". Archived from the original on 14 May 2011.
- "Glossary of terms related to Urban Waste Water". European Commission. 7 August 2019. Archived from the original on 8 June 2019.
- Rowe & Abdel-Magid 1995, p. 171.
- "Sewage Parameters 3: Population Equivalent (PE) Part 1". Butler Manufacturing Services. 2013. Archived from the original on 19 June 2020.
- Marcos von Sperling; Carlos Augusto de Lemos Chernicharo (2005). Biological wastewater treatment in warm climate regions, vol. 1. IWA Publishing. p. 72. ISBN 978-1-84339-002-2.