The Environmentalist

, Volume 28, Issue 2, pp 128–136 | Cite as

Dissolved oxygen sag analysis for a settling fields overlapping type multi-wastewater-outfall



The classical Streeter–Phelps models for Dissolved oxygen (DO) sag do not account for a significantly settleable portion (about 10% in treated to about 60% in the untreated wastewater discharged) of the total biochemical oxygen demand (BOD) inputs into rivers through wastewater outfalls, and therefore, they can not be used to predict the DO sag to any accuracy and rationality. The author’s rationally composited model for an accurate prediction of stream BOD, accounting for near linear removal of settleable BOD as well as simultaneous exponential decay of the non-settleable BOD, is used to predict the DO sag resulting from a multi-wastewater-outfall system, wherein the settling fields of some of the outfalls interfere and overlap. An illustrative case example has been presented to demonstrate use of the models evolved under varying locations of the multi-wastewater-outfalls. A universal and integrated PC based computer program can also be evolved for the computation of the overall resultant DO sag to confirm the manually computed DO sag.


DO sag analysis Settling fields overlapping type multi-outfalls system Stream DO prediction Drain’s overlapping settling fields Modeling of streams 


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  1. Bhargava DS (1983) Most rapid BOD assimilation in Ganga and Yamuna rivers. Journal of Environmental Engineering, American Society of Civil Engineers, vol 109, No. 1, Proc. Paper No. 17674, February, pp 174–188Google Scholar
  2. Bhargava DS (1986a) DO sag model for extremely fast river purification. Journal of Environmental Engineering, American Society of Civil Engineers, vol 112, No. 3, Paper No. 20696, June, pp 572–585Google Scholar
  3. Bhargava DS (1986b) Modelling for compounded DO sags. Civil Eng Trans, Institution of Engineers, Australia 28(3):222–230Google Scholar
  4. CBPCWP (1982) The Ganga basin Part I: the Yamuna sub-basin ADSORB/2/1980-81, Central Board for the Prevention and Control of Water Pollution, New Delhi, 1982Google Scholar
  5. Orford HE, Ingram WT (1953) Deoxygenation of sewage: critical review of the menomolecular formula. Sewage Ind Waste 25(4):419Google Scholar
  6. Streeter HW (1935) Measures of natural oxidation in polluted streams: 1. The oxygen demand factor. Sewage Work J 7(2):251Google Scholar
  7. Streeter MW, Phelps EE (1925) A study of the pollution and natural purification of the Ohio rivers. U.S. Pubic Health Serv Bull 146:35–42Google Scholar
  8. Thomas HA Jr (1940) Analysis of the biochemical oxygen demand curve. Sewage Work J 12(3):504Google Scholar
  9. Thomas HA Jr (1948) The pollution load capacity of streams. Water Sewage Work 95(11):409Google Scholar
  10. Velz CJ, Gannon JJ (1962) Biological extraction and accumulation in stream self-purification. Proceedings, 1st international conference on water pollution research, vol 1, London, England, pp 1Google Scholar

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  1. 1.Roorkee University (now IIT)RoorkeeIndia
  2. 2.AIT BangkokKlong LuangThailand
  3. 3.Devpura, HaridwarIndia

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